Moderate egg consumption not associated with higher cardiovascular disease risk

March 5, 2020

Science Daily/Harvard T.H. Chan School of Public Health

Consuming up to one egg per day does not appear to be associated with cardiovascular disease (CVD) risk, according to a new study and meta-analysis led by researchers at Harvard T.H. Chan School of Public Health.

"Recent studies reignited the debate on this controversial topic, but our study provides compelling evidence supporting the lack of an appreciable association between moderate egg consumption and cardiovascular disease," said first author Jean-Philippe Drouin-Chartier, visiting scientist in the Department of Nutrition and assistant professor at Laval University in Québec, Canada. The study will be published online March 4, 2020 in the BMJ.

The relationship between egg consumption and CVD risk has been a topic of intense debate in the scientific community in recent decades. Just in the past 12 months, three published studies have reported conflicting results.

The new findings update a 1999 study -- the first major analysis of eggs and cardiovascular disease -- that found no association between eggs and CVD risk. That study was led by Frank Hu, Fredrick J. Stare Professor of Nutrition and Epidemiology, chair of the Department of Nutrition, and a co-author of the current study.

For this study, researchers analyzed health data from 173,563 women and 90,214 men participating in the Nurses' Health Study (NHS) I and II, and the Health Professionals Follow-Up Study (HPFS) who were free of CVD, type 2 diabetes, and cancer at baseline. They used repeated measures of diet during up to 32 years of follow-up to gain a detailed picture of potentially confounding lifestyle factors such as high body mass index and red meat consumption. The researchers also conducted the largest meta-analysis of this topic, including 28 prospective cohort studies with up to 1.7 million participants.

The analysis of NHS and HPFS participants found no association between moderate egg consumption and risk of CVD. Results from the meta-analysis supported this finding in U.S. and European populations; however, some evidence suggested that moderate egg consumption may be associated with lower CVD risk in Asian populations although this may be confounded by the overall dietary pattern.

Study co-author Shilpa Bhupathiraju, research scientist in the Harvard Chan School Department of Nutrition and associate epidemiologist at Brigham and Women's Hospital, said that while moderate egg consumption can be part of a healthy eating pattern, it is not essential. "There is a range of other foods that can be included in a healthy breakfast, such as whole grain toasts, plain yogurt, and fruits."

https://www.sciencedaily.com/releases/2020/03/200305002842.htm

When should you eat to manage your weight? Breakfast, not late-night snacks

February 28, 2020

Science Daily/PLOS

The balance between weight gain and weight gain loss is predominantly determined by what you eat, how much you eat, and by how much exercise you get. But another important factor is often neglected... Published February 27 in the open-access journal PLOS Biology, research conducted by Kevin Kelly, Owen McGuinness, Carl Johnson and colleagues of Vanderbilt University, USA shows that it's not just how many calories you eat, but WHEN you eat them that will determine how well you burn those calories.

Your daily biological clock and sleep regulate how the food you eat is metabolized; thus the choice of burning fats or carbohydrates changes depending on the time of day or night. Your body's circadian rhythm has programmed your body to burn fat when you sleep, so when you skip breakfast and then snack at night you delay burning the fat.

The researchers monitored the metabolism of mid-aged and older subjects in a whole-room respiratory chamber over two separate 56-hour sessions, using a "random crossover" experimental design. In each session, lunch and dinner were presented at the same times (12:30 and 17:45, respectively), but the timing of the third meal differed between the two halves of the study. Thus in one of the 56-hour bouts, the additional daily meal was presented as breakfast (8:00) whereas in the other session, a nutritionally equivalent meal was presented to the same subjects as a late-evening snack (22:00). The duration of the overnight fast was the same for both sessions.

Whereas the two sessions did not differ in the amount or type of food eaten or in the subjects' activity levels, the daily timing of nutrient availability, coupled with clock/sleep control of metabolism, flipped a switch in the subjects' fat/carbohydrate preference such that the late-evening snack session resulted in less fat burned when compared to the breakfast session. The timing of meals during the day/night cycle therefore affects the extent to which ingested food is used versus stored.

This study has important implications for eating habits, suggesting that a daily fast between the evening meal and breakfast will optimize weight management.

https://www.sciencedaily.com/releases/2020/02/200228125230.htm

Can't sleep? Prebiotics could help

Dietary compounds found to influence gut metabolites, buffering stress

March 3, 2020

Science Daily/University of Colorado at Boulder

New research shows that animals on a prebiotic diet sleep better and are buffered from the physiological impacts of stress. The undigestible dietary compounds, found in fibrous foods and some dairy products, serve as nourishment for beneficial bacteria and influence metabolites that, in turn, impact the brain.

Specific fibers known as prebiotics can improve sleep and boost stress resilience by influencing gut bacteria and the potent biologically active molecules, or metabolites, they produce, new University of Colorado Boulder research shows.

The research could ultimately lead to new approaches to treating sleep problems, which affect 70 million Americans.

"The biggest takeaway here is that this type of fiber is not just there to bulk up the stool and pass through the digestive system," said Robert Thompson, a postdoctoral researcher in the Department of Integrative Physiology and lead author of the study, published today in the journal Scientific Reports. "It is feeding the bugs that live in our gut and creating a symbiotic relationship with us that has powerful effects on our brain and behavior."

Food for our bugs

Most people are familiar with probiotics, friendly bacteria present in fermented foods like yogurt and sauerkraut. More recently, scientists have taken an interest in prebiotics -- dietary compounds that humans cannot digest but serve as nourishment for our microbiome, or the trillions of bacteria residing within us. While not all fibers are prebiotics, many fibrous foods like leeks, artichokes, onions and certain whole grains are rich in them.

For the study, the researchers started adolescent male rats on either standard chow or chow infused with prebiotics and tracked an array of physiological measures before and after the rats were stressed.

As reported in the researchers' previous study, those on the prebiotic diet spent more time in restorative non-rapid-eye-movement (NREM) sleep. After stress, they also spent more time in rapid-eye-movement (REM) sleep, which is believed to be critical for recovery from stress.

While rats eating standard chow saw an unhealthy flattening of the body's natural temperature fluctuations and a drop in healthy diversity of their gut microbiome after stress, those fed prebiotics were buffered from these effects.

The new study sheds light on how prebiotics can help bust stress.

"We know that this combination of dietary fibers helps promote stress robustness and good sleep and protects the gut microbiome from disruption. With this new study, we wanted to try to identify the signal," said senior author and Integrative Physiology Professor Monika Fleshner, director of the Stress Physiology Laboratory.

Using a technology called mass spectrometry to analyze the rats' fecal samples, the researchers measured metabolites, or bioactive small molecules produced by bacteria as food is broken down.

They found rats on the prebiotic diet had a substantially different "metabolome," or make-up of metabolites. Theirs was higher in dozens of them, including fatty acids, sugars and steroids which may, via gut-brain signaling pathways, influence behavior. The rats' metabolome also looked different after stress.

For instance, the rats on the standard chow diet saw dramatic spikes in allopregnanolone precursor and Ketone Steroid, potentially sleep-disrupting metabolites, while those on the prebiotic diet saw no such spike.

"Our results reveal novel signals that come from gut microbes that may modulate stress physiology and sleep," said Fleshner.

In search of a better sleeping pill

While prebiotic dietary fiber is certainly healthy, it's uncertain whether just loading up on foods rich in it can promote sleep. The rats were fed very high doses of four specific prebiotics, including: galactooligosaccharides, which are present in lentils and cabbage; polydextrose (PDX) an FDA-approved food additive often used as a sweetener; lactoferrin, found in breast milk; and milk fat globular protein, abundant in dairy products.

"You'd probably have to eat a whole lot of lentils and cabbage to see any effect," said Thompson.

Prebiotic supplements already abound on natural food store shelves. But Fleshner said it's too soon to say whether a supplement or drug containing such compounds would be safe and effective for everyone. Depending on what their microbial make-up is, different people might respond differently.

"These are powerful molecules with real neuroactive effects and people need to exercise some caution," she said.

Human studies are already in the works at CU Boulder.

Ultimately, Fleshner believes what they are learning in her lab could lead to a new class of options for people who can't sleep but don't like taking narcotics.

"Armed with this information, we might be able to develop a targeted therapeutic that boosts the molecules that buffer against stress and tamps down the ones that seem to disrupt sleep," she said. "It's exciting to think about."

https://www.sciencedaily.com/releases/2020/03/200303155658.htm

A blood factor involved in weight loss and aging

October 22, 2019

Science Daily/Institut Pasteur

Aging can be delayed through lifestyle changes (physical exercise, restricting calorie intake, etc.). Researchers have elucidated the properties of a molecule in the blood - GDF11 - whose mechanisms were previously unknown. In a mouse model, they showed that this molecule could mimic the benefits of certain calorie restrictions - dietary regimens that have proven their efficacy in reducing cardiovascular disease, preventing cancer and increasing neurogenesis in the brain.

Aging is a process that affects all functions of the human body, particularly brain function. However, aging can be delayed through lifestyle changes (physical exercise, restricting calorie intake, etc.). Researchers at the Institut Pasteur and CNRS have elucidated the properties of a molecule in the blood -- GDF11 -- whose mechanisms were previously unknown. In a mouse model, they showed that this molecule could mimic the benefits of certain calorie restrictions -- dietary regimens that have proven their efficacy in reducing cardiovascular disease, preventing cancer and increasing neurogenesis in the brain. The results of this research were published in the journal Aging Cell on October 22, 2019.

Today it is possible to maintain a healthy brain in the long term. For the past 30 years, it has been generally acknowledged that certain diet restrictions such as intermittent fasting can improve cognitive performance and extend life expectancy in several species. It has also been proven that calorie restriction (a reduction in calorie intake of 20% to 30% while preserving nutritional quality) reduces the risk of cardiovascular disease and cancer, while increasing production of new neurons in the brain.

In a previous study using mouse models, scientists observed that injecting aged mice with blood from young mice rejuvenated blood vessels in the brain, and consequently improved cerebral blood flow, while increasing neurogenesis and cognition . Scientists in the Perception and Memory Unit (Institut Pasteur/CNRS) put forward the theory that, since calorie restriction and supplementation with young blood were effective in rejuvenating organs, they most likely have certain mechanisms in common.

They therefore examined the molecule GDF11, which belongs to the GDF (Growth Differentiation Factor) protein family and is involved in embryonic development. GDF11 was already known to scientists for its ability to rejuvenate the aged brain. "By injecting this molecule into aged mouse models, we noticed an increase in neurogenesis and blood vessel remodeling," explains Lida Katsimpardi, a scientist in the Perception and Memory Unit and lead author of the study. The scientists also observed that the mice administered with GDF11 had lost weight without changing their appetite. This observation led them to believe that GDF11 could be a link between calorie restriction and the regenerating effects of young blood.

The next step was to confirm this theory by studying adiponectin, a hormone secreted by adipose tissue which induces weight loss without affecting appetite. In animals that have undergone calorie restriction, the blood levels of this hormone are high. "In animals that were administered GDF11, we also observed high levels of adiponectin," emphasizes Lida Katsimpardi, "and this shows that GDF11 causes metabolic changes similar to those induced by calorie restriction."

Until recently, there has been controversy over the role of GDF11 in aging, and its mechanisms were largely unknown. The findings of this study show that by inducing phenomena similar to those reported for calorie restriction leading to the stimulation of adiponectin and neurogenesis, GDF11 contributes to the birth of new neurons in the brain. "These findings are encouraging and support therapeutic uses of GDF11 in certain metabolic diseases, such as obesity, and neurodegenerative diseases," concludes Pierre-Marie Lledo, CNRS researcher, Head of the Institut Pasteur's Perception and Memory Unit and last author of the study.

https://www.sciencedaily.com/releases/2019/10/191022104858.htm

Eating a vegetarian diet rich in nuts, vegetables, soy linked to lower stroke risk

February 28, 2020

Science Daily/American Academy of Neurology

People who eat a vegetarian diet rich in nuts, vegetables and soy may have a lower risk of stroke than people who eat a diet that includes meat and fish, according to a study published in the February 26, 2020, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"Stroke is the second most common cause of death worldwide and a leading cause of disability," said study author Chin-Lon Lin, M.D., of Tzu Chi University in Hualien, Taiwan. "Stroke can also contribute to dementia. If we could reduce the number of strokes by people making changes to their diets, that would have a major impact on overall public health."

The study involved two groups of people from Buddhist communities in Taiwan where a vegetarian diet is encouraged, and smoking and drinking alcohol are discouraged. Approximately 30% of participants in both groups were vegetarians. Of the vegetarians, 25% were men. Researchers defined vegetarians as people who did not eat any meat or fish.

At the start of the study, the average age of all participants was 50 and none had experienced stroke. The first group of 5,050 people was followed for an average of six years. The second group of 8,302 people was followed for an average of nine years. Participants were given medical exams at the start of the study and asked about their diet.

Vegetarians ate more nuts, vegetables and soy than non-vegetarians and consumed less dairy. Both groups consumed the same amount of eggs and fruit. Vegetarians ate more fiber and plant protein. They also ate less animal protein and fat.

Researchers then looked at a national database to determine the numbers of strokes participants had during the course of the study.

In the first group of 5,050 people, there were 54 strokes. For ischemic strokes, which are strokes when blood flow to part of the brain is blocked, there were three strokes among 1,424 vegetarians, or 0.21%, compared to 28 strokes among 3,626 non-vegetarians, or 0.77%. After adjusting for age, sex, smoking and health conditions like high blood pressure and diabetes, researchers found vegetarians in this group had a 74% lower risk of ischemic stroke than non-vegetarians.

In the second group of 8,302 people, there were 121 strokes. For both ischemic and hemorrhagic strokes, also called bleeding strokes, there were 24 strokes among 2,719 vegetarians, or 0.88%, compared to 97 strokes among 5,583 non-vegetarians, or 1.73%. After adjusting for other factors, researchers found vegetarians in this group had a 48% lower risk of overall stroke than non-vegetarians, a 60% lower risk of ischemic stroke and a 65% lower risk of hemorrhagic stroke.

"Overall, our study found that a vegetarian diet was beneficial and reduced the risk of ischemic stroke even after adjusting for known risk factors like blood pressure, blood glucose levels and fats in the blood," said Lin. "This could mean that perhaps there is some other protective mechanism that may protecting those who eat a vegetarian diet from stroke."

One limitation of the study was that the diet of participants was only assessed at the start of the study, so it is not known if participants' diets changed over time. Another limitation was that study participants did not drink or smoke, so results may not reflect the general population. Also, results from the study population in Taiwan may not be generalizable worldwide. Finally, there could be other factors, not accounted for, that might affect stroke risk.

https://www.sciencedaily.com/releases/2020/02/200228102225.htm

How caloric restriction prevents negative effects of aging in cells

How caloric restriction prevents negative effects of aging in cells

February 27, 2020

Science Daily/Salk Institute

A new study provides the most detailed report to date of the cellular effects of a calorie-restricted diet in rats. While the benefits of caloric restriction have long been known, the new results show how this restriction can protect against aging in cellular pathways.

If you want to reduce levels of inflammation throughout your body, delay the onset of age-related diseases, and live longer, eat less food. That's the conclusion of a new study by scientists from the US and China that provides the most detailed report to date of the cellular effects of a calorie-restricted diet in rats. While the benefits of caloric restriction have long been known, the new results show how this restriction can protect against aging in cellular pathways, as detailed in Cell on February 27, 2020.

"We already knew that calorie restriction increases life span, but now we've shown all the changes that occur at a single-cell level to cause that," says Juan Carlos Izpisua Belmonte, a senior author of the new paper, professor in Salk's Gene Expression Laboratory and holder of the Roger Guillemin Chair. "This gives us targets that we may eventually be able to act on with drugs to treat aging in humans."

Aging is the highest risk factor for many human diseases, including cancer, dementia, diabetes and metabolic syndrome. Caloric restriction has been shown in animal models to be one of the most effective interventions against these age-related diseases. And although researchers know that individual cells undergo many changes as an organism ages, they have not known how caloric restriction might influence these changes.

In the new paper, Belmonte and his collaborators -- including three alumni of his Salk lab who are now professors running their own research programs in China -- compared rats who ate 30 percent fewer calories with rats on normal diets. The animals' diets were controlled from age 18 months through 27 months. (In humans, this would be roughly equivalent to someone following a calorie-restricted diet from age 50 through 70.)

At both the start and the conclusion of the diet, Belmonte's team isolated and analyzed a total of 168,703 cells from 40 cell types in the 56 rats. The cells came from fat tissues, liver, kidney, aorta, skin, bone marrow, brain and muscle. In each isolated cell, the researchers used single-cell genetic-sequencing technology to measure the activity levels of genes. They also looked at the overall composition of cell types within any given tissue. Then, they compared old and young mice on each diet.

Many of the changes that occurred as rats on the normal diet grew older didn't occur in rats on a restricted diet; even in old age, many of the tissues and cells of animals on the diet closely resembled those of young rats. Overall, 57 percent of the age-related changes in cell composition seen in the tissues of rats on a normal diet were not present in the rats on the calorie restricted diet.

"This approach not only told us the effect of calorie restriction on these cell types, but also provided the most complete and detailed study of what happens at a single-cell level during aging," says co-corresponding author Guang-Hui Liu, a professor at the Chinese Academy of Sciences.

Some of the cells and genes most affected by the diet related to immunity, inflammation and lipid metabolism. The number of immune cells in nearly every tissue studied dramatically increased as control rats aged but was not affected by age in rats with restricted calories. In brown adipose tissue -- one type of fat tissue -- a calorie-restricted diet reverted the expression levels of many anti-inflammatory genes to those seen in young animals.

"The primary discovery in the current study is that the increase in the inflammatory response during aging could be systematically repressed by caloric restriction" says co-corresponding author Jing Qu, also a professor at the Chinese Academy of Sciences.

When the researchers homed in on transcription factors -- essentially master switches that can broadly alter the activity of many other genes -- that were altered by caloric restriction, one stood out. Levels of the transcription factor Ybx1 were altered by the diet in 23 different cell types. The scientists believe Ybx1 may be an age-related transcription factor and are planning more research into its effects.

"People say that 'you are what you eat,' and we're finding that to be true in lots of ways," says Concepcion Rodriguez Esteban, another of the paper's authors and a staff researcher at Salk. "The state of your cells as you age clearly depends on your interactions with your environment, which includes what and how much you eat."

The team is now trying to utilize this information in an effort to discover aging drug targets and implement strategies towards increasing life and health span.

https://www.sciencedaily.com/releases/2020/02/200227144259.htm

Drinks with added sugars linked to lipid imbalance, which increases CVD risk

February 26, 2020

Science Daily/American Heart Association

Drinking 12 ounces of sugary drinks more than once per day is linked to lower levels of high-density lipoprotein cholesterol (HDL-C), ("good" cholesterol), and higher levels of triglycerides, in middle aged and older adults, both of which have been shown to increase risk of cardiovascular disease. These results are from a new observational study published today in the Journal of the American Heart Association, the open access journal of the American Heart Association.

In previous studies, added sugars have been shown to increase cardiovascular disease risk. Beverages such as sodas, sports drinks and fruit-flavored drinks are the largest source of added sugars for Americans.

"For some time, we have known sugary drinks can have a negative effect on Americans' health status, yet the assumption for many is that they only contribute to weight gain," said Eduardo Sanchez, M.D., M.P.H., chief medical officer for prevention and chief of the Center for Health Metrics and Evaluation at the American Heart Association. "This research reinforces our understanding of the potential negative impact sugary drinks have on blood cholesterol, which increases heart disease risk. It is yet one more reason for all of us to cut back on sodas and other sugar-sweetened beverages."

Researchers hypothesized that dyslipidemia could be one pathway by which sugary drinks may increase cardiovascular disease risk. An estimated 40% to 50% of U.S. adults are affected by dyslipidemia, an unhealthy imbalance of cholesterol and triglyceride levels in the blood, which increases the risk of cardiovascular disease.

To determine the association between sugary drinks on triglyceride and cholesterol levels, researchers studied observational medical data of up to 5,924 participants from the Offspring and Generation 3 cohorts of the Framingham Heart Study, who were followed for an average of 12.5 years between 1991 and 2014. The Offspring cohort of the Framingham Heart Study includes the children of original participants in the Framingham Heart Study, and the Generation 3 cohort includes grandchildren of the original participants in the Framingham Heart Study.

For this study, the beverages were defined as: 12 ounces of sugary drinks, such as sodas, fruit-flavored drinks, sports drinks, presweetened coffees and teas; 12 ounces of low-calorie sweetened beverages, including naturally and artificially sweetened "diet" sodas or other flavored drinks; or 8 ounces of 100% fruit juices, including orange, apple, grapefruit and other juices derived from whole fruits with no added sugars. Study participants were classified into five groups according to how often they drank the different beverage types ranging from low intake (<1 serving per month) to high intake (>1 serving per day).

Researchers analyzed how the different drink types and their consumption levels correlated with changes in cholesterol and triglyceride levels over approximately four-year periods. They found that:

• Drinking sugar-sweetened beverages (more than 12 ounces per day) was associated with a 53% higher incidence of high triglycerides and a 98% higher incidence of low HDL cholesterol (the "good" cholesterol) compared to those who drank less than one serving per month;

• Drinking low-calorie sweetened beverages did not appear to be associated with increased dyslipidemia risk among the people who regularly drank low-calorie sweetened beverages; and

• Regularly drinking up to 12 ounces of 100% fruit juice per day was not associated with adverse changes in cholesterol or dyslipidemia, though further research is needed to warrant this finding.

"Reducing the number of or eliminating sugary drink consumption may be one strategy that could help people keep their triglyceride and HDL cholesterol at healthier levels," said lead study author Nicola McKeown, Ph.D., a nutrition epidemiologist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston. "And, while our study didn't find negative consequences on blood lipids from drinking low-calorie sweetened drinks, there may be health consequences of consuming these beverages on other risk factors. Water remains the preferred and healthiest beverage."

While previous cross-sectional studies have had similar findings, this study reaffirms those findings with prospective data. One potential limitation of the study is that participants self-reported their dietary intake.

The American Heart Association recommends people eliminate sugary drink consumption to improve heart health and to reduce the risk of cardiovascular disease.

The National Institutes of Health, the American Heart Association and the U.S. Department of Agriculture's Agricultural Research Service supported the study.

https://www.sciencedaily.com/releases/2020/02/200226072110.htm

Weight-based bullying linked to increased adolescent alcohol, marijuana use

Overweight girls most likely to report being bullied, study finds

February 25, 2020

Science Daily/American Psychological Association

Adolescents who are bullied about their weight or body shape may be more likely to use alcohol or marijuana than those who are not bullied, according to new research published by the American Psychological Association.

The link between appearance-related teasing and substance use was strongest among overweight girls, raising special concerns about this group.

"This type of bullying is incredibly common and has many negative effects for adolescents," said lead study author Melanie Klinck, BA, a clinical research assistant at the University of Connecticut. "The combination of appearance-related teasing and the increased sensitivity to body image during adolescence may create a heightened risk for substance use."

"These findings raise larger issues about how society places too much emphasis on beauty and body image for girls and women and the damaging effects that may result," said Christine McCauley Ohannessian, PhD, professor of pediatrics and psychiatry at the University of Connecticut School of Medicine, as well as director of the Center for Behavioral Health at Connecticut Children's Medical Center and a study co-author.

"Schools and communities should specifically address appearance-related teasing in anti-bullying policies and substance-use interventions," she said. "Parents particularly have a role to play in addressing this issue. There is some startling research showing that some of the most hurtful examples of weight-based teasing come from parents or siblings, so families should be kind when they discuss the weight of their children."

The study, which was conducted at Connecticut Children's Medical Center, involved a survey of 1,344 students ages 11 to 14 from five public middle schools near Hartford, Connecticut. The students were asked if siblings, parents or peers had teased them about their weight, body shape or eating during the prior six months. More than half (55%) of the overall participants reported weight-based teasing, including three out of four overweight girls (76%), 71% of overweight boys, 52% of girls who weren't overweight, and 43% of boys who weren't overweight.

The participants also were asked about their alcohol and marijuana use. The results showed that frequent weight-based teasing was associated with higher levels of total alcohol use, binge drinking and marijuana use. In a follow-up survey six months later, weight-based teasing was still linked to total alcohol use and binge drinking. The research was published online in Psychology of Addictive Behaviors.

Previous research has found that boys have greater substance use in their teens and early adulthood, but girls begin using alcohol and drugs at an earlier age compared with boys. Those trends may be related to the societal pressures for girls to adhere to unrealistic body image ideals. This can damage their sense of self-worth and contribute to eating disorders and self-medication through substance use to cope with teasing or fit in with their peers, Klinck said.

"The old saying that 'sticks and stones may break my bones but words will never hurt me' is a fallacy that ignores the serious effects of emotional abuse and verbal bullying," Klinck said. "Weight-based discrimination appears to be one of the most common and seemingly socially sanctioned reasons to bully or discriminate against someone. As a society, we need to address the damage caused by this, especially for girls."

https://www.sciencedaily.com/releases/2020/02/200225154338.htm

The effects of obesity mirror those of aging

Researchers identify a shared list of health issues, from DNA damage to cognitive decline

February 25, 2020

Science Daily/Concordia University

Researchers argue that obesity should be considered premature aging. They look at how obesity predisposes people to acquiring the kinds of potentially life-altering or life-threatening diseases normally seen in older individuals: compromised genomes, weakened immune systems, decreased cognition, increased chances of developing type 2 diabetes, Alzheimer's disease, cardiovascular disease, cancer and other illnesses.

Globally, an estimated 1.9 billion adults and 380 million children are overweight or obese. According to the World Health Organization, more people are dying from being overweight than underweight. Researchers at Concordia are urging health authorities to rethink their approach to obesity.

In their paper published in the journal Obesity Reviews, the researchers argue that obesity should be considered premature aging. They look at how obesity predisposes people to acquiring the kinds of potentially life-altering or life-threatening diseases normally seen in older individuals: compromised genomes, weakened immune systems, decreased cognition, increased chances of developing type 2 diabetes, Alzheimer's disease, cardiovascular disease, cancer and other illnesses.

The study was led by Sylvia Santosa, associate professor of health, kinesiology and applied physiology in the Faculty of Arts and Science. She and her colleagues reviewed more than 200 papers that looked at obesity's effects, from the level of the cell to tissue to the entire body. The study was co-authored by Bjorn Tam, Horizon postdoctoral fellow, and José Morais, an associate professor in the Department of Medicine at McGill University.

"We are trying to comprehensively make the argument that obesity parallels aging," explains Santosa, a Tier II Canada Research Chair in Clinical Nutrition. "Indeed, the mechanisms by which the comorbidities of obesity and aging develop are very similar."

From cells to systems

The paper looks at ways obesity ages the body from several different perspectives. Many previous studies have already linked obesity to premature death. But the researchers note that at the lowest levels inside the human body, obesity is a factor that directly accelerates the mechanisms of aging.

For instance, Santosa and her colleagues look at the processes of cell death and the maintenance of healthy cells -- apoptosis and autophagy, respectively -- that are usually associated with aging.

Studies have shown that obesity-induced apoptosis has been seen in mice hearts, livers, kidneys, neurons, inner ears and retinas. Obesity also inhibits autophagy, which can lead to cancer, cardiovascular disease, type 2 diabetes and Alzheimer's.

At the genetic level, the researchers write that obesity influences a number of alterations associated with aging. These include the shortening of protective caps found on the ends of chromosomes, called telomeres. Telomeres in patients with obesity can be more than 25 per cent shorter than those seen in control patients, for instance.

Santosa and her colleagues further point out that obesity's effects on cognitive decline, mobility, hypertension and stress are all similar to those of aging.

Pulling out from the cellular level, the researchers say obesity plays a significant role in the body's fight against age-related diseases. Obesity, they write, speeds up the aging of the immune system by targeting different immune cells, and that later weight reduction will not always reverse the process.

The effects of obesity on the immune system, in turn, affect susceptibility to diseases like influenza, which often affects patients with obesity at a higher rate than normal-weight individuals. They are also at higher risk of sarcopenia, a disease usually associated with aging that features a progressive decline in muscle mass and strength.

Finally, the paper spells out how individuals with obesity are more susceptible to diseases closely associated with later-life onset, such as type 2 diabetes, Alzheimer's and various forms of cancer.

Similarities too big to ignore

Santosa says the inspiration for this study came to her when she realized how many children with obesity were developing adult-onset conditions of diseases, such as hypertension, high cholesterol and type 2 diabetes. She also realized that the comorbidities of obesity were similar to that of aging.

"I ask people to list as many comorbidities of obesity as they can," Santosa says. "Then I ask how many of those comorbidities are associated with aging. Most people will say, all of them. There is certainly something that is happening in obesity that is accelerating our aging process.'"

She thinks this research will help people better understand how obesity works and stimulate ideas on how to treat it.

"I'm hoping that these observations will focus our approach to understanding obesity a little more, and at the same time allow us to think of obesity in different ways. We're asking different types of questions than that which have traditionally been asked."

https://www.sciencedaily.com/releases/2020/02/200225122954.htm

Losing tongue fat improves sleep apnea

Tongue could be a new target for treating the common sleep disorder

January 10, 2020

Science Daily/University of Pennsylvania School of Medicine

Using magnetic resonance imaging (MRI) to measure the effect of weight loss on the upper airway in obese patients, researchers found that reducing tongue fat is a primary factor in lessening the severity of OSA.

Losing weight is an effective treatment for Obstructive Sleep Apnea (OSA), but why exactly this is the case has remained unclear. Now, researchers in the Perelman School of Medicine at the University of Pennsylvania have discovered that improvements in sleep apnea symptoms appear to be linked to the reduction of fat in one unexpected body part -- the tongue.

Using magnetic resonance imaging (MRI) to measure the effect of weight loss on the upper airway in obese patients, researchers found that reducing tongue fat is a primary factor in lessening the severity of OSA. The findings were published today in the American Journal of Respiratory and Critical Care Medicine.

"Most clinicians, and even experts in the sleep apnea world, have not typically focused on fat in the tongue for treating sleep apnea," said Richard Schwab, MD, chief of Sleep Medicine. "Now that we know tongue fat is a risk factor and that sleep apnea improves when tongue fat is reduced, we have established a unique therapeutic target that we've never had before."

Twenty-two million Americans suffer from sleep apnea, a serious health condition in which breathing repeatedly stops and starts, causing patients to wake up randomly throughout their sleep cycles. The condition, which is usually marked by loud snoring, can increase your risk for high blood pressure and stroke. While obesity is the primary risk factor for developing sleep apnea, there are other causes, such as having large tonsils or a recessed jaw. CPAP (continuous positive airway pressure) machines improves sleep apnea in about 75 percent of patients, studies suggest, but for the other 25 percent -- those who may have trouble tolerating the machine -- alternative treatment options, such as oral appliances or upper airway surgery, are more complicated.

A 2014 study led by Schwab compared obese patients with and without sleep apnea, and found that the participants with the condition had significantly larger tongues and a higher percentage of tongue fat when compared to those without sleep apnea. The researchers next step was to determine if reducing tongue fat would improve symptoms and to further examine cause and effect.

The new study included 67 participants with mild to severe obstructive sleep apnea who were obese -- those with a body mass index greater than 30.0. Through diet or weight loss surgery, the patients lost nearly 10 percent of their body weight, on average, over six months. Overall, the participants' sleep apnea scores improved by 31 percent after the weight loss intervention, as measured by a sleep study.

Before and after the weight loss intervention, the study participants underwent MRI scans to both their pharynx as well as their abdomens. Then, using a statistical analysis, the research team quantified changes between overall weight loss and reductions to the volumes of the upper airway structures to determine which structures led to the improvement in sleep apnea. The team found that a reduction in tongue fat volume was the primary link between weight loss and sleep apnea improvement.

The study also found that weight loss resulted in reduced pterygoid (a jaw muscle that controls chewing) and pharyngeal lateral wall (muscles on the sides of the airway) volumes. Both these changes also improved sleep apnea, but not to the same extent as the reduction in tongue fat.

The authors believe that tongue fat is a potential new therapeutic target for improving sleep apnea. They suggest that future studies could be designed to explore whether certain low-fat diets are better than others in reducing tongue fat and whether cold therapies -- like those used to reduce stomach fat -- might be applied to reducing tongue fat. However, Schwab notes, these types of interventions have not yet been tested.

Schwab's team is also examining new interventions and other risk factors for sleep apnea, including whether some patients who are not obese but who have "fatty" tongues could be predisposed to sleep apnea, but are less likely to be diagnosed.

In a recent related study, Schwab found that ethnicity may also play a role in sleep apnea severity. His research team compared the upper airway anatomy of Chinese and Icelandic patients with sleep apnea, and found that, compared to Icelandic patients of similar age, gender, and symptoms, Chinese patients had smaller airways and soft tissues, but bigger soft palate volume with more bone restrictions. This means that Asian patients may generally be more at risk for severe sleep apnea symptoms. The bottom line, according to Schwab, is that all patients who suffer from snoring or sleepiness should be screened for sleep apnea, whether or not they appear to fall into the typical "high-risk" obese categories.

"Primary care doctors, and perhaps even dentists, should be asking about snoring and sleepiness in all patients, even those who have a normal body mass index, as, based on our data, they may also be at risk for sleep apnea," Schwab said.

https://www.sciencedaily.com/releases/2020/01/200110101035.htm