Heavy TV watching associated with smaller brain structures,

Reduced volume was found in areas of the brain connected to memory formation, indicating a potential link between TV watching and higher dementia risk

Turn off that TV, it’ll rot your brain!” has been a household refrain for decades. While “rot” might be too strong a term, researchers are finding that the overall sentiment could have some merit.

A study published recently in Alzheimer’s and Dementia: Journal of the Alzheimer’s Association revealed that those who reported watching TV “very often” in midlife later exhibited reduced volume in areas of the brain associated with memory, smaller frontal and occipital lobes, and areas of damage in the brain’s white matter that are associated with aging, stroke risk, cognitive decline and dementia. 

“For years we’ve focused on how much people sit. Our findings suggest we should also pay attention to what they’re doing while they’re sitting,” says David Raichlen, professor of biological sciences and anthropology at the USC Dornsife College of Letters, Arts and Sciences and a senior author of the study. 

The findings weren’t just due to TV viewing’s sedentary nature. The study found that other types of sedentary activities did not have the same associations, indicating that what one does while sitting may matter much more than previously thought.

Watching changes

The researchers analyzed data from about 1,700 adults, average age 53, who enrolled in the Atherosclerosis Risk in Communities (ARIC) Study between 1987 and 1989. ARIC is a long-running study of the U.S. population designed to investigate cardiovascular and brain health. 

Participants were asked how frequently, on a scale ranging from “never/seldom” to “very often,” they watched television during their leisure time and how much of their workday they spent sitting.

More than two decades later, participants underwent brain MRI. Compared with people who reported “never” or “seldom” watching TV, those who watched TV “very often” showed widespread structural differences across the brain.

The researchers found smaller volumes in areas associated with early signs of Alzheimer’s disease and more white matter hyperintensity volumes, an indicator of cerebral small blood vessel disease associated with cognitive decline and dementia. These participants also had smaller occipital and frontal lobes, regions associated with visual processing and executive functioning.

Differences persisted even when the researchers controlled for factors such as physical activity, diabetes, body mass index, smoking, and alcohol use.

Of note, the researchers relied on self-reported data for TV consumption, which can be less precise than timed tracking. Study participants also did not undergo a baseline MRI. Future research could begin with a baseline MRI to more concretely demonstrate changes over time.

Not all sitting is made the same

Strikingly, the sedentary element of TV watching didn’t appear to be the main driver for these changes.

Those who reported high amounts of sitting at work actually had larger frontal and occipital lobes, as well as reduced white matter hyperintensity volumes, indicating better brain health than among those who sit to watch TV. This could be due to the intellectually stimulating nature of many sit-down jobs, say the study authors. 

Men appeared to be particularly vulnerable to these changes. When the MRI scans were separated by sex, researchers found that most of the changes to the brain, both from TV watching and occupational sitting, were seen in men.

Such findings indicate there is still more research to be done on this complex topic. However, we might eventually see a different approach to health guidance around sedentary activities. Rather than just directing their patients to move more, for example, physicians might recommend they reduce television time and add cognitively engaging activities for when they do sit.  

“We frequently encourage the public not to spend too much time sitting down, but experts may want to expand that recommendation to encompass the activities done while sitting, since those seems to have distinct impacts on brain health,” says study corresponding author Natan Feter, postdoctoral scholar in the Human and Evolutionary Biology program at USC Dornsife. 

 

Common diet tips about water intake and spicy foods could be wrong

  The common rationale for drinking water at meals is that it physically stretches the stomach, triggering fullness so you don’t eat too much. 

But a new Cornell study found no support for that idea in practice. 

Instead, for every additional 100 grams of water participants drank, they ate about 39 more grams of food – roughly 49 more calories. People who frequently switched back and forth between bites of food and sips of water ate even more: each additional switch was tied to about 4.4 more grams of food consumed.

Researchers suspect this “switching” effect works by delaying something called sensory-specific satiety – the way a food’s appeal naturally fades the longer you eat it. Alternating with water may reintroduce contrast that keeps the meal appealing longer, delaying the point at which people stop eating.

, Click to open gallery view

Credit:Laila Milevski/Cornell University

“There’s been this widespread advice that if we drink water, it fills us up,” said Paige Cunningham, assistant professor in the Division of Nutritional Sciences in the College of Human Ecology. “But water is emptied quickly from the stomach so it likely doesn’t fill us up for long. Instead, water may increase how much we eat, providing lubrication which can speed up eating, and preventing a dry mouth which can prolong enjoyment of the food.”

Cunningham is the corresponding author on the new analysis, published in July in the journal Appetite and conducted with longtime collaborator John Hayes of Penn State’s Department of Food Science. In a second related study, the researchers measured the effect of spicy salsa on eating volume – and again found a surprising result.

“Both studies show how mealtime behaviors and food properties can significantly influence how much we eat, without us even realizing. We found that just drinking more water was associated with greater consumption, while adding a bit more spice to a snack slowed eating and decreased how much participants ate,” said Cunningham.

The drinking water study pooled data from two earlier lab experiments, 86 adults in all, who ate as much as they wanted of a lunch (either beef chili or chicken tikka masala) served with water, while researchers recorded every bite and sip on video.

One result cut against the researchers’ own expectations: Participants who drank water faster during a meal ended up eating less, not more. The paper offers this as a genuine open question rather than a settled explanation, noting it may reflect how long water sits in the mouth, or may simply track with how long a meal lasts overall. 

“This was a secondary analysis looking at associations,” Cunningham said. “We are following up on this right now so we can make those causal inferences.”

In a separate experiment, whose results published April in Food Quality and Preference, 49 adults were served tortilla chips alongside a mild or spicy salsa, once a week for two weeks; only the salsa’s cayenne content changed between conditions. The spicier version cut total snack intake by 28% – not just of the salsa itself, but of the chips too, even though the chips themselves didn’t change.

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Credit:Laila Milevski/Cornell University

Participants ate the spicy snack about 30% more slowly than the mild one, which the researchers suspect drove the decrease: Heat slowed people down, and slower eating meant less eaten overall. Water intake during the snack was unaffected by spice level, which the researchers note rules it out as an explanation for the reduced intake.

“We were interested in whether making the salsa spicy would result in people eating the same amount of chips,” Cunningham said. “And they didn’t. The takeaway is that adding spice to one part of the snack can significantly influence how much people eat overall.”

Read together, the two papers make a case that runs against two different strands of popular nutrition advice at once: that water at meals is a simple ally in eating less, and that spicy food is something to approach with caution if you're watching what you eat. This research showed the opposite might be true: water tracked with eating more, and spice tracked with eating less.

“These strategies might help consumers achieve their goals to reduce energy intake,” Cunningham said. 

Both papers are explicit about their limits: the meals and snacks tested were a narrow set – chili, tikka masala and one chip-and-salsa combination – all eaten in a controlled lab setting, and the researchers caution against assuming the same patterns would hold for very different foods or in everyday, uncontrolled eating.

“We are looking to future experiments that explore what other factors or properties of foods can we leverage to influence behaviors,” Cunningham sai

Many women still confused about perimenopause

Perimenopause is an underrecognized life stage that is often accompanied by complex and fluctuating symptoms. A new study sought to quantify the prevalence of perimenopause uncertainty and identify the primary causes. It found that perimenopause uncertainty is prevalent and largely because of knowledge gaps and barriers to confirmation and care. Results of the study are published online today in Menopause, the journal of The Menopause Society.

Perimenopause is the transitional period leading up to the final menstrual period. Known as a time of considerable hormone changes, it usually begins when women are aged in their mid-40s, although onset can vary widely. It is estimated that approximately two million women begin perimenopause each year in the United States and remain in this phase for roughly 4 to 8 years.

Perimenopause symptoms can significantly affect women’s well-being, with more than half (59%-65%) experiencing hot flashes as well as psychological or urogenital symptoms that can impair daily functioning, diminish quality of life, and reduce work productivity. Despite its prevalence, recognizing perimenopause remains a challenge for both women and clinicians. A key reason is that there is no laboratory test or biomarker to definitively determine the perimenopause stage. Complicating a clear diagnosis is the fact that perimenopause symptoms vary widely and evolve over time. These symptoms also overlap with a wide range of other conditions, including premenstrual syndrome, thyroid disease, and mental health conditions.

Limited public awareness and inconsistent clinical recognition further compound this uncertainty. Many women report little prior knowledge about perimenopause, and clinicians typically receive inadequate training and education on perimenopause and menopause care. In addition, there has been a propagation of misinformation about menopause and symptom management in recent years.

Prior studies have described elements of perimenopause uncertainty, such as confusion about symptoms, misconceptions about the age at which symptoms might occur, and invalidating healthcare encounters, but most were small, focused only on women aged older than 40 years and were rarely US based. In addition, there is no known study to have quantified how common perimenopause uncertainty is, what its common drivers are, and whether those drivers differ across age groups or levels of symptom burden.

In this new study involving more than 7,600 US women aged 35 years and older, researchers sought to estimate the prevalence of perimenopause uncertainty and examine subgroup differences by age and symptom severity. Overall, 34% of participants reported being unsure of their reproductive stage. Uncertainty varied by age and symptom severity, peaking at 42% in those aged 40 to 44 years, and 37% in those with severe symptom burden.

Symptom confusion and attribution were the most common (56%), reflecting difficulties interpreting bodily changes and distinguishing perimenopause from other causes. Knowledge gaps and information-seeking accounted for 28% of responses, highlighting limited health literacy, age-based assumptions, and active searches for evidence. Barriers to confirmation and care (16%) described dismissive healthcare encounters and reluctance to acknowledge perimenopause. Younger women (aged 35-39 y) were more likely to cite knowledge gaps, whereas healthcare barriers peaked in the 40 to 44-year-old age group.

Based on these results, the researchers recommend that clinicians should be more open and flexible to consider the multidimensional symptom profiles of perimenopause and normalize cognitive, emotional, and physical changes that can occur earlier rather than over-relying on menstrual irregularity as the principal indicator. Although cycle irregularity is characteristic of perimenopause, many women have symptoms before they experience significant cycle changes.

Survey results are published in the article “Exploring prevalence and drivers of perimenopause uncertainty among US Women: a mixed-methods study.”

“This large study showed that one in three US women aged older than 35 years are not sure whether they are in perimenopause. Further, the study highlights that symptom confusion, misconceptions, and barriers to care are leaving many women without the clarity and support they need during the menopause transition. Recognizing perimenopause uncertainty as a common experience can help shift the conversation from searching for a diagnosis to providing women with the information, validation, and support they need to navigate this natural life transition with confidence,” says Dr. Stephanie Faubion, medical director for The Menopause Society and one of the authors of the study.

For more information about menopause and healthy aging, visit www.menopause.org. 

Loneliness strongly linked to poorer mental health and wellbeing

 

People who feel lonely are much more likely to experience poorer mental health and lower wellbeing, a new collaborative study led by the University of Bristol, Nesta and Amsterdam UMC has found. Loneliness was also found to be linked with worse general health, including experiencing multiple health conditions. Social isolation is associated with lower wellbeing, too.

Loneliness is increasingly recognised as a major public health issue, with growing evidence connecting it to poorer health. However, it is unclear whether loneliness itself contributes to poor health or whether these links are driven by other factors.

The study, in association with the universities of Oxford and Manchester, combined evidence from three different research methods, including observational analysis, sibling comparisons, and Mendelian randomisation, a genetics-based approach, to build a clearer understanding of these relationships.

Using data from the UK Biobank and large-scale genome-wide association studies, the researchers investigated how both loneliness - the quality of a person's social relationships; and social isolation - the number of social connections, relate to health and wellbeing. The study is published in Nature Communications today [15 July].

The research team found that loneliness and social isolation are linked to poorer mental health and reduced wellbeing, with loneliness also associated with worse general health. While the study found no clear evidence of effects on specific physical health conditions, these potential impacts cannot be ruled out.

The findings suggest that loneliness, and potentially social isolation, remain important public health issues, particularly because of their links with mental health, wellbeing and overall health.

As loneliness becomes an increasingly important public health challenge, tackling it could bring benefits for both individuals and society.

Dr Zoe Reed, Research Fellow in the School of Psychology and Neuroscience at the University of Bristol, and corresponding author, said: “Our findings suggest that loneliness, and possibly social isolation, are still important public health concerns, especially for mental health and general health. Supporting people who feel lonely or socially isolated could help improve mental health, wellbeing and overall health.”

Lauren Bowes Byatt, Director of Nesta’s healthy life mission, added: “This research underlines that loneliness is likely to have a detrimental impact on our mental health and wellbeing. While this link may seem obvious, the topic has long been understudied. Studies like this can help to bridge this research gap and by understanding how loneliness or social isolation may be contributing to ill-health, we can get closer to new and more effective solutions.”

The researchers suggest more research is needed to understand exactly how loneliness and social isolation affect health and to develop the most effective ways to reduce their impact.

As the study focused on middle-aged and older adults, future studies should explore whether these patterns are similar in younger people. It will also be important to investigate the effects of persistent or long-term loneliness, as the study measured loneliness at a single point in time.

The paper’s findings add to growing evidence that loneliness and social isolation are not just social issues, they are important public health concerns with wide-ranging implications for wellbeing and mental and physical health. The research reinforces the importance of addressing these issues as part of public health policy and practice.

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Journal

Nature Communications

DOI

10.1038/s41467-026-74758-7 

Dementia risk may be reduced through diet

 Natural plant compounds known as polyphenols, found in berries, tea, cocoa, coffee, and extra virgin olive oil, may positively influence biological processes linked to Alzheimer’s disease and other disorders characterized by the gradual loss of nerve cells, according to a review by researchers at Semmelweis University. The analysis, published in Nutrients, suggests that these bioactive compounds may contribute to healthy brain aging.

Researchers at Semmelweis University reviewed the findings of hundreds of previous laboratory, animal, population-based, and clinical studies. The studies reviewed suggest that polyphenols may support nerve cell function through their antioxidant and anti-inflammatory properties while helping counteract harmful processes associated with brain aging. 

Particular attention has been paid to the Mediterranean diet, which is rich in vegetables, fruits, legumes, whole grains, fish, and olive oil, as well as the MIND diet, which is based on Mediterranean dietary principles. The MIND diet was specifically developed to support brain health by emphasizing leafy green vegetables and berries while limiting the consumption of red meat, butter, cheese, sweets, and fried and fast foods.

Among the compounds frequently examined in the reviewed studies were EGCG, one of the main antioxidants found in green tea; the pigments responsible for the color of berries; flavanols found in cocoa; and curcumin, the compound that gives turmeric its characteristic yellow color. These compounds are commonly found in plant-based diets, including the Mediterranean diet. 

“Polyphenols are not miracle cures, but research suggests they may be promising tools for supporting healthy brain aging. The focus, however, should not be on dietary supplements but on a varied diet rich in plant-based foods,” said Dr. Mónika Fekete, Assistant Professor at the Institute of Preventive Medicine and Public Health of Semmelweis University and senior author of the study. 

A substantial proportion of polyphenols is not absorbed directly. Instead, they are transformed by bacteria living in the gut into compounds that may influence inflammatory processes, cellular energy metabolism, and, through these mechanisms, nervous system function. Because the composition of the gut microbiome varies considerably from person to person, the same foods may not produce identical biological effects in everyone.

“This may help explain why the same diet does not affect everyone in the same way. In the future, personalized nutrition could help us better understand who is most likely to benefit from a polyphenol-rich diet,” said Dr. Noémi Mózes, Assistant Professor at the Institute of Preventive Medicine and Public Health of Semmelweis University and first author of the study. 

According to the World Health Organization (WHO), more than 55 million people worldwide are living with dementia, and that number is expected to rise in the coming decades. Dementia is one of the most significant health challenges associated with aging, which is why growing attention is being paid to lifestyle factors – including diet – that may help maintain brain health and reduce the risk of cognitive decline.

The researchers emphasize that despite encouraging findings from human studies, there is currently insufficient evidence to recommend any single food or nutrient as a stand-alone strategy for preventing dementia.
According to the authors, healthy brain aging depends not on any one “superfood” but on long-term eating habits. In other words, there is currently no miracle diet that can prevent Alzheimer’s disease. However, existing evidence suggests that regularly eating more vegetables, fruits, berries, fiber-rich foods, fish, and nuts while limiting highly processed foods may help support healthy brain aging and preserve cognitive function over time.  

Nature’s Hidden Bioactive Compounds
Bioactive compounds, including polyphenols, are naturally occurring substances found in plants, animals, and microorganisms. Although they are not considered essential nutrients like vitamins or minerals, their biological activity may help support normal bodily functions and overall health.

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Journal

Nutrients

Eating an avocado a day lowers heart disease risk factor for people with obesity

 

 Eating an avocado every day may decrease heart disease risk in adults with obesity, according to a recent study led by researchers in the Penn State Department of Nutritional Sciences and published in the Journal of Clinical Lipidology.

The team found that regular avocado consumption was associated with a reduced concentration of low-density lipoprotein (LDL) particles — proteins that transport cholesterol through the body — in the blood by an amount that corresponds to an approximate 4% reduction in heart disease risk.

“If people want to improve the quality of their diet, making one small change might be a more feasible strategy than attempting to change their entire diet,” said Janhavi Damani, postdoctoral scholar at Penn State and first author of the study. “For people with obesity, including avocados in their daily diet might be a good starting place.”

LDL particles are a separate risk factor for heart disease from LDL cholesterol — the so-called “bad cholesterol” that is a significant risk for heart disease. The risk posed by LDL particles is typically higher in people with abdominal obesity, the researchers said.

LDL cholesterol must be transported through the body by a protein particle. When there are more protein particles carrying LDL, this increases the risk for heart disease, even if the amount of cholesterol remains the same.

“Imagine two people with the same high levels of LDL cholesterol,” Damani said. “Person A carries their cholesterol in fewer, larger LDL particles, and Person B carries their cholesterol in more, smaller LDL particles. Person B’s heart disease risk would be higher because their overall particle count is higher even though a test of their LDL cholesterol would look identical.”

These small particles can more easily penetrate artery walls and contribute to build-up on artery walls known as plaque, Damani explained. Plaque contributes to heart disease risk by restricting the amount of blood that can fit through a blood vessel and reducing the blood vessel’s flexibility. This means that when a person’s heart is working the hardest — due to exertion, heat, stress or any reason — their blood pressure will increase more because the blood vessel is unable to compensate for the increased load, which can trigger a cardiac event like a heart attack.

In this study, the researchers analyzed data originally collected from 786 participants in the Habitual Diet and Avocado Trial, a six-month study of adults 25 years and older. Men were eligible for the study if they had a waist circumference greater than 40 inches, and women were eligible if they had a waist circumference greater than 35 inches.

Half of the participants were instructed to maintain their normal diet and activity. The other half were provided with one avocado to consume each day and were instructed to maintain their normal diet and activity.

Researchers in the Habitual Diet and Avocado Trial found that adding avocado to the diets of people with obesity did not change weight or waist circumference, but that it could reduce levels of LDL cholesterol.

In the current study, the researchers compared blood samples taken at the beginning and end of the study. Over the course of the study, levels of LDL particles in the avocado-per-day group decreased by 49 nanomoles per liter, which corresponds to an approximate 4% reduction in heart disease risk, the researchers said.

"Four percent is a modest reduction compared with the 14–29% lower heart disease risk associated with improving the overall diet,” Damani said. “However, it is a step in the right direction."

Additionally, regardless of study participants’ sex, race, ethnicity, age or body mass index, they were equally likely to experience improvement in the LDL particle levels. This indicates that anyone with obesity could benefit from avocado consumption, the researchers explained, with the added caution that people should speak to a registered dietitian nutritionist or their physician for personalized, expert guidance on improving their diets.

“Penn State researchers demonstrated several years ago that avocado consumption could reduce LDL cholesterol and levels of LDL particles,” said Kristina Petersen, associate professor of nutritional sciences and senior author of this study. “But in that study, the researchers controlled participants’ entire diets throughout the experiment. This study demonstrated benefits in the real world, where people’s diets are much less predictable. In the course of people’s normal lives, avocado consumption still contributes to a healthier diet.”

Penny Kris Etherton, retired Evan Pugh University Professor of Nutritional Sciences at Penn State, also contributed to this research.

Other co-authors of the study include Nirupa Matthan of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University; Zhaoping Li of the David Geffen School of Medicine at University of California, Los Angeles; Joan Sabaté of the School of Public Health at Loma Linda University; and David Reboussin of the Wake Forest University School of Medicine.

The Avocado Nutrition Center supported this research.

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Journal

Journal of Clinical Lipidology

DOI

10.1016/j.jacl.2026.06.005 

Night owls are at greater risk of poor metabolic health

Whether you are an early bird or a night owl, your sleep patterns can tell a lot about a person’s eating habits and subsequently the potential health risks.

Professor Rozanne Kruger from Griffith University’s School of Allied Health, Sport and Social Work studied 287 European and Pacific New Zealand women aged between 18-45 years and assessed if they were morning chronotypes (early bird) or an evening chronotype (night owl).

“Chronotypes influences our preferences for food intake, our behaviours and our metabolism,” Professor Kruger said.

“Both Morning-types and Evening-types consumed similar amounts of food or energy across the day, but it was the timing of eating that was crucial.”

Evening-types consumed less food between 3am and 9:59am but more food between 8pm and 2:59am, while the opposite was true for Morning-types.

Night owls were more likely to consume lower energy and protein intakes in the morning, and ate foods that were high in energy, carbohydrates and fats late at night.

This Evening-type eating and sleeping pattern was associated with greater body fat percentage, belly fat, and higher blood sugar and lipids.

Consuming food at night, when we are supposed to be fasting and sleeping, means we store more food rather than use it, which may increase susceptibility to obesity and cause worse health outcomes.

Women who naturally preferred a later bedtime and wake time were also more likely to have a higher Body Mass Index and Body Fat percentage, poorer lipid profiles, and less favourable indicators of glucose regulation than Morning-types.

“The research highlights that when people eat may be just as important as what they eat,” Professor Kruger said.

“Targeting meal timing, particularly reducing late-night eating, could be an important strategy for improving health amongst people with an evening chronotype.

“It reinforces the role of chrononutrition and the role it plays in obesity and metabolic disease prevention.”

The paper ‘Chronotype and associations with dietary intake, meal timing, body composition, and metabolic biomarkers’ has been published in Frontiers in Nutrition.

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Journal

Frontiers in Nutrition

DOI

10.3389/fnut.2026.1862060