Eyes provide peek at Alzheimer’s disease risk

August 23, 2021

Science Daily/University of California - San Diego

Amyloid plaques are protein deposits that collect between brain cells, hindering function and eventually leading to neuronal death. They are considered a hallmark of Alzheimer's disease (AD), and the focus of multiple investigations designed to reduce or prevent their formation, including the nationwide A4 study.

But amyloid deposits may also occur in the retina of the eye, often in patients clinically diagnosed with AD, suggesting similar pathologies in both organs. In a small, cross-sectional study, a team of researchers, led by scientists at University of California San Diego School of Medicine, compared tests of retinal and brain amyloids in patients from the A4 study and another study (Longitudinal Evaluation of Amyloid Risk and Neurodegeneration) assessing neurodegeneration risk in persons with low levels of amyloid.

Like the proverbial "windows to the soul," the researchers observed that the presence of retinal spots in the eyes correlated with brain scans showing higher levels of cerebral amyloid. The finding suggests that non-invasive retinal imaging may be useful as a biomarker for detecting early-stage AD risk.

The findings published in the August 17, 2021 issue of Alzheimer's & Dementia.

"This was a small initial dataset from the screening visit. It involved eight patients," said senior author Robert Rissman, PhD, professor of neurosciences at UC San Diego School of Medicine and director of the Biomarker Core for the Alzheimer's Disease Cooperative Study and Alzheimer's Disease Research Center at UC San Diego. "But these findings are encouraging because they suggest it may be possible to determine the onset, spread and morphology of AD -- a preclinical diagnosis -- using retinal imaging, rather than more difficult and costly brain scans. We look forward to seeing the results of additional timepoint retinal scans and the impact of solanezumab (a monoclonal antibody) on retinal imaging. Unfortunately we will need to wait to see and analyze these data when the A4 trial is completed."

The next step, said Rissman, will be to conduct a larger study to more fully document and ascertain the relationship between retinal amyloid and cerebral amyloid, both cross-sectionally and over time.

https://www.sciencedaily.com/releases/2021/08/210823125758.htm

Having a good listener improves your brain health

August 16, 2021

Science Daily/NYU Langone Health / NYU Grossman School of Medicine

Researchers find having someone to listen to you when you need to talk is associated with greater cognitive resilience. New study shows social interaction in adulthood can stave off cognitive decline despite brain aging.

Supportive social interactions in adulthood are important for your ability to stave off cognitive decline despite brain aging or neuropathological changes such as those present in Alzheimer's disease, a new study finds.

In the study publishing August 16 in JAMA Network Open, researchers observed that simply having someone available most or all of the time whom you can count on to listen to you when you need to talk is associated with greater cognitive resilience -- a measure of your brain's ability to function better than would be expected for the amount of physical aging- or disease-related changes in the brain, which many neurologists believe can be boosted by engaging in mentally stimulating activities, physical exercise, and positive social interactions.

"We think of cognitive resilience as a buffer to the effects of brain aging and disease," says lead researcher Joel Salinas, MD, the Lulu P. and David J. Levidow Assistant Professor of Neurology at NYU Grossman School of Medicine and member of the Department of Neurology's Center for Cognitive Neurology. "This study adds to growing evidence that people can take steps, either for themselves or the people they care about most, to increase the odds they'll slow down cognitive aging or prevent the development of symptoms of Alzheimer's disease -- something that is all the more important given that we still don't have a cure for the disease."

An estimated 5 million Americans are living with Alzheimer's disease, a progressive condition that affects mostly those over 65 and interferes with memory, language, decision-making, and the ability to live independently. Salinas says that while the disease usually affects an older population, the results of this study indicate that people younger than 65 would benefit from taking stock of their social support. For every unit of decline in brain volume, individuals in their 40s and 50s with low listener availability had a cognitive age that was four years older than those with high listener availability.

"These four years can be incredibly precious. Too often we think about how to protect our brain health when we're much older, after we've already lost a lot of time decades before to build and sustain brain-healthy habits," says Salinas. "But today, right now, you can ask yourself if you truly have someone available to listen to you in a supportive way, and ask your loved ones the same. Taking that simple action sets the process in motion for you to ultimately have better odds of long-term brain health and the best quality of life you can have."

Salinas also recommends that physicians consider adding this question to the standard social history portion of a patient interview: asking patients whether they have access to someone they can count on to listen to them when they need to talk. "Loneliness is one of the many symptoms of depression, and has other health implications for patients," says Salinas. "These kinds of questions about a person's social relationships and feelings of loneliness can tell you a lot about a patient's broader social circumstances, their future health, and how they're really doing outside of the clinic."

How the Study Was Conducted

Researchers used one of the longest running and most closely monitored community-based cohorts in the U.S., the Framingham Heart Study (FHS), as the source of their study's 2,171 participants, with an average age of 63. FHS participants self-reported information on the availability of supportive social interactions including listening, good advice, love and affection, sufficient contact with people they're close with, and emotional support.

Study participants' cognitive resilience was measured as the relative effect of total cerebral brain volume on global cognition, using MRI scans and neuropsychological assessments taken as part of the FHS. Lower brain volumes tend to associate with lower cognitive function, and in this study, researchers examined the modifying effect of individual forms of social support on the relationship between cerebral volume and cognitive performance.

The cognitive function of individuals with greater availability of one specific form of social support was higher relative to their total cerebral volume. This key form of social support was listener availability and it was highly associated with greater cognitive resilience.

Researchers note that further study of individual social interactions may improve understanding of the biological mechanisms that link psychosocial factors to brain health. "While there is still a lot that we don't understand about the specific biological pathways between psychosocial factors like listener availability and brain health, this study gives clues about concrete, biological reasons why we should all seek good listeners and become better listeners ourselves," says Salinas.

https://www.sciencedaily.com/releases/2021/08/210816112101.htm

Aerobic exercise after a sport-related concussion speeds recovery in adolescent athletes

Daily aerobic exercise significantly reduced the risk of prolonged recovery

September 30, 2021

Science Daily/University at Buffalo

Adolescents can speed their recovery after a sport-related concussion and reduce their risk of experiencing protracted recovery if they engage in aerobic exercise within 10 days of getting injured, according to a new University at Buffalo study.

Published Sept. 30 in The Lancet Child & Adolescent Health, the randomized controlled trial conducted by researchers at UB's Concussion Management Clinic reproduces and expands on the team's 2019 study published in JAMA Pediatrics.

The new study shows for the first time that sub-symptom threshold aerobic exercise -- meaning exercise that doesn't exacerbate symptoms -- when initiated within 10 days reduced a participant's risk of persistent post-concussion symptoms by 48%.

"The study clearly demonstrates that strict physical rest until symptoms spontaneously resolve is no longer an acceptable way to treat sport-related concussion in adolescents," said John J. Leddy, MD, first author, clinical professor of orthopaedics in the Jacobs School of Medicine and Biomedical Sciences at UB, and director of the UB Concussion Management Clinic at UBMD Orthopaedics and Sports Medicine.

Prescribing physical activity

"Our findings show that to accelerate recovery and reduce the risk of delayed recovery, physicians should not only permit, but they should consider prescribing sub-symptom threshold physical activity early after sport-related concussion," he said.

Adolescents are the most vulnerable age group for concussions, and they take the longest time to recover.

The new findings are the result of a large body of work by Leddy and colleague Barry S. Willer, PhD, professor of psychiatry in UB's Jacobs School, research director in the Concussion Management Clinic and senior author on the paper. Leddy and Willer have spent years investigating how concussions impact young athletes.

Their research, which is internationally known, has played a key role in the evolution of guidelines that no longer state that athletes recovering from concussions should be prescribed complete rest.

They began this line of research in 2000 after working together to develop guidelines for return to play after concussion for the International Olympics. They were interested in developing a safe and systematic assessment of exercise tolerance, since this was a known problem after concussion.

"We based our approach on how patients with heart disease are prescribed exercise, by identifying a safe threshold below which the patient can exercise," said Leddy. "We developed our Buffalo Concussion Treadmill Test by adapting a cardiac treadmill test to stress the brain instead of the heart. Since we know that regular aerobic exercise is good for brain health, the goal was to use sub-symptom threshold exercise to see if it could help the concussed brain recover."

Non-pharmacological, safe and effective

"As the current study shows, this approach is non-pharmacological, safe and effective," said Leddy, adding that no adverse events were reported.

Study participants were adolescents between the ages of 13 and 18 who had sustained a concussion while playing a sport. A total of 118 adolescents were included, with 61 receiving the aerobic exercise treatment and 57 receiving the placebo treatment of stretching exercises that did not elevate their heart rate.

Those who participated in the aerobic exercise group took a median of 14 days to recover from concussion versus 19 days for those in the stretching exercise group.

The current study differed from the team's 2019 study in the following ways:

• Two new sites were added. It was conducted with participants seen at UB-affiliated community sports medicine clinics, as well as two hospital-affiliated clinics: one at Children's Hospital of Philadelphia (connected with the University of Pennsylvania) and Boston Children's Hospital (connected to Harvard Medical School), which tend to see patients with more significant injuries.

• Whereas the previous study relied on participants self-reporting the amount and intensity of exercise they underwent, in the current trial all participants were provided with heart rate monitors to wear while exercising. This allowed the researchers to confirm that the participants actually followed the doctor's prescription for aerobic exercise.

• The study used a different research design called "intent to treat" and included all participants, even those who dropped out before completing the study, an approach that makes it more difficult to obtain positive findings, but which is more reflective of real-world concussion treatment.

The use of heart rate monitors, in particular, revealed to the UB researchers a more robust picture of the aerobic exercise sessions the participants were pursuing at home.

"What we discovered is that participants were quite diligent in following their prescription and further, that those who followed the prescription or may even have exceeded the exercise prescription of 20 minutes per day recovered much faster than those that did not follow the prescription," Willer said. "This finding is important because delayed recovery comes with substantial cost to adolescents, including academic difficulties, risk for depression and reduced quality of life."

Leddy and Willer said there are a number of possible reasons why this approach is effective, related to the physiological and neurological benefits that stem from aerobic exercise, including enhancements to neuroplasticity (i.e. neuron repair).

"We are very pleased that the results of this second study provide much stronger evidence that the Buffalo Protocol is not only effective, but it is effective whoever provides the treatment and with all adolescent athletes who experience a concussion," said Willer. "Importantly, the benefits of prescribed aerobic exercise were experienced by both genders equally."

The UB research focused exclusively on adolescents recovering from sport-related concussion. Other investigations, focused on adults who have sustained a concussion in a non-sport setting, have found that such an approach can be effective but it doesn't work as rapidly or effectively as it does for athletes. In adults, the aerobic exercise approach can work but, Leddy said, it usually has to be combined with other therapies.

"By contrast, this kind of sub-symptom aerobic exercise approach is often the only treatment that adolescent athletes need," he noted.

https://www.sciencedaily.com/releases/2021/09/210930213654.htm

Limiting screen time for young adults after concussion results in shorter duration of symptoms

September 8, 2021

Science Daily/University of Massachusetts Medical School

'A clinical trial of 125 young adults shows that those who limited screen time for 48 hours immediately after suffering a concussion had a significantly shorter duration of symptoms than those who were permitted screen time. These findings, published in JAMA Pediatrics, offer the first clinical evidence that restricting time spent at a computer, television or phone screen in the acute period following a concussion can reduce the duration of symptoms. The study supports preliminary clinical recommendations to limit screen time.

An estimated 2.5 million people go to the emergency department annually because of concussions. Many of these patients are children aged 10 to 19 years old. In 2017, 15 percent of high schoolers had reported being diagnosed at least once with a concussion.

The U.S. Centers for Disease Control and the International Concussion in Sports Group recommend a period of complete cognitive and physical rest for 24 to 48 hours following a concussion diagnosis. Yet, there are no clear guidelines regarding what constitutes cognitive rest during this period.

"It's one thing parents and children always ask in the emergency department," said lead author Theodore E. Macnow, MD, assistant professor of pediatrics. "Is screen time allowed?" The average American teen spends as much as seven hours a day in front of a screen, not including time spent doing schoolwork, and many clinicians caution against screen time following a concussion, said Dr. Macnow. Other clinicians, however, believe limited screen time, so long as it doesn't induce symptoms, is permittable as one of the few forms of safe distraction during this time. "We're still learning how to treat concussions and there are no clear recommendations regarding screen time," said Macnow. "Nobody has yet looked at this question in a rigorous way. We wanted to get a better handle on this question, so we conducted a randomized clinical trial." From June of 2018 to February of 2020, Macnow and colleagues assessed 125 patients age 12 to 25 who presented with a concussion to the Emergency Department at UMass Memorial Medical Center, the clinical partner of UMass Chan Medical School in Worcester. Patients were assessed and randomly placed in one of two cohorts. The first cohort was instructed to abstain from any electronic screens for 48 hours, while the second group was allowed any form of screen so long as it didn't induce symptoms. Both groups were advised to avoid work and schoolwork for the first 48 hours.

Patients completed a Post-Concussion Symptom Scale (PCSS) at the time of diagnosis and every day for the 10-day study. The PCSS is a 22-symptom scale, which grades each symptom from 0 (not present) to 6 (severe) and reliably detects change over time in concussed patients. In the absence of a head injury, a baseline score of less than 3 on the PCSS survey is considered normal. Additionally, patients completed a screen time survey on days one to three and an activity survey from days four to 10. An analysis of the data showed that the group permitted screen time during the initial 48 hours after a concussion experienced a significantly longer time to recover, measured by a PCSS score of less than three. On average, this group experienced a median time of eight days until symptom resolution compared to 3.5 days for the group that abstained from screen time. During this time, the cohort permitted screen time logged a median of 630 minutes over the 48-hour period while the cohort abstaining from screen time logged a median of 130 minutes.

"These findings support the conclusion that brief screen time abstinence following a concussion is associated with a faster recovery," said Macnow. "Given this data, preliminary clinical recommendations should be to limit screen time." Macnow added, "It's not clear why screen time exacerbated concussion symptoms but there are a lot of reasons to suspect it's not good." Macnow said. It's possible that electronic photons, which are known to triggers migraines, could play a role. Or that screen use may detract from sleep and resumption of normal activities, both of which are felt to be beneficial to concussion recovery. "These findings suggest that a larger, more diverse, multicenter study is warranted to see if the results are consistent," said Macnow. "What's more, we only looked at the first 48 hours after diagnosis. It would be worthwhile to see if abstaining from screen time longer had more of an impact or if specific screen time activities -- video games vs. television -- have a more pronounced effect on recovery time."

https://www.sciencedaily.com/releases/2021/09/210908180635.htm

Age and aging have critical effects on the gut microbiome

Study examines age-related changes to the small bowel

October 1, 2021

Science Daily Cedars-Sinai Medical Center

Researchers at Cedars-Sinai have found that aging produces significant changes in the microbiome of the human small intestine distinct from those caused by medications or illness burden. The findings have been published in the journal Cell Reports.

"By teasing out the microbial changes that occur in the small bowel with age, medication use and diseases, we hope to identify unique components of the microbial community to target for therapeutics and interventions that could promote healthy aging," said Ruchi Mathur, MD, the study's principal investigator.

Research exploring the gut microbiome, and its impact on health, has relied predominantly on fecal samples, which do not represent the entire gut, according to Mathur. In their study, investigators from Cedars-Sinai's Medically Associated Science and Technology (MAST) Program analyzed samples from the small intestine-which is over 20 feet in length and has the surface area of a tennis court-for examination of the microbiome and its relationship with aging.

"This study is the first of its kind to examine the microbial composition of the small intestine of subjects 18 years of age to 80. We now know that certain microbial populations are influenced more by medications, while others are more affected by certain diseases. We have identified specific microbes that appear to be only influenced by the chronological age of the person," said Mathur, an endocrinologist and director of the Diabetes Outpatient Treatment & Education Center.

The 21st century has been referred to as the "era of the gut microbiome" as scientists turn considerable attention to the role trillions of gut bacteria, fungi and viruses may play in human health and disease. The microbiome is the name given to the genes that live in these cells. Studies have suggested that disturbances in the constellations of the microbial universe may lead to critical illnesses, including gastroenterological diseases, diabetes, obesity, and some neurological disorders.

While researchers know that microbial diversity in stool decreases with age, Cedars-Sinai investigators identified bacteria in the small bowel they refer to as "disruptors" that increase and could be troublesome.

"Coliforms are normal residents of the intestine. We found that when these rod-shaped microbes become too abundant in the small bowel-as they do as we get older-they exert a negative influence on the rest of the microbial population. They are like weeds in a garden," said study co-author Gabriela Leite, PhD.

Investigators also found that as people age, the bacteria in the small intestine change from microbes that prefer oxygen to those that can survive with less oxygen, something they hope to understand as the research continues.

"Our goal is to identify and fingerprint the small intestinal microbial patterns of human health and disease. Given the important role the small bowel plays in absorption of nutrients, changes in the microbiome in this location of the gut may have a greater impact on human health, and warrants further study," said Mark Pimentel, MD, director of the MAST program and a co-author of the study.

This research is part of Cedars-Sinai's ongoing REIMAGINE study: Revealing the Entire Intestinal Microbiota and its Associations with the Genetic, Immunologic, and Neuroendocrine Ecosystem.

https://www.sciencedaily.com/releases/2021/10/211001135901.htm

Comparing seniors who relocate long-distance shows where you live affects your longevity

Analysis of Medicare data finds location matters, not just past health behavior.

September 1, 2021

Science Daily Massachusetts Institute of Technology

Moving to certain locations in the U.S. can have a significant impact on the longevity of senior citizens, according to new research.

Would you like to live longer? It turns out that where you live, not just how you live, can make a big difference.

That's the finding of an innovative study co-authored by an MIT economist, which examines senior citizens across the U.S. and concludes that some locations enhance longevity more than others, potentially for multiple reasons.

The results show that when a 65-year-old moves from a metro area in the 10th percentile, in terms of how much those areas enhance longevity, to a metro area the 90th percentile, it increases that person's life expectancy by 1.1 years. That is a notable boost, given that mean life expectancy for 65-year-olds in the U.S. is 83.3 years.

"There's a substantively important causal effect of where you live as an elderly adult on mortality and life expectancy across the United States," says Amy Finkelstein, a professor in MIT's Department of Economics and co-author of a newly published paper detailing the findings.

Researchers have long observed significant regional variation in life expectancy in the U.S., and often attributed it to "health capital" -- tendencies toward obesity, smoking, and related behavioral factors in the regional populations. But by analyzing the impact of moving, the current study can isolate and quantify the effect that the location itself has on residents.

As such, the research delivers important new information about large-scale drivers of U.S. health outcomes -- and raises the question of what it is about different places that affects the elderly's life expectancy. One clear possibility is the nature of available medical care. Other possible drivers of longevity include climate, pollution, crime, traffic safety, and more.

"We wanted to separate out the role of people's prior experiences and behaviors -- or health capital -- from the role of place or environment," Finkelstein says.

The paper, "Place-Based Drivers of Mortality: Evidence of Migration," is published in the August issue of the American Economic Review. The co-authors are Finkelstein, the John and Jennie S. MacDonald Professor of Economics at MIT, and Matthew Gentzkow and Heidi Williams, who are both professors of economics at Stanford University.

Comparing movers to see how place matters

To conduct the study, Finkelstein, Gentzkow, and Williams analyzed Medicare records from 1999 to 2014, focusing on U.S. residents between the ages of 65 and 99. Ultimately the research team studied 6.3 million Medicare beneficiaries. About 2 million of those moved from one U.S. "commuting zone" to another, and the rest were a random 10 percent sample of people who had not moved over the 15-year study period. (The U.S. Census Bureau defines about 700 commuting zones nationally.)

A central element of the study involves seeing how different people who were originally from the same locations fared when moving to different destinations. In effect, says Finkelstein, "The idea is to take two elderly people from a given origin, say, Boston. One moves to low-mortality Minneapolis, one moves to high-mortality Houston. We then compare how long each lives after they move."

Different people have different health profiles before they move, of course. But Medicare records include detailed claims data, so the researchers applied records of 27 different illnesses and conditions -- ranging from lung cancer and diabetes to depression -- to a standard mortality risk model, to categorize the overall health of seniors when they move. Using these "very, very rich pre-move measures of their health," Finkelstein notes, the researchers tried to account for pre-existing health levels of seniors from the same location who moved to different places.

Still, even assessing people by 27 measures does not completely describe their health, so Finkelstein, Gentzkow, and Williams also estimated what fraction of people's health conditions they had not observed -- essentially by calibrating the observed health of seniors against health capital levels in places they were moving from. They then consider how observed health varies across individuals from the same location moving to different destinations and, assuming that differences in unobserved health -- such as physical mobility -- vary in the same way as observed differences in health, they adjust their estimates accordingly.

All told, the study found that many urban areas on the East and West Coasts -- including New York City, San Francisco, and Miami -- have positive effects on longevity for seniors moving there. Some Midwestern metro areas, including Chicago, also score well.

By contrast, a large swath of the deep South has negative effects on longevity for seniors moving there, including much of Alabama, Arkansas, Louisiana, and northern Florida. Much of the Southwest, including parts of Texas, Oklahoma, New Mexico, and Arizona, fares similarly poorly.

The scholars also estimate that health capital accounts for about 70 percent of the difference in longevity across areas of the U.S., and that location effects account for about 15 percent of the variation.

"Yes, health capital is important, but yes, place effects also matter," Finkelstein says.

The Charlotte Effect: What makes a difference?

Indeed, the significance of place effects on life expectancy is also evident in another pattern the study found. Some locations -- such as Charlotte, North Carolina -- have a positive effect on longevity but still have low overall life expectancy, while other places -- such as Santa Fe New Mexico -- have high overall life expectancy, but a below-average effect on the longevity of seniors who move there.

Again, the life expectancy of an area's population is not the same thing as that location's effect on longevity. In places where, say, smoking is highly prevalent, population-wide longevity might be subpar, but other factors might make it a place where people of average health will live longer. The question is why.

"Our [hard] evidence is about the role of place," Finkelstein says, while noting that the next logical step in this vein of research is to look for the specific factors at work. "We know something about Charlotte, North Carolina, makes a difference, but we don't yet know what."

With that in mind, Finkelstein, Gentzkow, and Williams, along with other colleagues, are working on a pair of new studies about health care practices to see what impact place-based differences may have; one study focuses on doctors, and the other looks at the prescription opioid epidemic.

In the background of this research is a high-profile academic and policy discussion about the impact of health care utilization. One perspective, associated with the Dartmouth Atlas of Health Care project, suggests that the large regional differences in health care use it has documented have little impact on mortality. But the current study, by quantifying the variable impact of place, suggest there may be, in turn, a bigger differential impact in health care utilization yet to be identified.

For her part, Finkelstein says she would welcome further studies digging into health care use or any other factor that might explain why different places have different effects on life expectancy; the key is uncovering more hard evidence, wherever it leads.

"Differences in health care across places are large and potentially important," Finkelstein says. "But there are also differences in pollution, weather, [and] other aspects. … What we need to do now is get inside the black box of 'the place' and figure out what it is about them that matters for longevity."

https://www.sciencedaily.com/releases/2021/09/210901113734.htm

Key mental abilities can actually improve during aging

August 19, 2021

Science Daily Georgetown University Medical Center

It's long been believed that advancing age leads to broad declines in our mental abilities. Now new research from Georgetown University Medical Center offers surprisingly good news by countering this view.

The findings, published August 19, 2021, in Nature Human Behaviour, show that two key brain functions, which allow us to attend to new information and to focus on what's important in a given situation, can in fact improve in older individuals. These functions underlie critical aspects of cognition such as memory, decision making, and self-control, and even navigation, math, language, and reading.

"These results are amazing, and have important consequences for how we should view aging," says the study's senior investigator, Michael T. Ullman, PhD, a professor in the Department of Neuroscience, and Director of Georgetown's Brain and Language Lab.

"People have widely assumed that attention and executive functions decline with age, despite intriguing hints from some smaller-scale studies that raised questions about these assumptions," he says. "But the results from our large study indicate that critical elements of these abilities actually improve during aging, likely because we simply practice these skills throughout our life."

"This is all the more important because of the rapidly aging population, both in the US and around the world," Ullman says. He adds that with further research, it may be possible to deliberately improve these skills as protection against brain decline in healthy aging and disorders.

The research team, which includes first author João Veríssimo, PhD, an assistant professor at the University of Lisbon, Portugal, looked at three separate components of attention and executive function in a group of 702 participants aged 58 to 98. They focused on these ages since this is when cognition often changes the most during aging.

The components they studied are the brain networks involved in alerting, orienting, and executive inhibition. Each has different characteristics and relies on different brain areas and different neurochemicals and genes. Therefore, Ullman and Veríssimo reasoned, the networks may also show different aging patterns.

Alerting is characterized by a state of enhanced vigilance and preparedness in order to respond to incoming information. Orientinginvolves shifting brain resources to a particular location in space. The executive network inhibits distracting or conflicting information, allowing us to focus on what's important.

"We use all three processes constantly," Veríssimo explains. "For example, when you are driving a car, alerting is your increased preparedness when you approach an intersection. Orienting occurs when you shift your attention to an unexpected movement, such as a pedestrian. And executive function allows you to inhibit distractions such as birds or billboards so you can stay focused on driving."

The study found that only alerting abilities declined with age. In contrast, both orienting and executive inhibition actually improved.

The researchers hypothesize that because orienting and inhibition are simply skills that allow people to selectively attend to objects, these skills can improve with lifelong practice. The gains from this practice can be large enough to outweigh the underlying neural declines, Ullman and Veríssimo suggest. In contrast, they believe that alerting declines because this basic state of vigilance and preparedness cannot improve with practice.

"Because of the relatively large number of participants, and because we ruled out numerous alternative explanations, the findings should be reliable and so may apply quite broadly," Veríssimo says. Moreover, he explains that "because orienting and inhibitory skills underlie numerous behaviors, the results have wide-ranging implications."

"The findings not only change our view of how aging affects the mind, but may also lead to clinical improvements, including for patients with aging disorders such as Alzheimer's disease," says Ullman.

https://www.sciencedaily.com/releases/2021/08/210819113017.htm

Healthy changes in diet, activity improved treatment-resistant high blood pressure

September 27, 2021

Science Daily/American Heart Association

People with treatment-resistant hypertension successfully reduced their blood pressure by adopting the Dietary Approaches to Stop Hypertension (DASH) eating plan, losing weight and improving their aerobic fitness by participating in a structured diet and exercise program at a certified cardiac rehabilitation facility, according to new research published today in the American Heart Association's flagship journal Circulation.

Uncontrolled high blood pressure (130/80 mm Hg or higher) despite the use of three or more medications of different classes including a diuretic to reduce blood pressure is a condition known as resistant hypertension. Although estimates vary, resistant hypertension likely affects about 5% of the general global population and may affect 20% to 30% of adults with high blood pressure. Resistant hypertension is also associated with end-organ damage and a 50% greater risk of adverse cardiovascular events, including stroke, heart attack and death.

Diet and exercise are well-established treatments for high blood pressure. In June 2021, the American Heart Association advised that physical activity is the optimal first treatment choice for adults with mild to moderately elevated blood pressure and blood cholesterol who otherwise have low heart disease risk.

This new study, Treating Resistant Hypertension Using Lifestyle Modification to Promote Health (TRIUMPH), is the first to evaluate the impact of lifestyle modifications in people with resistant hypertension. Researchers found that behavioral changes, including regular aerobic exercise, adoption of the DASH (Dietary Approaches to Stop Hypertension) diet, reducing salt consumption and losing weight, can lower blood pressure significantly and improve cardiovascular health in people with resistant hypertension. The DASH eating plan is rich in fruits, vegetables, low-fat dairy products and limited salt, and aligns with the American Heart Association's nutrition recommendations.

The four-month clinical trial involved 140 adults with resistant hypertension (average age 63; 48% women; 59% Black adults; 31% with type 2 diabetes; and 21% with chronic kidney disease). Participants were randomly divided into two groups -- 90 participants received weekly dietary counseling and exercise training in an intensive, supervised cardiac rehabilitation setting three times a week. The other 50 participants received a single informational session from a health educator and written guidelines on exercise, weight loss and nutritional goals to follow on their own.

Researchers found:

• The participants in the supervised program had about a 12-point drop in systolic blood pressure, compared to 7 points in the self-guided group. Systolic blood pressure (the first number in a blood pressure reading) indicates how much pressure blood is exerting against artery walls when the heart beats and is recognized as a major risk factor for cardiovascular disease for adults ages 50 and older.

• Blood pressure measures captured through 24 hours of ambulatory monitoring during a typical day revealed that the group in the supervised lifestyle program had a 7-point reduction in systolic blood pressure, while the self-guided group had no change in blood pressure.

• Participants in the supervised program also had greater improvements in other key indicators of heart health, suggesting that they had a lower risk of a heart event in the future.

"Our findings showed lifestyle modifications among people with resistant hypertension can help them successfully lose weight and increase their physical activity, and as a result, lower blood pressure and potentially reduce their risk of heart attack or stroke," said James A. Blumenthal, Ph.D., first and senior author of the study, and J.P. Gibbons Professor of Psychiatry and Behavioral Sciences at Duke University School of Medicine in Durham, North Carolina. "While some people can make lifestyle changes on their own, a structured program of supervised exercise and dietary modifications conducted by a multidisciplinary team of health care professionals in cardiac rehabilitation programs is likely more effective."

Blumenthal noted that the success of the supervised program doesn't mean people with resistant hypertension can stop taking their medications; however, it suggests that they may want to talk with their physicians about possibly reducing the dosages or altering their medications based upon their lowered blood pressure values.

The study was conducted at a single institution -- Duke University School of Medicine -- so findings may not be generalizable to broader groups of people. However, the intensive, structured, supervised part of the study occurred at several representative cardiac rehabilitation centers in central North Carolina, with educational and cultural diversity well represented. Researchers believe the program could be implemented with success at similar cardiac rehabilitation centers throughout the county. Also, the study's impact beyond the four months of monitoring is limited by whether participants who made significant lifestyle changes will maintain them. "The benefits of the lifestyle modifications may be reduced unless the healthy lifestyle habits can be maintained," Blumenthal said.

"The most important point is that it is not too late to lower blood pressure by making healthy lifestyle choices," he said. "Adopting a healthy lifestyle pays huge dividends, even for people whose blood pressure remains elevated despite being on three or more antihypertensive medications."

American Heart Association volunteer expert Bethany Barone Gibbs, Ph.D., FAHA, noted that this data gives clinicians another evidence-based tool for helping patients with resistant hypertension.

"Though we usually think about recommending lifestyle changes like losing weight and getting more physical activity before starting medications, this study provides important reinforcement that adding lifestyle changes in conjunction with medications -- and when medications alone are not doing the job -- is an effective strategy," said Gibbs, an associate professor in the department of health and human development and clinical and translational sciences at the University of Pittsburgh. "Also exciting is that Blumenthal, et. al., used a cardiac rehab model, which can be duplicated in many settings."

Gibbs, chair of the statement writing group of the Association's June 2021 scientific statement on lifestyle treatment for hypertension, urged patients to commit to lifestyle changes -- losing 5% to 10% of their bodyweight, greater adherence to the DASH-style diet, and increasing steps by at least 1,000 per day can yield health benefits.

https://www.sciencedaily.com/releases/2021/09/210927092147.htm

Strength training can burn fat too, myth-busting study finds

September 22, 2021

Science Daily/University of New South Wales

It's basic exercise knowledge that to gain muscles, you strength train, and to lose fat, you do cardio -- right?

Not necessarily, a new UNSW study published this week in Sports Medicine suggests.

In fact, the study -- a systematic review and meta-analysis that reviewed and analysed existing evidence -- shows we can lose around 1.4 per cent of our entire body fat through strength training alone, which is similar to how much we might lose through cardio or aerobics.

"A lot of people think that if you want to lose weight, you need to go out and run," says senior author of the study Dr Mandy Hagstrom, exercise physiologist and senior lecturer at UNSW Medicine & Health.

"But our findings show that even when strength training is done on its own, it still causes a favourable loss of body fat without having to consciously diet or go running."

Up until now, the link between strength training and fat loss has been unclear. Studies have investigated this link in the past, but their sample sizes tend to be small -- a side effect of not many people wanting to volunteer to exercise for months on end. Smaller sample sizes can make it difficult to find statistically significant results, especially as many bodies can respond differently to exercise programs.

"It can be really difficult to discern whether there's an effect or not based on one study alone," says Dr Hagstrom. "But when we add all of these studies together, we effectively create one large study, and can get a much clearer idea of what's going on."

Dr Hagstrom and her team pulled together the findings from 58 research papers that used highly accurate forms of body fat measurement (like body scans, which can differentiate fat mass from lean mass) to measure the outcomes from strength training programs. Altogether, the studies included 3000 participants, none of which had any previous weight training experience.

While the strength training programs differed between the studies, the participants worked out for roughly 45-60 minutes each session for an average of 2.7 times per week. The programs lasted for about five months.

The team found that, on average, the participants lost 1.4 per cent of their total body fat after their training programs, which equated to roughly half a kilo in fat mass for most participants.

While the findings are encouraging for fans of pumping iron, Dr Hagstrom says the best approach for people who are aiming to lose fat is still to stick to eating nutritiously and having an exercise routine that includes both aerobic/cardio and strength training.

But if aerobics and cardio just aren't your thing, the good news is you don't need to force it.

"If you want to exercise to change your body composition, you've got options," says Dr Hagstrom.

"Do what exercise you want to do and what you're most likely to stick to."

Busting the fat loss myth

Part of the reason many people think strength training doesn't live up to cardio in terms of fat loss comes down to inaccurate ways of measuring fat.

For example, many people focus on the number they see on the scale -- that is, their total body weight. But this figure doesn't differentiate fat mass from everything else that makes up the body, like water, bones and muscles.

"More often than not, we don't gain any muscle mass when we do aerobic training," says Dr Hagstrom. "We improve our cardiorespiratory fitness, gain other health and functional benefits, and can lose body fat.

"But when we strength train, we gain muscle mass and lose body fat, so the number on the scales won't look as low as it would after aerobics training, especially as muscle weighs more than fat."

The research team focused on measuring how much the total body fat percentage -- that is, the amount of your body that's made up of fat mass -- changed after strength training programs. This measurement showed fat loss appears to be on par with aerobics and cardio training, despite the different figures on the scales.

"A lot of fitness recommendations come from studies that use inaccurate measurement tools, like bioelectrical impedance or scales," says Dr Hagstrom.

"But the most accurate and reliable way of assessing body fat is through DEXA, MRI or CT scans. They can compartmentalise the body and separate fat mass from lean tissue."

While this study didn't show whether variables like exercise duration, frequency, intensity, or set volume impacted fat loss percentage, the team hope to next investigate whether how we strength train can change the amount of fat loss.

A better way of measuring progress

As part of their study, the team conducted a sub-analysis comparing how different ways of measuring fat can influence a study's findings.

Interestingly, it showed that when papers used more accurate measurements like body scans, they tended to show lower overall changes in body fat.

"Using accurate fat measurements is important because it gives us a more realistic idea of what body changes to expect," says lead author of the study Mr Michael Wewege, PhD candidate at UNSW and NeuRA.

"Future exercise studies can improve their research by using these more accurate body measurements."

Reframing the way we measure progress doesn't just apply to sports researchers, but to everyday people, too.

"Resistance training does so many fantastic things to the body that other forms of exercise don't, like improving bone mineral density, lean mass and muscle quality. Now, we know it also gives you a benefit we previously thought only came from aerobics," says Dr Hagstrom.

"If you're strength training and want to change how your body looks, then you don't want to focus on the number on the scale too much, because it won't show you all your results.

"Instead, think about your whole body composition, like how your clothes fit and how your body will start to feel, and move, differently."

https://www.sciencedaily.com/releases/2021/09/210922121905.htm

Sticking to low-fat dairy may not be the only heart healthy option

September 21, 2021

Science Daily/George Institute for Global Health

New research amongst the world's biggest consumers of dairy foods has shown that those with higher intakes of dairy fat -- measured by levels of fatty acids in the blood -- had a lower risk of cardiovascular disease compared to those with low intakes. Higher intakes of dairy fat were not associated with an increased risk of death.

Researchers then combined the results of this study in just over 4,000 Swedish adults with those from 17 similar studies in other countries, creating the most comprehensive evidence to date on the relationship between this more objective measure of dairy fat consumption, risk of cardiovascular disease (CVD) and death.

Dr Matti Marklund from The George Institute for Global Health, Johns Hopkins Bloomberg School of Public Health, and Uppsala University said that with dairy consumption on the rise worldwide, a better understanding of the health impact was needed.

"Many studies have relied on people being able to remember and record the amounts and types of dairy foods they've eaten, which is especially difficult given that dairy is commonly used in a variety of foods.

"Instead, we measured blood levels of certain fatty acids, or fat 'building blocks' that are found in dairy foods, which gives a more objective measure of dairy fat intake that doesn't rely on memory or the quality of food databases," he added.

"We found those with the highest levels actually had the lowest risk of CVD. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods."

Dairy and dairy product consumption in Sweden is among the highest worldwide. An international collaboration between researchers in Sweden, the US and Australia assessed dairy fat consumption in 4150 Swedish 60-year-olds by measuring blood levels of a particular fatty acid that is mainly found in dairy foods and therefore can be used to reflect intake of dairy fat.

They were then followed up for an average of 16 years to see how many had heart attacks, strokes and other serious circulatory events, and how many died from any cause during this time.

After statistically adjusting for other known CVD risk factors including things like age, income, lifestyle, dietary habits, and other diseases, the CVD risk was lowest for those with high levels of the fatty acid (reflecting high intake of dairy fats). Those with the highest levels had no increased risk of death from all causes.

Dr Marklund added that the findings highlight the uncertainty of evidence in this area, which is reflected in dietary guidelines.

"While some dietary guidelines continue to suggest consumers choose low-fat dairy products, others have moved away from that advice, instead suggesting dairy can be part of a healthy diet with an emphasis on selecting certain dairy foods -- for example, yoghurt rather than butter -- or avoiding sweetened dairy products that are loaded with added sugar," he said.

Combining these results with 17 other studies involving a total of almost 43,000 people from the US, Denmark, and the UK confirmed these findings in other populations.

"While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat per se," Dr Marklund said.

Lead author Dr Kathy Trieu from The George Institute for Global Health said that consumption of some dairy foods, especially fermented products, have previously been associated with benefits for the heart.

"Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type -- such as cheese, yoghurt, milk, and butter -- rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health," she said.

"Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health."

"It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts, and non-tropical vegetable oils can have greater health benefits than dairy fats," Dr Trieu added.

https://www.sciencedaily.com/releases/2021/09/210921140119.htm

Gut microbiota influences the ability to lose weight

September 14, 2021

Science Daily/American Society for Microbiology

Gut microbiota influences the ability to lose weight in humans, according to new research. The findings were published this week in mSystems, an open-access journal of the American Society for Microbiology.

"Your gut microbiome can help or cause resistance to weight loss and this opens up the possibility to try to alter the gut microbiome to impact weight loss," said lead study author Christian Diener, Ph.D., a research scientist at the Institute for Systems Biology in Seattle, Washington.

To conduct their research, Dr. Diener and colleagues focused on a large cohort of individuals who were involved in a lifestyle intervention study. Instead of a specific diet or exercise program, this intervention involved a commercial behavioral coaching program paired with advice from a dietician and nurse coach. The researchers focused on 48 individuals who lost more than 1% of their body weight per month over a 6 to 12 month period and 57 individuals who did not lose any weight and had a stable body mass index (BMI) over the same period. The researchers relied on metagenomics, the study of genetic material recovered from blood and stool samples. The individuals analyzed blood metabolites, blood proteins, clinical labs, dietary questionnaires and gut bacteria in the two groups.

After controlling for age, sex and baseline BMI, the researchers identified 31 baseline stool metagenomic functional features that were associated with weight loss responses. These included complex polysaccharide and protein degradation genes, stress-response genes, respiration-related genes, cell wall synthesis genes and gut bacterial replication rates. A major finding was that the ability of the gut microbiome to break down starches was increased in people who did not lose weight. Another key finding was that genes that help bacteria grow faster, multiply, replicate and assemble cell walls were increased in people who lost more weight.

"Before this study, we knew the composition of bacteria in the gut were different in obese people than in people who were non-obese, but now we have seen that there are a different set of genes that are encoded in the bacteria in our gut that also responds to weight loss interventions," said Dr. Diener. "The gut microbiome is a major player in modulating whether a weight loss intervention will have success or not. The factors that dictate obesity versus nonobesity are not the same factors that dictate whether you will lose weight on a lifestyle intervention."

Research has already shown that if you change your diet, you can alter the composition of bacteria in your gut. According to Dr. Diener, if someone has a composition of gut bacterial genes that confers resistance to weight loss, then perhaps you can alter their diet to shift to a composition that would help them lose weight.

https://www.sciencedaily.com/releases/2021/09/210914135522.htm

Scientists claim that overeating is not the primary cause of obesity

September 13, 2021

Science Daily/American Society for Nutrition

Statistics from the Centers for Disease Control and Prevention (CDC) show that obesity affects more than 40% of American adults, placing them at higher risk for heart disease, stroke, type 2 diabetes, and certain types of cancer. The USDA's Dietary Guidelines for Americans 2020 -- 2025 further tells us that losing weight "requires adults to reduce the number of calories they get from foods and beverages and increase the amount expended through physical activity."

This approach to weight management is based on the century-old energy balance model which states that weight gain is caused by consuming more energy than we expend. In today's world, surrounded by highly palatable, heavily marketed, cheap processed foods, it's easy for people to eat more calories than they need, an imbalance that is further exacerbated by today's sedentary lifestyles. By this thinking, overeating, coupled with insufficient physical activity, is driving the obesity epidemic. On the other hand, despite decades of public health messaging exhorting people to eat less and exercise more, rates of obesity and obesity-related diseases have steadily risen.

The authors of "The Carbohydrate-Insulin Model: A Physiological Perspective on the Obesity Pandemic," a perspective published in The American Journal of Clinical Nutrition, point to fundamental flaws in the energy balance model, arguing that an alternate model, the carbohydrate-insulin model, better explains obesity and weight gain. Moreover, the carbohydrate-insulin model points the way to more effective, long-lasting weight management strategies.

According to lead author Dr. David Ludwig, Endocrinologist at Boston Children's Hospital and Professor at Harvard Medical School, the energy balance model doesn't help us understand the biological causes of weight gain: "During a growth spurt, for instance, adolescents may increase food intake by 1,000 calories a day. But does their overeating cause the growth spurt or does the growth spurt cause the adolescent to get hungry and overeat?"

In contrast to the energy balance model, the carbohydrate-insulin model makes a bold claim: overeating isn't the main cause of obesity. Instead, the carbohydrate-insulin model lays much of the blame for the current obesity epidemic on modern dietary patterns characterized by excessive consumption of foods with a high glycemic load: in particular, processed, rapidly digestible carbohydrates. These foods cause hormonal responses that fundamentally change our metabolism, driving fat storage, weight gain, and obesity.

When we eat highly processed carbohydrates, the body increases insulin secretion and suppresses glucagon secretion. This, in turn, signals fat cells to store more calories, leaving fewer calories available to fuel muscles and other metabolically active tissues. The brain perceives that the body isn't getting enough energy, which, in turn, leads to feelings of hunger. In addition, metabolism may slow down in the body's attempt to conserve fuel. Thus, we tend to remain hungry, even as we continue to gain excess fat.

To understand the obesity epidemic, we need to consider not only how much we're eating, but also how the foods we eat affect our hormones and metabolism. With its assertion that all calories are alike to the body, the energy balance model misses this critical piece of the puzzle.

While the carbohydrate-insulin model is not new -- its origins date to the early 1900s -- The American Journal of Clinical Nutritionperspective is the most comprehensive formulation of this model to date, authored by a team of 17 internationally recognized scientists, clinical researchers, and public health experts. Collectively, they have summarized the growing body of evidence in support of the carbohydrate-insulin model. Moreover, the authors have identified a series of testable hypotheses that distinguish the two models to guide future research.

Adoption of the carbohydrate-insulin model over the energy-balance model has radical implications for weight management and obesity treatment. Rather than urge people to eat less, a strategy which usually doesn't work in the long run, the carbohydrate-insulin model suggests another path that focuses more on what we eat. According to Dr. Ludwig, "reducing consumption of the rapidly digestible carbohydrates that flooded the food supply during the low-fat diet era lessens the underlying drive to store body fat. As a result, people may lose weight with less hunger and struggle."

The authors acknowledge that further research is needed to conclusively test both models and, perhaps, to generate new models that better fit the evidence. Toward this end, they call for constructive discourse and "collaborations among scientists with diverse viewpoints to test predictions in rigorous and unbiased research."

https://www.sciencedaily.com/releases/2021/09/210913135729.htm

Eating walnuts daily lowered 'bad' cholesterol and may reduce cardiovascular disease risk

August 30, 2021

Science Daily/American Heart Association

Healthy older adults who ate a handful of walnuts (about ½ cup) a day for two years modestly lowered their level of low-density lipoprotein or LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk. The study explored the effects of a walnut-enriched diet on overall cholesterol in elderly individuals from diverse geographical locations and spanning two years.

Eating about ½ cup of walnuts every day for two years modestly lowered levels of low-density lipoprotein (LDL) cholesterol, known as "bad cholesterol," and reduced the number of total LDL particles and small LDL particles in healthy, older adults, according to new research published today in the American Heart Association's flagship journal Circulation.

Healthy older adults who ate a handful of walnuts (about ½ cup) a day for two years modestly lowered their level of low-density lipoprotein or LDL cholesterol levels. Consuming walnuts daily also reduced the number of LDL particles, a predictor of cardiovascular disease risk.

Walnuts are a rich source of omega-3 fatty acids (alpha-linolenic acid), which have been shown to have a beneficial effect on cardiovascular health.

"Prior studies have shown that nuts in general, and walnuts in particular, are associated with lower rates of heart disease and stroke. One of the reasons is that they lower LDL-cholesterol levels, and now we have another reason: they improve the quality of LDL particles," said study co-author Emilio Ros, M.D., Ph.D., director of the Lipid Clinic at the Endocrinology and Nutrition Service of the Hospital Clínic of Barcelona in Spain. "LDL particles come in various sizes. Research has shown that small, dense LDL particles are more often associated with atherosclerosis, the plaque or fatty deposits that build up in the arteries. Our study goes beyond LDL cholesterol levels to get a complete picture of all of the lipoproteins and the impact of eating walnuts daily on their potential to improve cardiovascular risk."

In a sub-study of the Walnuts and Healthy Aging study, a large, two-year randomized controlled trial examining whether walnuts contribute to healthy aging, researchers evaluated if regular walnut consumption, regardless of a person's diet or where they live, has beneficial effects on lipoproteins.

This study was conducted from May 2012 to May 2016 and involved 708 participants between the ages of 63 and 79 (68% women) who were healthy, independent-living adults residing in Barcelona, Spain, and Loma Linda, California.

Participants were randomly divided into two groups: active intervention and control. Those allocated to the intervention group added about a half cup of walnuts to their usual daily diet, while participants in the control group abstained from eating any walnuts. After two years, participants' cholesterol levels were tested, and the concentration and size of lipoproteins were analyzed by nuclear magnetic resonance spectroscopy. This advanced test enables physicians to more accurately identify lipoprotein features known to relate to the risk of cardiovascular disease.

The two-year study had a 90% retention rate (632 participants completed the study). Complete lipoprotein analyses were available in 628.

Among key findings of all study participants:

• At 2 years, participants in the walnut group had lower LDL cholesterol levels -- by an average of 4.3 mg/dL, and total cholesterol was lowered by an average of 8.5 mg/dL.

• Daily consumption of walnuts reduced the number of total LDL particles by 4.3% and small LDL particles by 6.1%. These changes in LDL particle concentration and composition are associated with a lower risk of cardiovascular disease.

• Intermediate Density Lipoprotein (IDL) cholesterol also decreased. It is known that IDL cholesterol is a precursor to LDL and refers to a density between that of low-density and very-low-density lipoproteins. In the last decade, IDL cholesterol has emerged as a relevant lipid cardiovascular risk factor independent of LDL cholesterol.

• LDL cholesterol changes among the walnut group differed by sex; in men, LDL cholesterol fell by 7.9% and in women by 2.6%.

"While this is not a tremendous decrease in LDL cholesterol, it's important to note that at the start of the study all our participants were quite healthy, free of major non-communicable diseases. However, as expected in an elderly population, close to 50% of participants were being treated for both high blood pressure and hypercholesterolemia. Thanks in part to statin treatment in 32%, the average cholesterol levels of all the people in our study were normal," Ros said. "For individuals with high blood cholesterol levels, the LDL cholesterol reduction after a nut-enriched diet may be much greater."

"Eating a handful of walnuts every day is a simple way to promote cardiovascular health. Many people are worried about unwanted weight gain when they include nuts in their diet," Ros said. "Our study found that the healthy fats in walnuts did not cause participants to gain weight."

The major limitation of this investigation is that both participants and researchers knew who was and was not eating walnuts. However, the study did involve two very different populations with distinct diets. "The outcomes were similar in both groups, so we can safely apply the results of this study to other populations," Ros said. More research is also needed to clarify the different LDL results in men and women.

According to the American Heart Association, walnuts are especially high in omega-3 fatty acids, the same heart-healthy fat found in oily fish. A serving size is a small handful or 1.5 ounces of whole nuts or 2 tablespoons of nut butter.

The study was funded by the California Walnut Commission.

https://www.sciencedaily.com/releases/2021/08/210830081805.htm

Reducing sugar in packaged foods can prevent disease in millions

August 27, 2021

Science Daily/Massachusetts General Hospital

Cutting 20% of sugar from packaged foods and 40% from beverages could prevent 2.48 million cardiovascular disease events (such as strokes, heart attacks, cardiac arrests), 490,000 cardiovascular deaths, and 750,000 diabetes cases in the U.S. over the lifetime of the adult population, according to micro-simulation study published in Circulation.

A team of researchers from Massachusetts General Hospital (MGH), the Friedman School of Nutrition Science & Policy at Tufts University, Harvard T.H. Chan School of Public Health and New York City Department of Health and Mental Hygiene (NYC DOH) created a model to simulate and quantify the health, economic, and equity impacts of a pragmatic sugar-reduction policy proposed by the U.S. National Salt and Sugar Reduction Initiative (NSSRI). A partnership of more than 100 local, state and national health organizations convened by the NYC DOH, the NSSRI released draft sugar-reduction targets for packaged foods and beverages in 15 categories in 2018. This February, NSSRI finalized the policy with the goal of industry voluntarily committing to gradually reformulate their sugary products.

Implementing a national policy, however, will require government support to monitor companies as they work toward the targets and to publicly report on their progress. The researchers hope their model will build consensus on the need for a national-sugar reformulation policy in the US. "We hope that this study will help push the reformulation initiative forward in the next few years," says Siyi Shangguan, MD, MPH, lead author and attending physician at MGH. "Reducing the sugar content of commercially prepared foods and beverages will have a larger impact on the health of Americans than other initiatives to cut sugar, such as imposing a sugar tax, labeling added sugar content, or banning sugary drinks in schools."

Ten years after the NSSRI policy goes into effect, the U.S. could expect to save $4.28 billion in total net healthcare costs, and $118.04 billion over the lifetime of the current adult population (ages 35 to 79), according to the model. Adding the societal costs of lost productivity of Americans developing diseases from excessive sugar consumption, the total cost savings of the NSSRI policy rises to $160.88 billion over the adult population's lifetime. These benefits are likely to be an underestimation since the calculations were conservative. The study also demonstrated that even partial industry compliance with the policy could generate significant health and economic gains.

The researchers found that the NSSRI policy became cost-effective at six years and cost-saving at nine years. The policy could also reduce disparities, with the greatest estimated health gains among Black and Hispanic adults, and Americans with lower income and less education -- populations that consume the most sugar as a historical consequence of inequitable systems.

Product reformulation efforts have been shown to be successful in reducing other harmful nutrients, such as trans fats and sodium. The U.S., however, lags other countries in implementing strong sugar-reduction policies, with countries such as the UK, Norway, and Singapore taking the lead on sugar-reformulation efforts. The US may yet become a leader in protecting its people from the dangers of excessive sugar consumption if the NSSRI's proposed sugar-reduction targets are achieved. "The NSSRI policy is by far the most carefully designed and comprehensive, yet achievable, sugar-reformulation initiative in the world," says Shangguan.

Consuming sugary foods and beverages is strongly linked to obesity and diseases such as type 2 diabetes and cardiovascular disease, the leading cause of mortality in the U.S. More than two in five American adults are obese, one in two have diabetes or prediabetes, and nearly one in two have cardiovascular disease, with those from lower-income groups being disproportionately burdened.

"Sugar is one of the most obvious additives in the food supply to reduce to reasonable amounts," says Dariush Mozaffarian, MD, DrPH, co-senior author and dean of the Friedman School of Nutrition Science and Policy at Tufts University. "Our findings suggest it's time to implement a national program with voluntary sugar reduction targets, which can generate major improvements in health, health disparities, and healthcare spending in less than a decade."

https://www.sciencedaily.com/releases/2021/08/210827082431.htm

Pecan-enriched diet shown to reduce cholesterol

People at risk for cardiovascular disease showed improvements

August 23, 2021

Science Daily/University of Georgia

While the proper pronunciation of pecan remains a subject of debate, University of Georgia researchers have shown the tree nut can dramatically improve a person's cholesterol levels.

Participants at risk for cardiovascular disease who ate pecans during an eight-week intervention showed significant improvements in total cholesterol, triglycerides and low-density lipoprotein (LDL), or "bad" cholesterol, in a study conducted by researchers in the UGA College of Family and Consumer Sciences.

"This dietary intervention, when put in the context of different intervention studies, was extremely successful," said Jamie Cooper, a professor in the FACS department of nutritional sciences and one of the study's authors. "We had some people who actually went from having high cholesterol at the start of the study to no longer being in that category after the intervention."

Researchers saw an average drop of 5% in total cholesterol and between 6% and 9% in LDL among participants who consumed pecans.

For context, researchers referred to a previous meta-analysis of 51 exercise interventions designed to lower cholesterol that reported an average reduction of 1% in total cholesterol and 5% in LDL cholesterol.

"The addition of pecans to the diet not only produced a greater and more consistent reduction in total cholesterol and LDL compared to many other lifestyle interventions, but may also be a more sustainable approach for long-term health," Cooper said. "Some research shows that even a 1% reduction in LDL is associated with a small reduction of coronary artery disease risk, so these reductions are definitely clinically meaningful."

Researchers assigned 52 adults between the ages of 30 and 75 who were at higher risk for cardiovascular disease to one of three groups.

One group consumed 68 grams or about 470 calories of pecans a day as part of their regular diet; a second group substituted pecans for a similar amount of calories from their habitual diet, and a control group did not consume pecans.

At eight weeks, participants consumed a high-fat meal to determine changes in blood lipids and the amount of glucose, or sugar, in the blood.

Fasted blood lipids showed similar improvements among the two pecan groups while post-meal triglycerides were reduced in the group that added pecans. Post-meal glucose was lowered in the group that substituted pecans.

"Whether people added them or substituted other foods in the diet for them, we still saw improvements and pretty similar responses in total cholesterol and LDL cholesterol in particular," said Cooper, who also serves as director of the UGA Obesity Initiative.

Researchers pointed to the known bioactive properties of pecans for possible mechanisms driving the improvements.

Pecans are high in healthy fatty acids and fiber, both of which have been linked to lower cholesterol.

https://www.sciencedaily.com/releases/2021/08/210823125651.htm

Study links air pollution to nearly 6 million preterm births around the world

Data on indoor and outdoor pollution comes from all inhabited continents

September 28, 2021

Science Daily/University of California - San Francisco

Air pollution likely contributed to almost 6 million premature births and almost 3 million underweight babies in 2019, according to a UC San Francisco and University of Washington global burden of disease study and meta-analysis that quantifies the effects of indoor and outdoor pollution around the world.

The analysis, published September 28, 2021, in PLOS Medicine, is the most in-depth look yet at how air pollution affects several key indicators of pregnancy, including gestational age at birth, reduction in birth weight, low birth weight, and preterm birth. And it is the first global burden of disease study of these indicators to include the effects of indoor air pollution, mostly from cook stoves, which accounted for two-thirds of the measured effects.

A growing body of evidence points to air pollution as a major cause of preterm birth and low birthweight. Preterm birth is the leading cause of neonatal mortality worldwide, affecting more than 15 million infants every year. Children with low birthweight or who are born premature have higher rates of major illness throughout their lives.

The World Health Organization estimates that more than 90 percent of the world's population lives with polluted outdoor air, and half the global population is also exposed to indoor air pollution from burning coal, dung and wood inside the home.

"The air pollution-attributable burden is enormous, yet with sufficient effort, it could be largely mitigated," said lead author Rakesh Ghosh, PhD, a prevention and public health specialist at the Institute for Global Health Sciences at UCSF.

The analysis, which was conducted with researchers at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, quantified preterm birth and low birthweight risks based on total indoor and outdoor pollution exposure, while also accounting for the likelihood that the negative effects taper off at higher levels.

The study concluded that the global incidence of preterm birth and low birthweight could be reduced by almost 78 percent if air pollution were minimized in Southeast Asia and sub-Saharan Africa, where indoor pollution is common and preterm birth rates are the highest in the world.

But it also found significant risks from ambient air pollution in more developed parts of the world. In the United States, for example, outdoor air pollution is estimated to have contributed to almost 12,000 preterm births in 2019.

Previously, the same research team quantified the effects of air pollution on early life mortality, concluding that it contributed to the deaths of 500,000 newborns in 2019.

"With this new, global and more rigorously generated evidence, air pollution should now be considered a major driver of infant morbidity and mortality, not just of chronic adult diseases," Ghosh said. "Our study suggests that taking measures to mitigate climate change and reduce air pollution levels will have significant health co-benefit for newborns."

https://www.sciencedaily.com/releases/2021/09/210928141834.htm

Gut bacteria influence brain development

Researchers discover biomarkers that indicate early brain injury in extreme premature infants

Science Daily/September 3, 2021

University of Vienna

Extremely premature infants are at a high risk for brain damage. Researchers have now found possible targets for the early treatment of such damage outside the brain: Bacteria in the gut of premature infants may play a key role. The research team found that the overgrowth of the gastrointestinal tract with the bacterium Klebsiella is associated with an increased presence of certain immune cells and the development of neurological damage in premature babies.

Complex interplay: the gut-immune-brain axis

The early development of the gut, the brain and the immune system are closely interrelated. Researchers refer to this as the gut-immune-brain axis. Bacteria in the gut cooperate with the immune system, which in turn monitors gut microbes and develops appropriate responses to them. In addition, the gut is in contact with the brain via the vagus nerve as well as via the immune system. "We investigated the role this axis plays in the brain development of extreme preterm infants," says the first author of the study, David Seki. "The microorganisms of the gut microbiome -- which is a vital collection of hundreds of species of bacteria, fungi, viruses and other microbes -- are in equilibrium in healthy people. However, especially in premature babies, whose immune system and microbiome have not been able to develop fully, shifts are quite likely to occur. These shifts may result in negative effects on the brain," explains the microbiologist and immunologist.

Patterns in the microbiome provide clues to brain damage

"In fact, we have been able to identify certain patterns in the microbiome and immune response that are clearly linked to the progression and severity of brain injury," adds David Berry, microbiologist and head of the research group at the Centre for Microbiology and Environmental Systems Science (CMESS) at the University of Vienna as well as Operational Director of the Joint Microbiome Facility of the Medical University of Vienna and University of Vienna. "Crucially, such patterns often show up prior to changes in the brain. This suggests a critical time window during which brain damage of extremely premature infants may be prevented from worsening or even avoided."

Comprehensive study of the development of extremely premature infants

Starting points for the development of appropriate therapies are provided by the biomarkers that the interdisciplinary team was able to identify. "Our data show that excessive growth of the bacterium Klebsiella and the associated elevated ??-T-cell levels can apparently exacerbate brain damage," explains Lukas Wisgrill, Neonatologist from the Division of Neonatology, Pediatric Intensive Care Medicine and Neuropediatrics at the Department of Pediatric and Adolescent Medicine at the Medical University of Vienna. "We were able to track down these patterns because, for a very specific group of newborns, for the first time we explored in detail how the gut microbiome, the immune system and the brain develop and how they interact in this process," he adds. The study monitored a total of 60 premature infants, born before 28 weeks gestation and weighing less than 1 kilogram, for several weeks or even months. Using state-of-the-art methods -- the team examined the microbiome using 16S rRNA gene sequencing, among other methods -- the researchers analysed blood and stool samples, brain wave recordings (e.g. aEEG) and MRI images of the infants' brains.

Research continues with two studies

The study, which is an inter-university clusterproject under the joint leadership by Angelika Berger (Medical University of Vienna) and David Berry (University of Vienna), is the starting point for a research project that will investigate the microbiome and its significance for the neurological development of prematurely born children even more thoroughly. In addition, the researchers will continue to follow the children of the initial study. "How the children's motoric and cognitive skills develop only becomes apparent over several years," explains Angelika Berger. "We aim to understand how this very early development of the gut-immune-brain axis plays out in the long term. " The most important cooperation partners for the project are already on board: "The children's parents have supported us in the study with great interest and openness," says David Seki. "Ultimately, this is the only reason we were able to gain these important insights. We are very grateful for that."

https://www.sciencedaily.com/releases/2021/09/210903132656.htm

Children who eat more fruit and veggies have better mental health

September 28, 2021

Science Daily/University of East Anglia

Children who eat a better diet, packed with fruit and vegetables, have better mental wellbeing -- according to new research from the University of East Anglia.

A new study published today is the first to investigate the association between fruit and vegetable intakes, breakfast and lunch choices, and mental wellbeing in UK school children.

It shows how eating more fruit and veg is linked with better wellbeing among secondary school pupils in particular. And children who consumed five or more portions of fruit and veg a day had the highest scores for mental wellbeing.

The study was led by UEA Health and Social Care Partners in collaboration with Norfolk County Council.

The research team say that public health strategies and school policies should be developed to ensure that good quality nutrition is available to all children before and during school to optimise mental wellbeing and empower children to fulfil their full potential.

Lead researcher Prof Ailsa Welch, from UEA's Norwich Medical School, said: "We know that poor mental wellbeing is a major issue for young people and is likely to have long-term negative consequences.

"The pressures of social media and modern school culture have been touted as potential reasons for a rising prevalence of low mental wellbeing in children and young people.

"And there is a growing recognition of the importance of mental health and wellbeing in early life -- not least because adolescent mental health problems often persist into adulthood, leading to poorer life outcomes and achievement.

"While the links between nutrition and physical health are well understood, until now, not much has been known about whether nutrition plays a part in children's emotional wellbeing. So, we set out to investigate the association between dietary choices and mental wellbeing among schoolchildren."

The research team studied data from almost 9,000 children in 50 schools across Norfolk (7,570 secondary and 1,253 primary school children) taken from the Norfolk children and Young People's Health and wellbeing Survey.

This survey was commissioned by the Public Health department of Norfolk County Council and the Norfolk Safeguarding Children Board. It was open to all Norfolk schools during October 2017.

Children involved in the study self-reported their dietary choices and took part in age-appropriate tests of mental wellbeing that covered cheerfulness, relaxation, and having good interpersonal relationships.

Prof Welch said: "In terms of nutrition, we found that only around a quarter of secondary-school children and 28 per cent of primary-school children reported eating the recommended five-a-day fruits and vegetables. And just under one in ten children were not eating any fruits or vegetables.

"More than one in five secondary school children and one in 10 primary children didn't eat breakfast. And more than one in 10 secondary school children didn't eat lunch.

The team looked at the association between nutritional factors and mental wellbeing and took into account other factors that might have an impact -- such as adverse childhood experiences and home situations.

Dr Richard Hayhoe, also from UEA's Norwich Medical School, said: "We found that eating well was associated with better mental wellbeing in children. And that among secondary school children in particular, there was a really strong link between eating a nutritious diet, packed with fruit and vegetables, and having better mental wellbeing.

"We also found that the types of breakfast and lunch eaten by both primary and secondary school pupils were also significantly associated with wellbeing.

"Children who ate a traditional breakfast experienced better wellbeing than those who only had a snack or drink. But secondary school children who drank energy drinks for breakfast had particularly low mental wellbeing scores, even lower than for those children consuming no breakfast at all.

"According to our data, in a class of 30 secondary school pupils, around 21 will have consumed a conventional-type breakfast, and at least four will have had nothing to eat or drink before starting classes in the morning.

"Similarly, at least three pupils will go into afternoon classes without eating any lunch. This is of concern, and likely to affect not only academic performance at school but also physical growth and development.

"Another interesting thing that we found was that nutrition had as much or more of an impact on wellbeing as factors such as witnessing regular arguing or violence at home.

Prof Welch said: "As a potentially modifiable factor at an individual and societal level, nutrition represents an important public health target for strategies to address childhood mental wellbeing.

"Public health strategies and school policies should be developed to ensure that good quality nutrition is available to all children both before and during school in order to optimise mental wellbeing and empower children to fulfil their full potential."

https://www.sciencedaily.com/releases/2021/09/210928075004.htm

Study finds body mass index for children greatest in Midwest, least in West

September 1, 2021

Science Daily/University of Colorado Anschutz Medical Campus

A study examining the body mass index (BMI) of over 14,000 children from birth to age 15 shows those in the Midwest have the highest BMI levels while kids in the West have the lowest, suggesting regional influences may play a role in the development of childhood obesity.

The study, published today in the journal Obesity, also showed a higher birthweight and lower levels of formal education among mothers was associated with higher BMI in children. Black and Hispanic children had a higher BMI than non-Hispanic white children in some, but not all, parts of the country.

"We know that home and school environments are important drivers of children's nutritional status," said the study's lead author Traci Bekelman, PhD, MPH, a research assistant professor in the Lifecourse Epidemiology of Adiposity and Diabetes (LEAD) Center at the Colorado School of Public Health at CU Anschutz. "But we don't know as much about regional influences."

Obesity is a persistent problem in adults and increasingly in children. At least 35% of children are overweight or suffer from obesity. Interventions often fail so investigators in this study wanted to see if regional differenchttps://www.sciencedaily.com/releases/2021/09/210903132656.htmes could account for varying BMI levels.

"If we know the factors that affect children's body size, we can help prevent them from becoming overweight or obese," said the study's senior author Dana Dabelea, MD, PhD, professor of pediatrics and epidemiology at the Colorado School of Public Health and director of the LEAD Center. "This study looked at factors related to children's body size, like where children live, how much they weighed at birth, and their ethnic background."

The study population was drawn from the Environmental influences on Child Health Outcomes (ECHO) Program. ECHO investigates the effects of environmental exposures on child health. In this study, that included a large sample of children from 25 community and clinic-based cohorts with longitudinal data across the US.

Researchers studied the Northeast, Midwest, South and the West. Children of differing racial groups were included and about half were girls. They measured children's height and weight between the years 2000 and 2018, then calculated BMI based on this data. The researchers also had information on race, ethnicity, neighborhood and the mother's level of education.

Overall, they found that children in the Midwest had the highest BMI followed by the Northeast, the South and the West. These differences mostly remained even after researchers took into consideration the type of people living in each region.

Bekelman said the features of the environment in each area could impact BMI. She said the team was surprised that they only found racial and ethnic differences in BMI in certain areas.

"This finding and future studies could help researchers understand the causes of health disparities," she said.

According to the study, the connection between geographical regions and BMI are not well understood, especially BMI in children. Adult data show diet quality and time doing moderate-to-vigorous exercise are higher in the West and Northeast compared to the South and Midwest, suggesting lifestyle behaviors play a role. But other studies show no regional variation in physical activity.

Then there are environmental factors including density of fast food restaurants, supermarkets and recreation facilities that have all been linked to childhood BMI. State and regional regulations for the kinds of food and drinks offered at schools and in childcare also vary widely and have been linked to BMI. But there is little evidence of regional variation.

The findings set the stage for additional studies to determine why BMI varies from place to place.

"For example, researchers could study whether children's eating habits and their physical activity levels also vary based on the area they live in," Bekelman said. "Another next step is to find out why there are racial and ethnic differences in BMI in some areas but not others."

Understanding regional influences on BMI, she said, may boost efforts to head off health disparities among populations.

https://www.sciencedaily.com/releases/2021/09/210901142710.htm

Breast milk proven to enhance heart performance in premature babies

August 30, 2021

Science Daily/RCSI

New research from RCSI University of Medicine and Health Sciences demonstrates the beneficial effect of breast milk consumption on cardiovascular health and early cardiovascular development in premature infants.

Published in JAMA Network Open, the study of 80 preterm infants is the first of its kind to show that preterm infants with higher exposure their mother's own milk had enhanced cardiac function at age one year, with values approaching those of healthy full-term infants.

The research was led by Professor Afif EL-Khuffash, Clinical Professor of Paediatrics at RCSI and Consultant Neonatologist at the Rotunda Hospital, Dublin, in collaboration with researchers at University of Oxford; Mount Sinai Hospital, Toronto; Northwestern University Feinberg School of Medicine; Washington University School of Medicine; and, Harvard Medical School.

Children and adults who are born preterm are at increased risk of cardiovascular disorders, including ischemic heart disease, heart failure, systemic and pulmonary hypertension, and are more likely to die as a result of cardiovascular disease. The hearts of young people born early are known to have unique traits such as reduced biventricular volume, shorter length, lower systolic and diastolic function and a disproportionate increase in muscle mass. This results in impaired heart function, which is significantly lower than that of healthy infants who are born at term. This dysfunction is detectable at hospital discharge and persists throughout their adolescence.

This study shows that exclusive breast milk consumption in the first months after birth is associated with a normalisation of some of these traits. Premature infants exposed to a high proportion of their mother's own milk during the first few week after delivery had greater left and right heart function and structure with lower lung pressures and enhanced right heart response to stress at one year of age compared to preterm infants who had a higher intake of formula, with all measures approaching those seen in term-born healthy children.

These findings were apparent before discharge from the hospital and persisted up to a year of age (the duration of follow up).

Professor EL-Khuffash said: "This study provides the first evidence of an association between early postnatal nutrition in preterm-born infants and heart function over the first year of age, and adds to the already known benefits of breast milk for infants born prematurely."

"Preterm infants have abnormal heart function. However, those who are fed their mother's own milk demonstrate recovery of their heart function to levels comparable to healthy term born infants. Preterm infants fed formula do not demonstrate this recovery."

https://www.sciencedaily.com/releases/2021/08/210830140234.htm