560-610 minutes of exercise a week needed for substantial heart benefits

 

Current exercise guidelines are too low, suggest researchers; Less fit individuals need to do more exercise to get the same benefits

Adults should aim to do between 560 and 610 minutes a week of moderate to vigorous physical activity to achieve a substantial reduction in the risk of heart attacks and stroke, suggest the findings of an observational study published online in the British Journal of Sports Medicine.

This is between 3-4 times higher than the current public health recommendation that adults do at least 150 minutes a week of moderate to vigorous physical exercise such as brisk walking, running or cycling.

People who are less fit need to do slightly more exercise than those who are very fit to get the same cardiovascular benefits, the study suggests.

The researchers say that the current one-size fits-all advice on exercise may need to be changed and replaced with personalised targets according to an individual’s fitness level.

Cardiorespiratory fitness varies greatly and is a strong predictor of cardiovascular health. Low cardiorespiratory fitness is strongly associated with an increased risk of heart attacks, strokes and early death, the researchers point out.

A simple way to assess cardiorespiratory fitness is by measuring VO2 max - the maximum rate of oxygen the body consumes and uses during intense exercise. This measures how efficiently the heart, lungs and muscles deliver and use oxygen.

Researchers from Macao Polytechnic University, China, set out to look at how both exercise levels and cardiorespiratory fitness, as measured by VO2 max, affected the risk of cardiovascular disease.

The study included data from 17 088 people who were taking part in a UK Biobank study between 2013 and 2015. The average age was 57 years and 56% were female and 96% were white.

The study participants wore a device on their wrist for seven consecutive days to record their typical exercise levels and had completed a cycle test to measure their estimated VO2 max.

Data on smoking status, alcohol intake, self-related health and diet, body mass index, resting heart rate and blood pressure were also included in the analysis.

During an average follow up period of 7.8 years, there were 1233 cardiovascular events, including 874 atrial fibrillation, 156 myocardial infarction, 111 heart failure and 92 stroke events.

Those adults who met the 150 minute a week guideline on exercise experienced a modest 8-9% reduction in cardiovascular risk, the study found. This was consistent across all levels of fitness.

In order to achieve substantial protection, classed as a greater than 30% risk reduction, between 560 and 610 minutes of moderate to vigorous exercise a week was needed. However, this level of exercise was only achieved by 12% of people in the study.

The analysis found that those individuals with the lowest fitness needed approximately 30-50 additional minutes per week compared with those with high fitness to achieve equivalent benefits.

For example, to achieve a 20% reduction in the risk of cardiovascular events, 370 minutes of moderate to vigorous exercise was needed for those at the lowest fitness compared to 340 minutes for those at the highest fitness levels.

The researchers say, "This finding highlights the steeper challenge faced by deconditioned populations.”

This is an observational study and as such no firm conclusions can be drawn about cause and effect. The researchers acknowledge that the study group could have been healthier and fitter than the general population. Another limitation was that cardiorespiratory fitness was estimated and sedentary time or less vigorous exercise was not measured.

The researchers say their findings confirm that current guidelines provide a robust universal minimum for cardiovascular protection. But they add that there should be stratified advice to help guide motivated patients to do more to protect their heart health.

“Future guidelines may need to differentiate between the minimal moderate to vigorous exercise volume required for a basic safety margin and the substantially higher volumes necessary for optimal cardiovascular risk reduction,” they conclude.

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Sex differences in dementia risks reveal stronger cognitive impacts in women

 

Researchers from the University of California San Diego School of Medicine found that women not only experience a higher burden of certain modifiable dementia risk factors, but also appear more vulnerable to their effects on cognitive function. The study, which analyzed data from more than 17,000 middle-aged and older adults, was published on May 19, 2026 in Biology of Sex Differences.

“Looking beyond which risk factors are most common, we found that some have a disproportionately larger impact on women’s cognition,” said Megan Fitzhugh, PhD, assistant professor of neurosciences at UC San Diego School of Medicine and first author of the study. “This suggests that prevention efforts may be more effective if they are tailored not just to risk factor prevalence, but to how strongly each factor affects cognition in women versus men.”

Dementia, including Alzheimer’s disease, affects women at higher rates than men, a disparity that has drawn increasing scientific attention. In fact, of the seven million adults living with Alzheimer’s disease, nearly two-thirds are women. While women tend to live longer, longevity alone does not fully explain the difference in Alzheimer’s outcomes. Researchers are now examining how combinations of biological, social and lifestyle factors contribute to this imbalance — particularly those that can be modified over time.

In the new study, Fitzhugh and Judy Pa, PhD, professor of neurosciences at UC San Diego School of Medicine and corresponding author of the study, evaluated 13 established, modifiable dementia risk factors using data from the Health and Retirement Study, a nationally representative cohort of U.S. mid- to late-life adults. These factors included education level, hearing loss, smoking, alcohol use, obesity, depression, physical inactivity, and cardiometabolic conditions such as hypertension and diabetes.

The analysis revealed clear sex-based differences in prevalence of these risk factors. Women were more likely than men to report: 

• Depression (nearly twice as common in women as men — 17% vs. 9%)
• Physical inactivity (48% vs. 42%)
• Sleep problems (45% vs. 40%) 

Women also had slightly lower average educational attainment — a known risk factor for later-life cognitive decline.

Men, on the other hand, had:

• Higher rates of hearing loss (64% vs. 50%)
• Diabetes (24% vs. 21%)
• Heavy alcohol use (22% vs. 12%) 

Hypertension was common in both groups, affecting about six in 10 participants, while average body mass index in both sexes fell in the overweight-to-obese range.

Beyond prevalence, the study found that several risk factors were more strongly associated with poorer cognitive performance in women. For example, cardiovascular and metabolic conditions such as hypertension and increased BMI showed steeper negative associations with cognition in women compared to men. However, hearing loss and diabetes — both more common among men — were linked to poorer cognitive scores in women.

These findings suggest that the same risk factor may not carry equal meaning across sexes. A condition that is moderately associated with cognitive decline in men may have a substantially stronger effect in women, amplifying its overall contribution to dementia risk.

“These differences highlight the importance of considering sex as a key variable in dementia research,” said Pa. “Sex differences are profoundly overlooked among many leading causes of death like Alzheimer’s, heart disease and cancer.”

The study’s results align with a broader push toward precision medicine — developing prevention and treatment strategies tailored to individual characteristics, including sex. Rather than focusing solely on the most common risk factors in the population, the findings suggest it may be more effective to prioritize those with the strongest cognitive impact within each group.

The researchers emphasize that these risk factors are modifiable, offering actionable opportunities for intervention. For example, this could mean placing greater emphasis on managing depression, increasing physical activity and improving cardiovascular health — such as untreated hypertension — among women, as these factors are strongly associated with cognitive health.

Looking ahead, Fitzhugh and Pa call for further research to better understand the biological and social mechanisms driving sex-based differences in Alzheimer’s risk factors. Hormonal influences, genetic susceptibility and disparities in health care access may all play a role, but more work is needed to clarify how they interact over time.

“Ultimately, a more nuanced understanding of these differences could help us design smarter, more targeted interventions,” Fitzhugh said. “That’s an essential step toward reducing the burden of dementia for everyone, but especially for women, who are disproportionately affected.”

Link to full study: Sex differences in modifiable risk factors of dementia and their associations with cognition. 

Healthy eating improves memory, but sugary diets may cause lasting damage

As concern grows about the long‑term health effects of modern diets, new research led by the University of Technology Sydney (UTS) has examined how changes in what we eat affect memory and brain function.

Published in Nutritional Neuroscience, the study focuses on whether memory function can recover after diets high in fat and sugar are replaced with healthier nutrition.

To address this question, researchers analysed evidence from controlled experiments in rodents to examine what happens to cognitive function when animals fed high‑fat and high‑sugar diets are returned to healthier nutrition.

“Our results show that improving diet quality does benefit memory,” said Dr Simone Rehn, lead author on the study.

“But those improvements were incomplete. Even after weeks on a healthy diet, memory did not return to the level seen in animals that had never eaten an unhealthy diet.”

To look beyond the results of individual studies, the researchers conducted a systematic review and meta‑analysis of 27 preclinical studies to identify consistent patterns across experiments. The analysis focused on memory, but also looked at anxiety- and depression-like behaviour, general activity, and motivation for food.

Across the studies, animals switched to a healthy diet performed better on memory tasks than those that continued eating unhealthy food. However, memory recovery depended on diet composition, with recovery seen in experiments that used high‑fat diets but not those using diets high in sugar or combined high‑fat and high‑sugar diets.

No consistent improvements were seen for anxiety, activity levels or food motivation, suggesting the effects were specific to memory rather than general behaviour.

“We saw clearer memory improvements after high‑fat diets were replaced with healthy food,” Dr Rehn said.

“But diets high in added sugar, including diets high in both fat and sugar, showed little evidence of recovery. This suggests sugar may be a key factor in limiting memory recovery.”

The memory tasks analysed reflect function of the hippocampus, a brain region essential for learning and memory, and one that is also involved in regulating appetite and food intake.

Dr Mike Kendig, senior author of the paper, said animal models were critical for understanding how diet affects the brain.

“In humans, changes in diet usually occur alongside changes in exercise, mood and daily routines, which makes it very difficult to separate the effects of diet alone on brain function.”

“There is a common belief that the effects of unhealthy eating are easily reversible,” Dr Kendig said.

“These results suggest that, at least for memory, the picture may be more complicated, especially when diets are high in added sugar.”

“Improving diet quality is still worthwhile,” he said. “But protecting brain health may also depend on avoiding prolonged exposure to unhealthy diets, rather than assuming the effects can always be fully undone later.”

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Journal

Nutritional Neuroscience

DOI

10.1080/1028415X.2026.2664635 

New report highlights differences between healthy and unhealthy ultra-processed foods

 A new report underscores the significant variations in healthfulness of different types of processed foods. The report, released by Healthy Eating Research (HER), recommends that “healthy” ultra-processed foods be exempt from policies meant to discourage consumers from eating them. 

“Many people have been told to avoid processed foods, but the science is clearly telling us that we need to be more nuanced,” said Noah Praamsma, registered dietitian with the Physicians Committee for Responsible Medicine, a national health advocacy nonprofit. “Processed meat like bacon, hot dogs, and deli meat should absolutely be avoided, but many plant-based foods that are considered ultra-processed, like breads, cereals, and meat alternatives are actually good for your health.” 

Plant-based foods, Praamsma said, even when ultra-processed, like breakfast cereal, tend to have beneficial effects on human health. Animal-based ultra-processed foods and sugary drinks are consistently found to be harmful.

The HER report’s release coincides with the federal government’s efforts to define ultra-processed foods (UPFs). The Food and Drug Administration and the U.S. Department of Agriculture began seeking input regarding a definition for UPFs last year. This definition, still pending, will be used to inform policy, including taxation, advertising limits, and what foods can be served as part of the National School Lunch Program and other government-run food service facilities.  

“We need polices informed by science, not ideology, and that are robust enough to actually promote beneficial food and discourage unhealthy foods,” Praamsma said.

Research has shown that not all foods classified as ultra-processed are harmful to health. A recent analysis from Harvard researchers found that sugary and artificially sweetened drinks and processed meats increased the risk of heart disease, but that bread, cold cereals, even some savory snacks, had beneficial effects.

The bread and cereal UPF categories, as well as plant-based meat alternatives, have also been found to reduce the risk of type 2 diabetes, compared to processed meat and sugary drinks, which increased risk of diabetes and heart disease.

The 14-member committee that authored the HER report recognized certain criteria should be used to exclude UPFs that are known to be healthy. Foods fall into this category if they contain adequate amounts of recommended food groups; remain below nutrient thresholds for added sugar, sodium, and saturated fat; and do not contain non-sugar sweeteners. 

The HER report aligns with growing scientific consensus that not all UPF subgroups may have drastically different effects. In August of 2025, the American Heart Association acknowledged that “not all UPFs are junk foods or have poor nutritional quality; some UPFs have better nutritional value and can be part of an overall healthy dietary pattern.” 

Grape consumption = improved skin health

Clinical trials have shown that consumption of grapes can increase the resilience of skin to UV irradiation in about 30-50% of the subject population. New studies published in the current issue of the journal ACS Nutrition Science suggest the effect of consuming grapes on human skin health is much broader – most likely affecting everyone. 

The investigation was performed with human volunteers who consumed the equivalent of three servings of whole grapes each day for two weeks. Gene expression in skin was determined before and after grape consumption, with and without exposure of skin to low doses of UV irradiation. 

The results demonstrated inter- and intraindividual differences of gene expression in the skin. In other words, from the outset, gene expression in the skin of each individual was different. The expression changed when the subjects consumed grapes or when exposed to UV irradiation, but still each individual was different from one another. Further unique changes were observed when UV irradiation was combined with grape consumption. 

Consequently, while gene expression is different when comparing one person to another person, the gene expression of every person changed after consuming grapes. 

When searching for a functional commonality resulting from these changes in gene expression after consuming grapes, the investigators were able to construe the myriads of data as being indicative of enhanced skin keratinization and cornification, which are known to create a  barrier against environmental damage. This idea was reinforced by exposing skin to a low dose of UV irradiation and measuring the generation of malondialdehyde, a marker of oxidative stress, which was reduced when the subjects consumed grapes. 

 “We are now certain that grapes act as a superfood and mediate a nutrigenomic response in humans,” said John Pezzuto, Ph.D., Professor and Dean of the College of Pharmacy and Health Sciences at Western New England University. “We observed this with the largest organ of the body, the skin. The changes in gene expression indicated improvements in skin health. But beyond skin, it is nearly certain that grape consumption affects gene expression in other somatic tissues of the body, such as liver, muscle, kidney and even brain. This helps us to understand how consumption of a whole food, in this case grapes, affects our overall health. It’s very exciting to be working in the post-genomics era where we can finally start to employ functional genomics and actually visualize complex matrices indicative of nutrigenomic responses.” 

Improved life satisfaction linked to being in nature

 

A major international study has found that contact with the natural world is linked to higher levels of life satisfaction – and we have our bodies to thank for unlocking this benefit.

Published in the journal Environment International, the research analysed responses from 50,363 people aged 18 to 99, from across 58 nations, making it the largest multinational study of its kind ever carried out.

It is known that spending time in a nature can improve our mental wellbeing, but the mechanisms underpinning these benefits have not been fully understood.

This new study, led by Viren Swami, Professor of Social Psychology at Anglia Ruskin University (ARU), has discovered that contact with nature helps people develop more positive body image, and it is this increased “body appreciation” that is responsible for greater life satisfaction. Crucially, these findings apply to all ages and gender identities.

The link between spending time in nature and positive body image itself is underpinned by two pathways. First, the research demonstrates that nature contact is associated with higher self-compassion, which in turn promotes greater body appreciation and life satisfaction.

Nature provides opportunities for what psychologists describe as “cognitive quiet”, which is a state of awareness where our attention is effortlessly engaged. The gentle sights and sounds of natural environments allow deliberation without mental strain, which helps people to display kindness towards themselves.

A second pathway identified in the study focuses on how spending time in nature helps people feel restored. Busy urban environments often require constant focus to manage competing demands such as traffic, noise and crowds, which can lead to mental fatigue.

In contrast, tranquil natural environments encourage mindful thinking and help the brain recover. The study found that feeling restored after spending time in nature is also associated with greater body appreciation, which in turn results in greater life satisfaction.

Lead author Professor Viren Swami of Anglia Ruskin University in Cambridge, England, said: “We know that spending time in nature is good for our mental and physical health, but this study highlights one important way in which those benefits translate into greater life satisfaction.

“In particular, our findings highlight how being in nature is linked to greater self‑compassion and a stronger sense of restoration. Both of these are associated with more positive body image and, ultimately, improved life satisfaction.

“What is striking is how consistent these patterns are across countries, ages and gender identities, suggesting that connecting with nature helps people build positive relationships with their bodies in ways that are deeply rooted in human psychology.

“At a time when many countries are searching for affordable ways to improve wellbeing, our findings highlight the value of natural environments as important public health resources and reinforce the importance of using scientific evidence to shape planning, education and health policies.”

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Journal

Environment International

DOI

10.1016/j.envint.2026.110277 

Too little sleep—and too much—associated with faster aging

An analysis of biological clocks throughout the human body suggests that too few hours of sleep—and too many—may speed aging in the brain, heart, lung, and immune system and is associated with a wide range of diseases. 

“Previous studies have found that sleep is largely linked to aging and the pathological burden of the brain. Our study goes further and shows that too little and too much sleep are associated with faster aging in nearly every organ, supporting the idea that sleep is important in maintaining organ health within a coordinated brain-body network, including metabolic balance and a healthy immune system,” says study leader Junhao Wen, assistant professor of radiology at Columbia University Vagelos College of Physicians and Surgeons. 

The research was published May 13 in Nature. 

The power of aging clocks 

Aging clocks are increasingly popular for digitizing how many years a person ages faster or slower than their chronological age using machine learning, based on the biological data (e.g., proteins from a minimally invasive blood test) from the person.  

Though most aging clocks measure aging across the whole body, organs age at different rates—a fact well-known to women facing ticking biological clocks due to fast-aging ovaries.  

Wen’s group has been at the forefront of constructing aging clocks for specific organs in the body that could provide more specific and personalized information to patients.  

“Everyone is excited by these aging clocks and their ability to predict disease and mortality risk,” Wen says. “But to me, the more exciting question is, can we link aging clocks to a lifestyle factor that can be modified in time to slow aging?” 

The U-shaped pattern between aging clocks and sleep 

Sleep was the perfect test case, as sleep is increasingly thought to be an important factor in health. “I’m also a light sleeper and was getting worried about the effects on myself,” says Wen.  

To build his aging clocks, Wen used data collected from half a million participants in the UK Biobank and used machine learning to determine signatures for an aging organ. Wen used a wide variety of data sources to create aging clocks based on structural data from medical images, organ-specific proteins, and molecules found in blood in each organ. “In the liver, for example, we have an aging clock built with protein data, an aging clock of metabolic data, and an aging clock of imaging data,” Wen says. “This allows us to see whether sleep is distinctively associated with aging clocks derived from multiple omics and molecular layers.” 

He then assessed the relationship between a person’s sleep duration (as reported by each Biobank participant) and their biological ages from 23 aging clocks across 17 organ systems.  

Across the entire body, a coordinated U-shaped pattern emerged: In the UK Biobank population, both short sleep (fewer than 6 hours) and long sleep (greater than 8 hours) were associated with faster aging, while the least amount of aging occurred in people who reported between 6.4 and 7.8 hours of sleep per day. This does not mean that sleep duration alone causes organs to age faster or slower, but it suggests that both insufficient and excessive sleep may be markers of poorer overall health across the body. 

Sleep’s body-wide connection to disease 

The relationship between sleep and disease suggests that there exists a connection between the brain and the body that extends beyond merely influencing the brain itself.  

Among brain-related disorders, short sleep was significantly associated with depressive episodes and anxiety disorders, as seen in other studies of sleep and mental health. Short sleep was also associated with obesity, type 2 diabetes, hypertension, ischemic heart disease, and heart arrhythmias. Short and long sleep were associated with chronic obstructive pulmonary disease, asthma, and a cluster of digestive disorders, including gastritis and gastroesophageal reflux disease. 

Wen says, “The broad brain-body pattern is important because it tells us that sleep duration is a deeply embedded part of our entire physiology, with far-reaching implications across the body.” 

A deeper look at late-life depression and sleep 

Beyond predicting disease, the organ-specific aging clocks are also valuable for determining how sleep is related to specific conditions, as exemplified by Wen’s examination of late-life depression.  

Although the study could not definitively determine if sleep duration caused late-life depression or if late-life depression impacted sleep duration, Wen’s group applied “mediation analysis” to late-life depression, asking whether aging clocks mediate the relationship between both short and long sleep and late-life depression. The analyses suggest that short sleep may act directly on the disease burden of late-life depression, while long sleep may impact late-life depression via a mediation pathway underlying the brain and adipose clocks. 

“This has a strong implication for future sleep management and future therapeutics,” Wen says. “Our study suggests there may be different biological pathways between long and short sleepers that lead to the same outcome, late-life depression, and we shouldn’t treat them the same way.”