Getting good sleep could add years to your life

Having five low-risk sleep habits may have long-term benefits

February 24, 2023

Science Daily/American College of Cardiology

Getting good sleep can play a role in supporting your heart and overall health -- and maybe even how long you live -- according to new research being presented at the American College of Cardiology's Annual Scientific Session Together With the World Congress of Cardiology. The study found that young people who have more beneficial sleep habits are incrementally less likely to die early. Moreover, the data suggest that about 8% of deaths from any cause could be attributed to poor sleep patterns.

"We saw a clear dose-response relationship, so the more beneficial factors someone has in terms of having higher quality of sleep, they also have a stepwise lowering of all cause and cardiovascular mortality," said Frank Qian, MD, an internal medicine resident physician at Beth Israel Deaconess

Medical Center, clinical fellow in medicine at Harvard Medical School and co-author of the study. "I think these findings emphasize that just getting enough hours of sleep isn't sufficient. You really have to have restful sleep and not have much trouble falling and staying asleep."

For their analysis, Qian and team included data from 172,321 people (average age 50 and 54% women) who participated in the National Health Interview Survey between 2013 and 2018. This survey is fielded each year by the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics to help gauge the health of the U.S. population and includes questions about sleep and sleep habits. Qian said this is the first study to his knowledge to use a nationally representative population to look at how several sleep behaviors, and not just sleep duration, might influence life expectancy.

About two-thirds of study participants self-reported as being White, 14.5% Hispanic, 12.6% Black and 5.5% Asian. Because researchers were able to link participants to the National Death Index records (through December 31, 2019), they could examine the association between individual and combined sleep factors and all-cause and cause-specific mortality. Participants were followed for a median of 4.3 years during which time 8,681 individuals died. Of these deaths, 2,610 deaths (30%) were from cardiovascular disease, 2,052 (24%) were from cancer and 4,019 (46%) were due to other causes.

Researchers assessed ?ve different factors of quality sleep using a low-risk sleep score they created based on answers collected as part of the survey. Factors included: 1) ideal sleep duration of seven to eight hours a night; 2) difficulty falling asleep no more than two times a week; 3) trouble staying asleep no more than two times a week; 4) not using any sleep medication; and 5) feeling well rested after waking up at least five days a week. Each factor was assigned zero or one point for each, for a maximum of five points, which indicated the highest quality sleep.

"If people have all these ideal sleep behaviors, they are more likely to live longer," Qian said. "So, if we can improve sleep overall, and identifying sleep disorders is especially important, we may be able to prevent some of this premature mortality."

For the analysis, researchers controlled for other factors that may have heightened the risk of dying, including lower socioeconomic status, smoking and alcohol consumption and other medical conditions. Compared to individuals who had zero to one favorable sleep factors, those who had all five were 30% less likely to die for any reason, 21% less likely to die from cardiovascular disease, 19% less likely to die from cancer, and 40% less likely to die of causes other than heart disease or cancer. Qian said these other deaths are likely due to accidents, infections or neurodegenerative diseases, such as dementia and Parkinson's disease, but more research is needed.

Among men and women who reported having all five quality sleep measures (a score of five), life expectancy was 4.7 years greater for men and 2.4 years greater for women compared with those who had none or only one of the five favorable elements of low-risk sleep. More research is needed to determine why men with all five low-risk sleep factors had double the increase in life expectancy compared with women who had the same quality sleep.

"Even from a young age, if people can develop these good sleep habits of getting enough sleep, making sure they are sleeping without too many distractions and have good sleep hygiene overall, it can greatly benefit their overall long-term health," Qian said, adding that for the present analysis they estimated gains in life expectancy starting at age 30, but the model can be used to predict gains at older ages too. "It's important for younger people to understand that a lot of health behaviors are cumulative over time. Just like we like to say, 'it's never too late to exercise or stop smoking,' it's also never too early. And we should be talking about and assessing sleep more often."

These sleep habits can be easily asked about during clinical encounters, and the researchers hope patients and clinicians will start talking about sleep as part of their overall health assessment and disease management planning.

One limitation of the study is that sleep habits were self-reported and not objectively measured or verified. In addition, no information was available about the types of sleep aid or medicine used or how often or long participants used them. Future research is needed to understand how these gains in life expectancy might continue as people age, as well as further explore the sex differences that were observed.

Previous studies have shown that getting too little or too much sleep can negatively affect the heart. It's also been widely reported that sleep apnea, a sleep disorder that causes someone to pause or stop breathing while asleep, can lead to a number of heart conditions, including high blood pressure, atrial fibrillation and heart attacks.

https://www.sciencedaily.com/releases/2023/02/230224135111.htm

Exercise more effective than medicines to manage mental health

February 23, 2023

Science Daily/University of South Australia

University of South Australia researchers are calling for exercise to be a mainstay approach for managing depression as a new study shows that physical activity is 1.5 times more effective than counselling or the leading medications.

Published in the British Journal of Sports Medicine, the review is the most comprehensive to date, encompassing 97 reviews, 1039 trials and 128,119 participants. It shows that physical activity is extremely beneficial for improving symptoms of depression, anxiety, and distress.

Specifically, the review showed that exercise interventions that were 12 weeks or shorter were most the effective at reducing mental health symptoms, highlighting the speed at which physical activity can make a change.

The largest benefits were seen among people with depression, pregnant and postpartum women, healthy individuals, and people diagnosed with HIV or kidney disease.

According to the World Health Organization, one in every eight people worldwide (970 million people) live with a mental disorder. Poor mental health costs the world economy approximately $2.5 trillion each year, a cost projected to rise to $6 trillion by 2030. In Australia, an estimated one in five people (aged 16-85) have experienced a mental disorder in the past 12 months.

Lead UniSA researcher, Dr Ben Singh, says physical activity must be prioritised to better manage the growing cases of mental health conditions.

"Physical activity is known to help improve mental health. Yet despite the evidence, it has not been widely adopted as a first-choice treatment," Dr Singh says.

"Our review shows that physical activity interventions can significantly reduce symptoms of depression and anxiety in all clinical populations, with some groups showing even greater signs of improvement.

"Higher intensity exercise had greater improvements for depression and anxiety, while longer durations had smaller effects when compared to short and mid-duration bursts.

"We also found that all types of physical activity and exercise were beneficial, including aerobic exercise such as walking, resistance training, Pilates, and yoga.

"Importantly, the research shows that it doesn't take much for exercise to make a positive change to your mental health."

Senior researcher, UniSA's Prof Carol Maher, says the study is the first to evaluate the effects of all types of physical activity on depression, anxiety, and psychological distress in all adult populations.

"Examining these studies as a whole is an effective way to for clinicians to easily understand the body of evidence that supports physical activity in managing mental health disorders.

"We hope this review will underscore the need for physical activity, including structured exercise interventions, as a mainstay approach for managing depression and anxiety."

https://www.sciencedaily.com/releases/2023/02/230223193417.htm

Air pollution speeds bone loss from osteoporosis

February 21, 2023

Science Daily/Columbia University's Mailman School of Public Health

Elevated levels of air pollutants are associated with bone damage among postmenopausal women, according to new research led by scientists at Columbia University Mailman School of Public Health. The effects were most evident on the lumbar spine, with nitrous oxides twice as damaging to the area than seen with normal aging.

The research findings appear in the peer-reviewed journal eClinicalMedicine, part of The Lancet Discovery Science suite of open-access journals.

Previous studies on individual pollutants have suggested adverse effects on bone mineral density, osteoporosis risk, and fractures in older individuals. The new study is the first to explore the connection between air pollution and bone mineral density specifically in postmenopausal women, and the first to explore the effects of air pollution mixtures on bone outcomes.

The researchers analyzed data collected through the Women's Health Initiative study, an ethnically diverse cohort of 161,808 postmenopausal women. They estimated air pollution (PM10, NO, NO2, and SO2) exposures based on participants' home addresses. They measured bone mineral density (BMD; whole-body, total hip, femoral neck, and lumbar spine) at enrollment at follow-up at year one, year three, and year six using dual-energy X-ray absorptiometry.

The magnitude of the effects of nitrogen oxides on lumbar spine BMD would amount to 1.22 percent annual reductions -- nearly double the annual effects of age on any of the anatomical sites evaluated. These effects are believed to happen through bone cell death by way of oxidative damage and other mechanisms.

"Our findings confirm that poor air quality may be a risk factor for bone loss, independent of socioeconomic or demographic factors. For the first time, we have evidence that nitrogen oxides, in particular, are a major contributor to bone damage and that the lumbar spine is one of the most susceptible sites of this damage," says study first author Diddier Prada, MD, PhD, associate research scientist in the Department of Environmental Health Sciences at Columbia Mailman School of Public Health.

"Improvements in air pollution exposure, particularly nitrogen oxides, will reduce bone damage in postmenopausal women, prevent bone fractures, and reduce the health cost burden associated with osteoporosis among postmenopausal women. Further efforts should focus on detecting those at higher risk of air pollution-related bone damage," says lead author Andrea Baccarelli, MD, PhD, chair of the Department of Environmental Health Sciences at Columbia Mailman School of Public Health.

Car and truck exhaust is a major source of nitrous oxides, as are the emissions from electrical power generation plants.

Approximately 2.1 million osteoporosis-related bone fractures occur annually, resulting in up to $20.3 billion in annual direct health costs. Osteoporosis impacts women more than men, with 80 percent of the estimated 10 million Americans with osteoporosis being women. Postmenopausal women are at higher risk, with one in two women over 50 experiencing a bone fracture because of osteoporosis.

Previously, Columbia researchers showed that long-term air pollution exposure reduces BMD and increases bone fracture risk in later life. Subsequently, these findings have been confirmed in multiple human studies.

https://www.sciencedaily.com/releases/2023/02/230221132129.htm

Working a four-day week boosts employee wellbeing while preserving productivity, major six-month trial finds

February 21, 2023

Science Daily/University of Cambridge

Sixty-one organisations in the UK committed to a 20% reduction in working hours for all staff, with no fall in wages, for a six-month period starting in June 2022. The vast majority of companies also retained full-time productivity targets.

Now, results from the world's largest trial of a four-day working week reveal significantly reduced rates of stress and illness in the workforce -- with 71% of employees self-reporting lower levels of "burnout," and 39% saying they were less stressed, compared to the start of the trial.

There was a 65% reduction in sick days, and a 57% fall in the number of staff leaving participating companies, compared to the same period the previous year. Company revenue barely changed during the trial period -- even increasing marginally by 1.4% on average.

In a report of the findings presented to UK lawmakers, some 92% of companies that took part in the UK pilot programme (56 out of 61) say they intend to continue with the four-day working week, with 18 companies confirming the change as permanent.

Research for the UK trials was conducted by a team of social scientists from the University of Cambridge, working with academics from Boston College in the US and the think tank Autonomy. The trial was organised by 4 Day Week Global in conjunction with the UK's 4 Day Week Campaign.

Companies from across the UK took part, with around 2,900 employees dropping a day of work. Organisations involved in the trial ranged from online retailers and financial service providers to animation studios and a local fish-and-chip shop.

Other industries represented include consultancy, housing, IT, skincare, recruitment, hospitality, marketing, and healthcare.

Researchers surveyed employees throughout the trial to gauge the effects of having an extra day of free time. Self-reported levels of anxiety and fatigue decreased across workforces, while mental and physical health improved.

Many survey respondents said they found it easier to balance work with both family and social commitments: 60% of employees found an increased ability to combine paid work with care responsibilities, and 62% reported it easier to combine work with social life.

"Before the trial, many questioned whether we would see an increase in productivity to offset the reduction in working time -- but this is exactly what we found," said sociologist Prof Brendan Burchell, who led the University of Cambridge side of the research.

"Many employees were very keen to find efficiency gains themselves. Long meetings with too many people were cut short or ditched completely. Workers were much less inclined to kill time, and actively sought out technologies that improved their productivity."

Dr David Frayne, a Research Associate at the University of Cambridge, said: "We feel really encouraged by the results, which showed the many ways companies were turning the four-day week from a dream into realistic policy, with multiple benefits."

Joe Ryle, Director of the 4 Day Week Campaign, calls the results a "major breakthrough moment" for the idea of shorter working weeks. "Across a wide variety of different sectors of the economy, these incredible results show that the four-day week actually works."

In addition to the survey work, designed in collaboration with colleagues including Prof Juliet Schor from Boston College, the Cambridge team conducted a large number of extensive interviews with employees and company CEOs before, during and after the six-month trial.

Other pilots run by 4 Day Week Global in the US and Ireland -- with research conducted by many of the same academics -- have already reported their findings. However, the UK trial is not only the largest to date but also the first to include in-depth interview research.

"The method of this pilot allowed our researchers to go beyond surveys and look in detail at how the companies were making it work on the ground," said Frayne, from Cambridge's Department of Sociology.

In terms of motivations, several senior managers told researchers they saw the four-day week as a rational response to the pandemic -- and believed it would give them an edge when it came to attracting talent in the post-Covid job market.

Some saw it as an appealing alternative to unlimited home working, which they felt risked company culture. Others had seen staff suffer through health problems and bereavement during the pandemic, and felt an increased "moral responsibility" towards employees.

"I hated the pandemic, but it's made us see each other much more in the round, and it's made us all realise the importance of having a healthy head, and that family matters," said the CEO of a non-profit organisation that took part in the trial.

However, many said shorter hours were being discussed long before Covid as a response to demanding or emotionally draining work. The CEO of a video game studio pointed to high-profile examples of "crunch and burnout" in their industry as a reason for involvement in the trial.

Perhaps surprisingly, however, no organisation interviewed was taking part in the trials simply because technology had reduced their need for human labour.

Some companies stopped work completely for a three-day weekend, while others staggered a reduced workforce over a week. One restaurant calculated their 32-hour week over an entire year to have long opening times in the summer, but much shorter in winter.

A few companies in the trial attached strings to the reduced hours, including fewer holiday days, agreement that staff could be called in at short notice, or a "conditional" four-day week: one that only continued while performance targets were met.

Interviews documented how companies reduced working hours without compromising on targets. Common methods included shorter meetings with clearer agendas; introduction of interruption-free 'focus periods'; reforming email etiquette to reduce long chains and inbox churn; new analyses of production processes; end-of-day task lists for effective handovers or next-day head starts.

When employees were asked how they used additional time off, by far the most popular response was "life admin": tasks such as shopping and household chores. Many explained how this allowed them a proper break for leisure activities on Saturday and Sunday.

"It was common for employees to describe a significant reduction in stress," said researcher and Cambridge PhD candidate Niamh Bridson Hubbard. "Many described being able to switch off or breathe more easily at home. One person told us how their 'Sunday dread' had disappeared."

For some parents of young children, a midweek day off meant savings on childcare expenses. For those with older children, it meant some welcome 'me time'. All reported doing more of the activities they already enjoy -- from sport to cooking, music making to volunteering. Some developed new interests, while others used the time to get professional qualifications.

"When you realise that day has allowed you to be relaxed and rested, and ready to absolutely go for it on those other four days, you start to realise that to go back to working on a Friday would feel really wrong -- stupid actually," said the CEO of a consultancy organisation involved in the trial.

When it came to working culture, employees were generally positive, feeling more valued by their employer and describing a shared sense of purpose arising from efforts to make the four-day week a success.

However, several staff at one large company had concerns about intensifying workloads, while some at creative companies expressed disquiet over reduced worktime conviviality due to 'focus time', and argued that unstructured chat often generates new ideas.

By the end of the six-month trial, many of the managers said they could not imagine returning to a five-day week. "Almost everyone we interviewed described being overwhelmed with questions from other organisations in their industry that are interested in following suit," said Burchell.

"When we ask employers, a lot of them are convinced the four-day week is going to happen. It has been uplifting for me personally, just talking to so many upbeat people over the last six months. A four-day week means a better working life and family life for so many people."

https://www.sciencedaily.com/releases/2023/02/230221113132.htm

Psychological stress impedes performance, even for Olympic athletes

February 16, 2023

Science Daily/Association for Psychological Science

The 2020 Tokyo Olympics were unique not just for taking place during the COVID-19 pandemic but for being the first athletic event to measure and broadcast competitors' heart rates as world-class archers took a shot at Olympic gold. Analysis of these biometric data by Yunfeng Lu (Nanjing University) and Songfa Zhong (National University of Singapore, New York University Abu Dhabi) in Psychological Science provides empirical support for something sports fans have long suspected: When athletes feel the pressure, their performance suffers.

"We found that high contactless real-time heart rate is associated with poor performance," said Lu and Zhong in an interview. "This suggests that even the best professional athletes are negatively influenced by psychological stress, even though they are generally well trained to cope with pressure."

Olympic archery includes several types of individual and team-based competitions, but for this study, Lu and Zhong focused on within-gender individual competitions for which heart-rate data were available. During these competitions, the heart rates of 122 male and female archers were broadcast as they took 2,247 shots. The World Archery Federation, in collaboration with Panasonic, measured athletes' heart rates using high-frame-rate cameras that are designed to detect skin reflectance and can determine a person's heart rate 96% as accurately as a pulse oximeter or electrocardiogram.

During each match, individual archers shot a set number of arrows at a target, with a 20-s time limit for each shot. Archers could earn a maximum of 10 points for a perfect bulls-eye shot, with points decreasing the farther an arrow landed from the center of the target.

Lu and Zhong found that athletes whose heart rates were higher before taking a shot consistently scored lower on those shots. While archers' age and gender were not found to significantly influence the relationship between stress and performance, a number of factors related to the nature of the competition did.

Increased heart rate was more likely to reduce the performance of lower-ranking archers and of all archers who shot second in a match or who had a lower score than their opponent at that point in the match. There was also a stronger relationship between stress and performance closer to the end of each match, possibly due to the increase in pressure as athletes progressed in the competition, the authors wrote.

"Elite athletes usually receive training to manage psychological stress, but our results suggest that they continue to be subject to the influence of psychological stress," wrote Lu and Zhong.

In addition to offering evidence for the link between stress and performance in a real-life setting, this research demonstrates that heart rate captured by high-frame-rate cameras can serve as a reliable source of biometric data, according to Lu and Zhong, particularly in situations like the COVID-19 pandemic in which researchers and participants may be unable to meet in person.

"This method could become increasingly important in diverse settings, ranging from sports and business to mental health and medicine," the researchers wrote. "In this regard, our study can be viewed as a proof of concept by showing that contactless real-time heart rates captured psychological stress."

In future work, this technology could be used to observe how psychological stress influences athletic performance across different sports, Lu and Zhong said. The researchers would also like to further investigate how contactless real-time heart rate can be incorporated into behavioral studies in laboratory and field settings.

https://www.sciencedaily.com/releases/2023/02/230216083952.htm

Chronically disrupted sleep may increase the risk for heart disease

February 15, 2023

Science Daily/Vanderbilt University Medical Center

Sleep irregularity — chronically disrupted sleep and highly variable sleep durations night after night — may increase the risk for atherosclerosis, according to a study led by Kelsie Full, PhD, MPH, of Vanderbilt University Medical Center.

The multicenter study, reported Feb. 15 in the Journal of the American Heart Association, followed 2,032 older, racially and ethnically diverse participants from six communities around the United States.

When monitored over a seven-day period, participants with greater irregularity in their sleep duration were more likely to have a higher burden of coronary artery calcium, more plaque in their carotid arteries, and greater systemic atherosclerosis and stiffness in their blood vessels, commonly referred to as “hardening of the arteries.”

“These results suggest that maintaining regular or habitual sleep durations, or sleeping close to the same total amount of time each night, may play an important role in preventing cardiovascular disease,” said Full, a former postdoctoral fellow at the University of Minnesota who joined the Vanderbilt faculty last year as assistant professor of Medicine in the Division of Epidemiology.

The Multi?Ethnic Study of Atherosclerosis (MESA) Sleep Ancillary Study included participants from St. Paul, Minnesota; Baltimore; Chicago; Forsyth County, North Carolina; Los Angeles County, California; and northern Manhattan and the Bronx, New York.

The study excluded shift workers, who are likely to have irregular sleep patterns, and those with existing heart disease and obstructive sleep apnea, a known risk factor for coronary artery disease.

Among the study’s participants, those with more irregular sleep durations were more likely to have atherosclerosis in the coronary arteries and peripheral arteries. These findings suggest that doctors who encourage their patients to maintain regular sleep patterns can help them reduce their risk of cardiovascular disease, Full said.

Full’s coauthors were from Brigham and Women’s Hospital and Harvard Medical School in Boston, the Icahn School of Medicine at Mount Sinai, New York, the University of California, San Diego, and Johns Hopkins School of Medicine in Baltimore.

Disruption of the body’s circadian rhythm may be the link between disrupted sleep and cardiovascular disease. “Almost all major cardiovascular functions, including heart rate, blood pressure, vascular tone, and endothelial functions, are regulated by circadian clock genes,” the researchers reported. 

“Disruption or misalignment of circadian rhythms,” they wrote, “can interrupt these important cardiovascular functions, resulting in the promotion of chronic inflammation, alterations in glucose metabolism, heightened sympathetic nervous system activation, and increases in arterial pressures, all predisposing to the risk of atherosclerosis progression.”

https://www.sciencedaily.com/releases/2023/02/230215100414.htm

Nightly sleep is key to student success

A new study shows the impact of nightly sleep on a student's academic performance

February 13, 2023

Science Daily/Carnegie Mellon University

College is a time of transition for young adults. It may be the first time students have the freedom to determine how to spend their time, but this freedom comes with competing interests from academics, social events and even sleep.

A multi-institutional team of researchers conducted the first study to evaluate how the duration of nightly sleep early in the semester affects first year college students end-of-semester grade point average (GPA). Using Fitbit sleep trackers, they found that students on average sleep 6.5 hours a night, but negative outcomes accumulate when students received less than six hours of sleep a night. The results are available in the Feb. 13 issue of the Proceedings of the National Academy of Sciences.

Previous studies have shown that total sleep is an important predictor for a broad range of health and performance outcomes. Sleep guidelines recommend teenagers get 8 to 10 hours of sleep every night. Many college students experience irregular and insufficient sleep.

David Creswell, the William S. Dietrich II Professor in Psychology and Neuroscience at the Dietrich College of Humanities and Social Sciences, led a team of researchers to evaluate the relationship between sleep and GPA. College students often push themselves to achieve, and GPA is the important marker of academic success.

"Animal studies have shown how critical sleep is for learning and memory," said Creswell. Here we show how this work translates to humans. The less nightly sleep a first year college student gets at the beginning of the school term predicts lower GPA at the end of the term, some five to nine weeks later. Lack of sleep may be hurting students' ability to learn in their college classrooms."

Past work with animals has shown that memories that form during the day are consolidated during sleep. When normal sleep patterns are interrupted, the content learned during the day is lost. Extending this logic to students, the researchers were curious if interrupted or inadequate sleep could impair their academic learning and if this would be apparent by academic achievement.

The study evaluated more than 600 first-year students across five studies at three universities. The students wore wrist Fitbit devices to monitor and record their sleep patterns. The researchers found that students in the study sleep on average 6.5 hours a night.

More surprising, the researchers found that students who receive less than six hours of sleep experienced a pronounced decline in academic performance. In addition, each hour of sleep lost corresponded to a 0.07 decrease in end-of-term GPA.

"Once you start dipping below six hours, you are starting to accumulate massive sleep debt that can impair a student's health and study habits, compromising the whole system," said Creswell. "Most surprising to me was that no matter what we did to make the effect go away, it persisted."

The study controlled for past academic performance, daytime napping, race, gender and first-generation status. Several of the studies also controlled for total academic course load. None of these factors affected the overall impact of nightly sleep on GPA.

"A popular belief among college students is value studying more or partying more over nightly sleep," said Creswell. Our work here suggests that there are potentially real costs to reducing your nightly sleep on your ability to learn and achieve in college. There's real value in budgeting for the importance of nightly sleep."

This works suggests the importance of building structured programs and interventions at institutions of learning that encourage undergraduate students to focus on their sleep.

https://www.sciencedaily.com/releases/2023/02/230213201029.htm

Fructose could drive Alzheimer's disease

An evolutionary foraging instinct that relied on the sugar fructose, may now be fueling the formation of Alzheimer's disease

February 13, 2023

Science Daily/University of Colorado Anschutz Medical Campus

An ancient human foraging instinct, fueled by fructose production in the brain, may hold clues to the development and possible treatment of Alzheimer's disease (AD), according to researchers at the University of Colorado Anschutz Medical Campus.

The study, published recently in The American Journal of Clinical Nutrition, offers a new way of looking at a fatal disease characterized by abnormal accumulations of proteins in the brain that slowly erode memory and cognition.

"We make the case that Alzheimer's disease is driven by diet," said the study's lead author Richard Johnson, MD, professor at the University of Colorado School of Medicine specializing in renal disease and hypertension. The study co-authors include Maria Nagel, MD, research professor of neurology at the CU School of Medicine.

Johnson and his team suggest that AD is a harmful adaptation of an evolutionary survival pathway used in animals and our distant ancestors during times of scarcity.

"A basic tenet of life is to assure enough food, water and oxygen for survival," the study said. "Much attention has focused on the acute survival responses to hypoxia and starvation. However, nature has developed a clever way to protect animals before the crisis actually occurs."

When threatened with the possibility of starvation, early humans developed a survival response which sent them foraging for food. Yet foraging is only effective if metabolism is inhibited in various parts of the brain. Foraging requires focus, rapid assessment, impulsivity, exploratory behavior and risk taking. It is enhanced by blocking whatever gets in the way, like recent memories and attention to time. Fructose, a kind of sugar, helps damp down these centers, allowing more focus on food gathering.

In fact, the researchers found the entire foraging response was set in motion by the metabolism of fructose whether it was eaten or produced in the body. Metabolizing fructose and its byproduct, intracellular uric acid, was critical to the survival of both humans and animals.

The researchers noted that fructose reduces blood flow to the brain's cerebral cortex involved in self-control, as well as the hippocampus and thalamus. Meanwhile, blood flow increased around the visual cortex associated with food reward. All of this stimulated the foraging response.

"We believe that initially the fructose-dependent reduction in cerebral metabolism in these regions was reversible and meant to be beneficial," Johnson said. "But chronic and persistent reduction in cerebral metabolism driven by recurrent fructose metabolism leads to progressive brain atrophy and neuron loss with all of the features of AD."

Johnson suspects the survival response, what he calls the `survival switch,' that helped ancient humans get through periods of scarcity, is now stuck in the `on' position in a time of relative abundance. This leads to the overeating of high fat, sugary and salty food prompting excess fructose production.

Fructose produced in the brain can lead to inflammation and ultimately Alzheimer's disease, the study said. Animals given fructose show memory lapses, a loss in the ability to navigate a maze and inflammation of the neurons.

"A study found that if you keep laboratory rats on fructose long enough they get tau and amyloid beta proteins in the brain, the same proteins seen in Alzheimer's disease," Johnson said. "You can find high fructose levels in the brains of people with Alzheimer's as well."

Johnson suspects that the tendency of some AD patients to wander off might be a vestige of the ancient foraging response.

The study said more research is needed on the role of fructose and uric acid metabolism in AD.

"We suggest that both dietary and pharmacologic trials to reduce fructose exposure or block fructose metabolism should be performed to determine if there is potential benefit in the prevention, management or treatment of this disease," Johnson said.

https://www.sciencedaily.com/releases/2023/02/230213113345.htm

Mushrooms magnify memory by boosting nerve growth

February 10, 2023

Science Daily/University of Queensland

Researchers from The University of Queensland have discovered the active compound from an edible mushroom that boosts nerve growth and enhances memory.

Professor Frederic Meunier from the Queensland Brain Institute said the team had identified new active compounds from the mushroom, Hericium erinaceus.

Researchers have discovered lion's mane mushrooms improve brain cell growth and memory in pre-clinical trials. 

"Extracts from these so-called 'lion's mane' mushrooms have been used in traditional medicine in Asian countries for centuries, but we wanted to scientifically determine their potential effect on brain cells," Professor Meunier said.

"Pre-clinical testing found the lion's mane mushroom had a significant impact on the growth of brain cells and improving memory.

"Laboratory tests measured the neurotrophic effects of compounds isolated from Hericium erinaceus on cultured brain cells, and surprisingly we found that the active compounds promote neuron projections, extending and connecting to other neurons.

"Using super-resolution microscopy, we found the mushroom extract and its active components largely increase the size of growth cones, which are particularly important for brain cells to sense their environment and establish new connections with other neurons in the brain."

Co-author, UQ's Dr Ramon Martinez-Marmol said the discovery had applications that could treat and protect against neurodegenerative cognitive disorders such as Alzheimer's disease.

"Our idea was to identify bioactive compounds from natural sources that could reach the brain and regulate the growth of neurons, resulting in improved memory formation," Dr Martinez-Marmol said.

Dr Dae Hee Lee from CNGBio Co, which has supported and collaborated on the research project, said the properties of lion's mane mushrooms had been used to treat ailments and maintain health in traditional Chinese medicine since antiquity.

"This important research is unravelling the molecular mechanism of lion's mane mushroom compounds and their effects on brain function, particularly memory," Dr Lee said.

https://www.sciencedaily.com/releases/2023/02/230210115544.htm

How age and sex influence our body clocks

February 7, 2023

Science Daily/Ecole Polytechnique Fédérale de Lausanne

The human body runs on a finely tuned clock synchronized to the 24-hour cycle of Earth's rotation, known as the circadian clock, which controls various physiological processes such as the sleep-wake cycle, hormone production, and metabolism.

In a new study, researchers led by Felix Naef at EPFL were able to uncover the organization of tissue-specific gene expression rhythms in humans, and shed light on how our body clocks depend on sex and age.

In model organisms, analyzing molecular rhythms is usually done using time-stamped measurements -- but such data are not readily available in humans. To work around this, the researchers used existing measurements from a large cohort of post-mortem donors, combined with a novel computer algorithm that was designed to assign internal clock times to nearly one thousand donors.

"Interestingly, the data-science algorithm we developed turned out to resemble models from magnetic systems, which are well studied in statistical physics," says Felix Naef. Using this innovative approach, the researchers obtained the first comprehensive and accurate whole-organism view of 24-hour gene expression rhythms in 46 human tissues.

The study found that the core clock machinery properties are conserved across the body and do not change significantly with sex and age. On the other hand, the analysis revealed extensive programs of gene expression rhythms across major compartments of metabolism, stress response pathways and immune function, and these programs peaked twice a day.

In fact, the emerging whole-body organization of circadian timing shows that rhythmic gene expression occurs as morning and evening waves, with the timing in the adrenal gland peaking first, while brain regions displayed much lower rhythmicity compared to metabolic tissues.

Dividing the donors by sex and age revealed a previously unknown richness of sex- and age- specific gene expression rhythms spread across biological functions. Strikingly, gene expression rhythms were sex-dimorphic (different in males and females) and more sustained in females, while rhythmic programs were generally reduced with age across the body.

Sex-dimorphic rhythms -- referring to the differences between males and females -- were particularly noticeable in the liver's "xenobiotic detoxification," the process by which liver breaks down harmful substances. Additionally, the study found that as people grow older, the rhythm of gene expression decreases in the heart's arteries, which may explain why older people are more susceptible to heart disease. This information could be useful in the field of "chronopharmacology," which is the study of how a person's internal clock affects the effectiveness and side effects of medication.

This study provides new insights into the complex interplay between our body clock, sex, and age. By understanding these rhythms, we might find new ways of diagnosing and treating pathologies such as sleep disorders and metabolic diseases.

https://www.sciencedaily.com/releases/2023/02/230203105329.htm

Learning with all your senses: Multimodal enrichment as the optimal learning strategy of the future

February 1, 2023

Science Daily/Technische Universität Dresden

Many educational approaches assume that integrating complementary sensory and motor information into the learning experience can enhance learning, for example gestures help in learning new vocabulary in foreign language classes. In her recent publication, neuroscientist Katharina von Kriegstein from Technische Universität Dresden and Brian Mathias of the University of Aberdeen summarize these methods under the term "multimodal enrichment." This means enrichment with multiple senses and movement. Numerous current scientific studies prove that multimodal enrichment can enhance learning outcomes. Experiments in classrooms show similar results.

In the review article, the two researchers compare these findings with cognitive, neuroscience, and computational theories of multimodal enrichment. Recent neuroscience research has found that the positive effects of enriched learning are associated with response in brain regions that serve perception and motor function. For example, hearing a recently learned foreign language word, may elicit activity in motor brain regions if the word was associated with the performance of a congruent gesture during learning. These brain responses are causal to the benefits of multimodal enrichment for learning outcome. Computer algorithms confirm this hypothesis.

"The brain is optimized for learning with all the senses and with movement. Brain structures for perception and motor skills work together to promote this type of learning. We hope that our deeper understanding of the brain's learning mechanisms, will facilitate the development of optimal learning strategies in the future," explains Brian Mathias.

Katharina von Kriegstein adds, "The results of the literature we reviewed contribute to our understanding of why several long-used learning strategies, such as parts of the Montessori method, are effective. They also provide clear clues as to why some approaches are not as effective. Recently uncovered neuroscientific mechanisms may inspire the updating of cognitive and computational theories of learning, providing new hypotheses about learning. We anticipate that such an interdisciplinary and evidence-based approach will lead to the optimization of learning and teaching strategies in the future, for both humans and artificial systems."

https://www.sciencedaily.com/releases/2023/02/230201134225.htm

Tuning into brainwave rhythms speeds up learning in adults

January 31, 2023

Science Daily/University of Cambridge

Scientists have shown for the first time that briefly tuning into a person's individual brainwave cycle before they perform a learning task dramatically boosts the speed at which cognitive skills improve.

Calibrating rates of information delivery to match the natural tempo of our brains increases our capacity to absorb and adapt to new information, according to the team behind the study.

University of Cambridge researchers say that these techniques could help us retain "neuroplasticity" much later in life and advance lifelong learning.

"Each brain has its own natural rhythm, generated by the oscillation of neurons working together," said Prof Zoe Kourtzi, senior author of the study from Cambridge's Department of Psychology. "We simulated these fluctuations so the brain is in tune with itself -- and in the best state to flourish."

"Our brain's plasticity is the ability to restructure and learn new things, continually building on previous patterns of neuronal interactions. By harnessing brainwave rhythms, it may be possible to enhance flexible learning across the lifespan, from infancy to older adulthood," Kourtzi said.

The findings, published in the journal Cerebral Cortex, will be explored as part of the Centre for Lifelong Learning and Individualised Cognition: a research collaboration between Cambridge and Nanyang Technological University (NTU), Singapore.

The neuroscientists used electroencephalography -- or EEG -- sensors attached to the head to measure electrical activity in the brain of 80 study participants, and sample brainwave rhythms.

The team took alpha waves readings. The mid-range of the brainwave spectrum, this wave frequency tends to dominate when we are awake and relaxed.

Alpha waves oscillate between eight to twelve hertz: a full cycle every 85-125 milliseconds. However, every person has their own peak alpha frequency within that range.

Scientists used these readings to create an optical "pulse": a white square flickering on a dark background at the same tempo as each person's individual alpha wave.

Participants got a 1.5-second dose of personalised pulse to set their brain working at its natural rhythm -- a technique called "entrainment" -- before being presented with a tricky quick-fire cognitive task: trying to identify specific shapes within a barrage of visual clutter.

A brainwave cycle consists of a peak and trough. Some participants received pulses matching the peak of their waves, some the trough, while some got rhythms that were either random or at the wrong rate (a little faster or slower). Each participant repeated over 800 variations of the cognitive task, and the neuroscientists measured how quickly people improved.

The learning rate for those locked into the right rhythm was at least three times faster than for all the other groups. When participants returned the next day to complete another round of tasks, those who learned much faster under entrainment had maintained their higher performance level.

"It was exciting to uncover the specific conditions you need to get this impressive boost in learning," said first author Dr Elizabeth Michael, now at Cambridge's Cognition and Brain Sciences Unit.

"The intervention itself is very simple, just a brief flicker on a screen, but when we hit the right frequency plus the right phase alignment, it seems to have a strong and lasting effect."

Importantly, entrainment pulses need to chime with the trough of a brainwave. Scientists believe this is the point in a cycle when neurons are in a state of "high receptivity."

"We feel as if we constantly attend to the world, but in fact our brains take rapid snapshots and then our neurons communicate with each other to string the information together," said co-author Prof Victoria Leong, from NTU and Cambridge's Department of Paediatrics.

"Our hypothesis is that by matching information delivery to the optimal phase of a brainwave, we maximise information capture because this is when our neurons are at the height of excitability."

Previous work from Leong's Baby-LINC lab shows that brainwaves of mothers and babies will synchronise when they communicate. Leong believes the mechanism in this latest study is so effective because it mirrors the way we learn as infants.

"We are tapping into a mechanism that allows our brain to align to temporal stimuli in our environment, especially communicative cues like speech, gaze and gesture that are naturally exchanged during interactions between parents and babies," said Leong.

"When adults speak to young children they adopt child-directed speech -- a slow and exaggerated form of speaking. This study suggests that child-directed speech may be a spontaneous way of rate-matching and entraining the slower brainwaves of children to support learning."

The researchers say that, while the new study tested visual perception, these mechanisms are likely to be "domain general": applying to a wide range of tasks and situations, including auditory learning.

They argue that potential applications for brainwave entrainment may sound like the stuff of science fiction, but are increasingly achievable. "While our study used complex EEG machines, there are now simple headband systems that allow you to gauge brain frequencies quite easily," said Kourtzi.

"Children now do so much of their learning in front of screens. One can imagine using brainwave rhythms to enhance aspects of learning for children who struggle in regular classrooms, perhaps due to attentional deficits."

Other early applications of brainwave entrainment to boost learning could involve training in professions where fast learning and quick decision-making is vital, such as pilots or surgeons. "Virtual reality simulations are now an effective part of training in many professions," said Kourtzi.

"Implementing pulses that sync with brainwaves in these virtual environments could give new learners an edge, or help those retraining later in life."

https://www.sciencedaily.com/releases/2023/01/230131101912.htm

Do sleep medications increase your chances of dementia?

January 31, 2023

Science Daily/University of California - San Francisco

A new study shows that sleep medications increase the risk of dementia in whites. But the type and quantity of the medication may be factors in explaining the higher risk.

It follows previous work that shows Blacks have a higher likelihood than whites of developing Alzheimer's, the most common type of dementia, and that they have different risk factors and disease manifestation.

The final corrected draft of the study publishes in the Journal of Alzheimer's Disease on Jan. 31, 2023.

In the study, approximately 3,000 older adults without dementia, who lived outside of nursing homes, were enrolled in the Health, Aging and Body Composition study and followed over an average duration of nine years. Their average age was 74; 42% were Black and 58% were white.

During the study, 20% developed dementia. White participants who "often" or "almost always" took sleep medications had a 79% higher chance of developing dementia compared to those who "never" or "rarely" used them. Among Black participants -- whose consumption of sleep aids was markedly lower -- frequent users had a similar likelihood of developing dementia than those who abstained or rarely used the medications.

Higher-Income Blacks May Be Less Likely to Get Dementia

"Differences may be attributed to socio-economic status" said first author Yue Leng, PhD, of the UCSF Department of Psychiatry and Behavioral Sciences and Weill Institute for Neurosciences. "Black participants who have access to sleep medications might be a select group with high socio-economic status and, thus, greater cognitive reserve, making them less susceptible to dementia.

"It's also possible that some sleep medications were associated with a higher risk of dementia than others."

The researchers found that whites, at 7.7%, were three times as likely as Blacks, at 2.7%, to take sleep medications often, five to 15 times a month, or almost always, 16 times a month to daily. Whites were almost twice as likely to use benzodiazepines, like Halcion, Dalmane and Restoril, prescribed for chronic insomnia.

Whites were also 10 times as likely to take trazodone, an antidepressant known by the trade names of Desyrel and Oleptro, that may also be prescribed as a sleep aid. And they were more than seven times as likely to take "Z-drugs," such as Ambien, a so-called sedative-hypnotic.

While future study may offer clarity on the cognitive risks or rewards of sleep medications and the role that race may play, patients with poor sleep should hesitate before considering medications, according to Leng.

"The first step is to determine what kind of sleep issues patients are dealing with. A sleep test may be required if sleep apnea is a possibility," she said. "If insomnia is diagnosed, cognitive behavioral therapy for insomnia (CBT-i) is the first-line treatment. If medication is to be used, melatonin might be a safer option, but we need more evidence to understand its long-term impact on health."

https://www.sciencedaily.com/releases/2023/01/230131101833.htm

Three or more concussions linked with worse brain function in later life

Experiencing three or more concussions is linked with worsened brain function in later life, according to major new research

January 30, 2023

Science Daily/University of Exeter

Experiencing three or more concussions is linked with worsened brain function in later life, according to major new research.

The study -- the largest of its kind -- also found having just one moderate-to-severe concussion, or traumatic brain injury (TBI), can have a long-term impact on brain function, including memory.

Led by teams at the University of Oxford and the University of Exeter, the research included data from more than 15,000 participants of the online PROTECT study, who were aged between 50 and 90 and based in the UK. They reported the severity and frequency of concussions they had experienced throughout their lives, and completed annual, computerised tests for brain function.

Published in the Journal of Neurotrauma, the paper found that people who reported three or more concussions had significantly worse cognitive function, which got successively worse with each subsequent concussion after that. Attention and completion of complex tasks were particularly affected.

Researchers say people who have had concussions should be warned of the dangers of continuing high-risk sport or work.

Lead investigator Dr Vanessa Raymont, from the University of Oxford, said: "We know that head injuries are a major risk factor for dementia, and this large-scale study gives the greatest detail to date on a stark finding -- the more times you injure your brain in life, the worse your brain function could be as you age.

"Our research indicates that people who have experienced three or more even mild episodes of concussion should be counselled on whether to continue high-risk activities. We should also encourage organisations operating in areas where head impact is more likely to consider how they can protect their athletes or employees."

The team found that participants who reported three episodes of even mild concussion throughout their lives had significantly worse attention and ability to complete complex tasks. Those who had four or more mild concussion episodes also showed worsened processing speed and working memory. Each additional reported concussion was linked to progressively worse cognitive function.

Furthermore, the researchers found that reporting even one moderate-to-severe concussion was associated with worsened attention, completion of complex tasks and processing speed capacity.

In the online PROTECT study, participants share detailed lifestyle information, and complete a suite of cognitive tests every year, for up to 25 years. This rich mine of data helps researchers understand how the brain ages, and the factors involved in maintaining a healthier brain in later life.

Dr Helen Brooker, a study co-author from the University of Exeter, said: "As our population ages, we urgently need new ways to empower people to live healthier lives in later life. This paper highlights the importance of detailed long-term studies like PROTECT in better understating head injuries and the impact to long term cognitive function, particularly as concussion has also been linked to dementia. We're learning that life events that might seem insignificant, life experiencing a mild concussion, can have an impact on the brain. Our findings indicate that cognitive rehabilitation should focus on key functions such as attention and completion of complex tasks, which we found to be susceptible to long-term damage."

Dr Susan Kohlhaas, Director of Research at Alzheimer's Research UK, said: "Studies like this are so important in unravelling the long-term risks of traumatic brain injury, including their effect on dementia risk. These findings should send a clear message to policy makers and sporting bodies, who need to put robust guidelines in place that reduce risk of head injury as much as possible."

https://www.sciencedaily.com/releases/2023/01/230130213948.htm

Why a high fat diet could reduce the brain's ability to regulate food intake

January 26, 2023

Science Daily/The Physiological Society

Regularly eating a high fat/calorie diet could reduce the brain’s ability to regulate calorie intake. New research in rats published in The Journal of Physiologyfound that after short periods of being fed a high fat/high calorie diet, the brain adapts to react to what is being ingested and reduces the amount of food eaten to balance calorie intake. The researchers from Penn State College of Medicine, US, suggest that calorie intake is regulated in the short-term by cells called astrocytes (large star-shaped cells in the brain that regulate many different functions of neurons in the brain) that control the signalling pathway between the brain and the gut. Continuously eating a high fat/calorie diet seems to disrupt this signalling pathway.

Understanding the brain’s role and the complex mechanisms that lead to overeating, a behaviour that can lead to weight gain and obesity, could help develop therapies to treat it. Obesity is a global public-health concern because it is associated with increased risk of cardiovascular diseases and type 2 diabetes. In England, 63% of adults are considered above a healthy weight and around half of these are living with obesity. One in three children leaving primary school are overweight or obese1.

Dr Kirsteen Browning, Penn State College of Medicine, US, said,

“Calorie intake seems to be regulated in the short-term by astrocytes. We found that a brief exposure (three to five days) of high fat/calorie diet has the greatest effect on astrocytes, triggering the normal signalling pathway to control the stomach. Over time, astrocytes seem to desensitise to the high fat food. Around 10-14 days of eating high fat/calorie diet, astrocytes seem to fail to react and the brain’s ability to regulate calorie intake seems to be lost. This disrupts the signalling to the stomach and delays how it empties.”

Astrocytes initially react when high fat/calorie food is ingested. Their activation triggers the release of gliotransmitters, chemicals (including glutamate and ATP) that excite nerve cells and enable normal signalling pathways to stimulate neurons that control how the stomach works. This ensures the stomach contracts correctly to fill and empty in response to food passing through the digestive system. When astrocytes are inhibited, the cascade is disrupted. The decrease in signalling chemicals leads to a delay in digestion because the stomach doesn’t fill and empty appropriately.

The vigorous investigation used behavioural observation to monitor food intake in rats (N=205, 133 males, 72 females) which were fed a control or high fat/calorie diet for one, three, five or 14 days. This was combined with pharmacological and specialist genetic approaches (both in vivo and in vitro) to target distinct neural circuits. Enabling the researchers to specifically inhibit astrocytes in a particular region of the brainstem (the posterior part of the brain that connects the brain to the spinal cord), so they could assess how individual neurons behaved to studying rats' behaviour when awake.

Human studies will need to be carried out to confirm if the same mechanism occurs in humans. If this is the case, further testing will be required to assess if the mechanism could be safely targeted without disrupting other neural pathways.

The researchers have plans to further explore the mechanism. Dr Kirsteen Browning said,

“We have yet to find out whether the loss of astrocyte activity and the signalling mechanism is the cause of overeating or that it occurs in response to the overeating. We are eager to find out whether it is possible to reactivate the brain’s apparent lost ability to regulate calorie intake. If this is the case, it could lead to interventions to help restore calorie regulation in humans.”

https://www.sciencedaily.com/releases/2023/01/230126100217.htm

More steps, moderate physical activity cuts dementia, cognitive impairment risk

January 25, 2023

Science Daily/University of California - San Diego

Senior women were less likely to develop mild cognitive impairment or dementia if they did more daily walking and moderate-to-vigorous physical activity, according to a new study led by the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego.

In the Jan. 25, 2023 online edition of Alzheimer's & Dementia: The Journal of the Alzheimer's Association, the team reported that, among women aged 65 or older, each additional 31 minutes per day of moderate-to-vigorous physical activity was associated with a 21 percent lower risk of developing mild cognitive impairment or dementia. Risk was also 33 percent lower with each additional 1,865 daily steps.

"Given that the onset of dementia begins 20 years or more before symptoms show, the early intervention for delaying or preventing cognitive decline and dementia among older adults is essential," said senior author Andrea LaCroix, Ph.D., M.P.H., Distinguished Professor at the Herbert Wertheim School of Public Health and Human Longevity Science at UC San Diego.

While there are several types, dementias are a debilitating neurological condition that can cause loss of memory, the ability to think, problem solve or reason. Mild cognitive impairment is an early stage of memory loss or thinking problems that is not as severe as dementias.

According to the United States Department of Health and Human Services, dementia affects more than 5 million people in this country. That number is expected to double by 2050.

More women live with and are at higher risk of developing dementia than men.

"Physical activity has been identified as one of the three most promising ways to reduce risk of dementia and Alzheimer's disease. Prevention is important because once dementia is diagnosed, it is very difficult to slow or reverse. There is no cure," said LaCroix.

However, because few large studies have examined device measures of movement and sitting in relation to mild cognitive impairment and dementia, much of the published research on the associations of physical activity and sedentary behavior with cognitive decline and dementia is based on self-reported measures, said first author, Steven Nguyen, Ph.D., M.P.H., postdoctoral scholar at the Herbert Wertheim School of Public Health.

For this study, the researchers sampled data from 1,277 women as part of two Women's Health Initiative (WHI) ancillary studies -- the WHI Memory Study (WHIMS) and the Objective Physical Activity and Cardiovascular Health (OPACH) study. The women wore research-grade accelerometers and went about their daily activities for up to seven days to obtain accurate measures of physical activity and sitting.

The activity trackers showed the women averaged 3,216 steps, 276 minutes in light physical activities, 45.5 minutes of moderate-to-vigorous physical activity and 10.5 hours of sitting per day. Examples of light physical activity could include housework, gardening or walking. Moderate-to-vigorous physical activity could include brisk walking.

The study findings also showed that higher amounts of sitting and prolonged sitting were not associated with higher risk of mild cognitive impairment or dementia.

Together, this information has clinical and public health importance as there is little published information on the amount and intensity of physical activity needed for a lower dementia risk, said Nguyen.

"Older adults can be encouraged to increase movement of at least moderate intensity and take more steps each day for a lower risk of mild cognitive impairment and dementia," said Nguyen.

"The findings for steps per day are particularly noteworthy because steps are recorded by a variety of wearable devices increasingly worn by individuals and could be readily adopted."

The authors said further research is needed among large diverse populations that include men.

https://www.sciencedaily.com/releases/2023/01/230125085831.htm

Traffic pollution impairs brain function

First-in-the-world study suggests that even brief exposure to air pollution has rapid impacts on the brain

January 24, 2023

Science Daily/University of British Columbia

A new study by researchers at the University of British Columbia and the University of Victoria has shown that common levels of traffic pollution can impair human brain function in only a matter of hours.

The peer-reviewed findings, published in the journal Environmental Health, show that just two hours of exposure to diesel exhaust causes a decrease in the brain's functional connectivity -- a measure of how The study provides the first evidence in humans, from a controlled experiment, of altered brain network connectivity induced by air pollution.

"For many decades, scientists thought the brain may be protected from the harmful effects of air pollution," said senior study author Dr. Chris Carlsten, professor and head of respiratory medicine and the Canada Research Chair in occupational and environmental lung disease at UBC. "This study, which is the first of its kind in the world, provides fresh evidence supporting a connection between air pollution and cognition."

For the study, the researchers briefly exposed 25 healthy adults to diesel exhaust and filtered air at different times in a laboratory setting. Brain activity was measured before and after each exposure using functional magnetic resonance imaging (fMRI).

The researchers analyzed changes in the brain's default mode network (DMN), a set of inter-connected brain regions that play an important role in memory and internal thought. The fMRI revealed that participants had decreased functional connectivity in widespread regions of the DMN after exposure to diesel exhaust, compared to filtered air.

"We know that altered functional connectivity in the DMN has been associated with reduced cognitive performance and symptoms of depression, so it's concerning to see traffic pollution interrupting these same networks," said Dr. Jodie Gawryluk, a psychology professor at the University of Victoria and the study's first author. "While more research is needed to fully understand the functional impacts of these changes, it's possible that they may impair people's thinking or ability to work."

Taking steps to protect yourself

Notably, the changes in the brain were temporary and participants' connectivity returned to normal after the exposure. Dr. Carlsten speculated that the effects could be long lasting where exposure is continuous. He said that people should be mindful of the air they're breathing and take appropriate steps to minimize their exposure to potentially harmful air pollutants like car exhaust.

"People may want to think twice the next time they're stuck in traffic with the windows rolled down," said Dr. Carlsten. "It's important to ensure that your car's air filter is in good working order, and if you're walking or biking down a busy street, consider diverting to a less busy route."

While the current study only looked at the cognitive impacts of traffic-derived pollution, Dr. Carlsten said that other products of combustion are likely a concern.

"Air pollution is now recognized as the largest environmental threat to human health and we are increasingly seeing the impacts across all major organ systems," says Dr. Carlsten. "I expect we would see similar impacts on the brain from exposure to other air pollutants, like forest fire smoke. With the increasing incidence of neurocognitive disorders, it's an important consideration for public health officials and policymakers."

The study was conducted at UBC's Air Pollution Exposure Laboratory, located at Vancouver General Hospital, which is equipped with a state-of-the-art exposure booth that can mimic what it is like to breathe a variety of air pollutants. In this study, which was carefully designed and approved for safety, the researchers used freshly-generated exhaust that was diluted and aged to reflect real-world conditions.

https://www.sciencedaily.com/releases/2023/01/230124112731.htm

Head injury is associated with doubled mortality rate long-term

More severe head injuries increased mortality rates in the 30-year study period

January 24, 2023

Science Daily/University of Pennsylvania School of Medicine

Adults who suffered any head injury during a 30-year study period had two times the rate of mortality than those who did not have any head injury, and mortality rates among those with moderate or severe head injuries were nearly three times higher, according to new research from the Perelman School of Medicine at the University of Pennsylvania, published today in JAMA Neurology.

In the United States, over 23 million adults age 40 or older report a history of head injury with loss of consciousness. Head injury can be attributed to a number of causes, from motor vehicle crashes, unintentional falls, or sports injuries. What's more, head injury has been linked with a number of long-term health conditions, including disability, late-onset epilepsy, dementia, and stroke.

Studies have previously shown increased short-term mortality associated with head injuries primarily among hospitalized patients. This longitudinal study evaluated 30 years of data from over 13,000 community-dwelling participants (those not hospitalized or living in nursing home facilities) to determine if head injury has an impact on mortality rates in adults over the long term. Investigators found that 18.4 percent of the participants reported one or more head injuries during the study period, and of those who suffered a head injury, 12.4 percent were recorded as moderate or severe. The median period of time between a head injury and death was 4.7 years.

Death from all causes was recorded in 64.6 percent of those individuals who suffered a head injury, and in 54.6 percent of those without any head injury. Accounting for participant characteristics, investigators found that the mortality rate from all-causes among participants with a head injury was 2.21 times the mortality rate among those with no head injury. Further, the mortality rate among those with more severe head injuries was 2.87 times the mortality rate among those with no head injury.

"Our data reveals that head injury is associated with increased mortality rates even long-term. This is particularly the case for individuals with multiple or severe head injuries," explained the study's lead author, Holly Elser, MD, PhD, MPH a Neurology resident at Penn. "This highlights the importance of safety measures, like wearing helmets and seatbelts, to prevent head injuries."

Investigators also evaluated the data for specific causes of death among all participants. Overall, the most common causes of death were cancers, cardiovascular disease, and neurologic disorders (which include dementia, epilepsy, and stroke). Among individuals with head injuries, deaths caused by neurologic disorders and unintentional injury or trauma (like falls) occurred more frequently.

When investigators evaluated specific neurologic causes of death among participants with head injury, they found that nearly two-thirds of neurologic causes of death were attributed to neurodegenerative diseases, like Alzheimer's and Parkinson's disease. These diseases composed a greater proportion of overall deaths among individuals with head injury (14.2 percent) versus those without (6.6 percent).

"Study data doesn't explain why the cause of death in individuals with head injuries is more likely to be from neurodegenerative diseases, which underscores the need for further research into the relationship between these disorders, head injury, and death," said Andrea L.C. Schneider, MD, PhD, an assistant professor of Neurology at Penn.

https://www.sciencedaily.com/releases/2023/01/230124192620.htm

Childhood trauma linked to civic environmental engagement, green behavior

January 23, 2023

Science Daily/University of Colorado at Boulder

Experiencing childhood trauma may lead an individual to volunteer, donate money or contact their elected officials about environmental issues later in life, according to recent research published in Scientific Reports.

The CU Boulder and Loyola University study is one of the first in the U.S. to associate childhood trauma and public, civic environmental engagement in adulthood. It also found that, in addition to people who experienced childhood trauma, those who traveled and had experiences in nature as children were also more likely to report engaging in private "green behavior" as adults, such as recycling, driving or flying less, and taking shorter showers.

"We set out to explore reasons or motivations why someone would get environmentally engaged versus not and experiencing childhood trauma emerged as a really powerful motivator," said lead author Urooj Raja, who earned her doctorate in environmental studies at CU Boulder in 2021.

As part of Raja's doctoral work, the researchers conducted a survey in 2020 using a nationally representative sample of about 450 U.S. adults to examine two types of environmental engagement. Public, civic engagement was measured in hours per month devoted to an environmental protection cause, such as writing letters to elected officials or donating time and resources to an organization. Private, green behavior was defined as self-reported actions adopted by individuals or households to reduce their environmental impact.

Previous research has shown that people who experience natural disasters as children are more likely to get involved in environmental causes, but these new findings show that childhood trauma of any kind is associated with increased interest in both private and public environment engagement as an adult. This indicates there may be something about a formative, negative experience that drives individuals to engage on a public or policy level with environmental issues, instead of only practicing green behavior.

"It suggests that there could be another way of looking at trauma," said Raja, now an assistant professor in the School of Communication at Loyola University Chicago.

While the researchers can't say exactly why experiencing traumatic events earlier in life boosts the likelihood of getting publicly involved in environmental issues, they note that previous research has associated trauma with a strong sense of empathy, and empathy with green behavior.

It could also partly be a coping mechanism, to attempt to keep bad things from happening to other people or living things, said Raja.

Drivers of environmental engagement 

Research in this area has often examined disengagement -- the reasons why people don't act on pressing environmental issues. Raja's team wanted to know: What drives those who do engage?

First, Raja interviewed 33 people who are highly engaged in environmental issues. She discovered that many had experienced some kind of childhood trauma.

"It emerged as a very powerful piece of why people wanted to and became engaged with environmental work," said Raja.

Second, they gathered survey data from about 450 U.S. adults who self-reported that they spent five hours or more in the past month working on environmental issues. They answered a series of questions about themselves, including their current civic engagement and green behavior, formative childhood experiences (gardening, swimming in a lake or going on a hike in the woods for the first time), and traumatic experiences in childhood (living in poverty or experiencing hunger, not having a safe home environment, losing a parent or sibling, dealing with health issues, or enduring sexual harassment, assault or bullying).

The data revealed that childhood experiences in nature, travel and trauma were all predictors of private, green behavior later in life. However, only childhood trauma was also significantly associated with public, civic engagement. Trauma also had the largest impact on predicting green behavior, compared to other formative life experiences.

Studies in decades past -- including work by Louise Chawla, professor emerita in the Program in Environmental Design -- have found a strong link between childhood travel and experiences in nature and pro-environmental attitudes and behaviors later in life. The new survey confirms that these types of childhood experiences still predict green behavior for adults today.

"This is another data point that supports the value of creating opportunities for people to connect with nature, and the importance of those experiences for cultivating a society that protects the natural resources that we all depend on," said Amanda Carrico, co-author of the new study and associate professor in the Department of Environmental Studies at CU Boulder.

A need for more resources and support 

Carrico, who is trained as an environmental psychologist and teaches courses on climate change, has noticed that many students and professionals in the field struggle not only with the weight of their work, but also with the experiences that may have led them to it.

"It's emotionally intense and exhausting," said Carrico, noting that those who work on mitigating climate change are also often part of communities directly affected by its growing impacts. "You're talking about a community of people that seem to be carrying other kinds of emotionally complex burdens."

The authors say that the findings only further emphasize the need for people engaged in public-facing or civic environmental work to have access to resources and support.

"People, in their own words, have said that we need better resources," said Raja. "Making the link between adverse childhood experiences and the need for more resources for people that do this type of work is an important first step to making that happen."

https://www.sciencedaily.com/releases/2023/01/230123083446.htm

Loneliness associated with unhealthful diets and physical inactivity among US college students

January 20, 2023

Science Daily/George Mason University

Transitioning to a new environment, as many college freshman do, can increase feelings of loneliness, and feelings of loneliness in college students have dramatically increased in the last decade, according to the National College Health Assessment. Additionally, a 2021 survey reported that 44% of U.S. college students described their weight as more than normal, i.e. either in the overweight or obese category. Though loneliness has been linked to unhealthy weight and physical inactivity, there is a lack of research on dietary behaviors in college students and the role it can play in obesity in college students.

With data from the Mason: Health Starts Here cohort study, Master of Nutrition alum Li Jiang found that loneliness was related to altered diet quality and physical inactivity. The research was done as part of Jiang's master's thesis, and Mason Nutrition and Food Studies Department Chair Lawrence J. Cheskin, Associate Professor Lilian de Jonge, former faculty member Cara Frankenfeld, and former postdoctoral fellow Ziaul H. Rana also contributed to the project.

"Our study supports a potential need for further research in understanding unhealthful dietary behavior and physical activity which may be related to loneliness, an emotion that impacts many college students," says Jiang.

Sedentary (19.2%) and low active (53.8%) behaviors were more frequent in students reporting high loneliness (score ranges of 4-6 and 7-9) than those reporting low loneliness (score of 10-12). Students reporting more loneliness had higher fat diets than students reporting less loneliness.

"Interventions to reduce loneliness may have a positive effect on health promotion in this population. This data go along with other initial findings from the Health Starts Here study that college students are not meeting healthy dietary guidelines or getting enough physical activity," said Cheskin, who has an MD.

The study is a cross-sectional study that analyzed baseline data collected in the first wave of Mason: Health Start Here in 2019, and was funded by George Mason University's Institute for BioHealth Innovation.

"Loneliness is associated with unhealthful dietary behaviors and physical inactivity among US college students," was published in November 2022 in the Journal of American College Health.

Mason: Health Starts Here is a first-of-its-kind transdisciplinary student cohort study to understand and improve the health and well-being of university students. This research will follow a broad sample of young adults, specifically Mason students, over time to capture the diversity of their experiences in college and how it affects their health and well-being.

https://www.sciencedaily.com/releases/2023/01/230120131311.htm