Keto diet has greater health benefits than other popular weight-loss diets,

A diet that severely limits carbohydrates but is high in fat has the greatest health benefits for people with obesity compared to a Mediterranean diet or a low-fat diet, according to a clinical trial publishing August 27 in the Cell Press journal Cell Metabolism. After following a ketogenic (or “Keto”) diet for four to five months, about 50% of a group of participants with obesity and prediabetes no longer met the criteria for prediabetes. 

“We know weight loss can improve metabolic health in people who are obese,” says Samuel Klein, the study’s corresponding author at Washington University School of Medicine in St. Louis, Missouri. “Our data suggest that if you have high liver fat content and prediabetes, reducing carbohydrate intake can have important therapeutic effects on metabolism beyond just weight loss alone.” 

It is estimated that some 40% of American adults have obesity. Healthcare providers commonly recommend low-fat, low-carbohydrate, or Mediterranean diets to promote weight loss, but it has been unclear if any of these diets provide additional metabolic benefits beyond weight loss itself, or if one offers greater health benefits than the others. 

The three popular diets differ significantly in their major nutrient composition. For example, a low-carbohydrate diet, also known as Atkins or ketogenic diet, severely restricts carbohydrate intake, while a low-fat diet can source as much as 70% of its energy from carbohydrates. A Mediterranean diet contains mostly plant-based foods, such as vegetables, olive oil, and nuts, with moderate amounts of fish and dairy, while a ketogenic diet can include foods high in saturated fat, including animal products. 

To understand the diets’ metabolic effects in people, Klein and his team conducted a clinical trial with 42 participants who had obesity, prediabetes, and fatty liver disease. The researchers randomly assigned them to one of three diet groups: a ketogenic diet, a Mediterranean diet, or a low-fat, plant-forward diet. The participants received all of their food from the research team and met weekly with a dietitian to help them adhere to their assigned diets.  

In the study, the ketogenic diet provided only 4% of calories from carbohydrates and 73% from fat. The Mediterranean diet had 50% of its calories from carbohydrates and 35% from fat. The plant-forward diet sourced 70% of calories from carbohydrates and 15% from fat. 

The team tailored each participant’s calorie intake so that everyone lost about 10% of their body weight, which took about four to five months.  

By the end of the trial, all three diets led to a significant reduction in the participants’ body fat. Their bodies also became more sensitive to insulin, improving their ability to regulate blood sugar.   

But the ketogenic diet produced the greatest improvements in several markers of liver and metabolic health. Participants’ liver fat decreased by an average of 67% in the ketogenic group, compared with 45% in both the Mediterranean and the plant-forward groups.  

When the team monitored the participants’ metabolic activities over 24 hours by testing their blood throughout, they found that the ketogenic diet group had the largest increase in glucagon, which is a hormone that promotes fat loss in the liver. That group also experienced the greatest reduction in blood insulin levels, which also reduces fat content in the liver, compared to the other two groups.  

“The most surprising finding was that participants in the ketogenic diet group didn’t experience an increase in blood fat or cholesterol levels despite consuming the most fat,” says Max Petersen, the study’s first author at Washington University School of Medicine. 

Following the weight-loss intervention, about 50% of participants in the ketogenic group no longer met the criteria for prediabetes, compared with 29% in the Mediterranean group and 7% in the plant-forward group. 

“GLP-1-based medications have revolutionized the therapy of obesity. We now have a very effective pharmacotherapy for achieving significant weight loss,” Petersen says. “But in addition, our study shows that the specific composition of the diet can give you added benefits.” 

Cell Metabolism, Petersen et al., “Effect of diet macronutrient content on the cardiometabolic response to weight loss: A randomized clinical trial” https://www.cell.com/cell-metabolism/fulltext/S1550-4131(26)00293-7 

The interpretation of the term ‘plant-based’ diet differs significantly among U.S. adults

 

 When referring to diet, the term “plant-based” has mixed interpretations among U.S. adults, and its meaning varies significantly among demographic groups, according to new research published in the American Journal of Lifestyle Medicine. 

“The term plant-based has become popular in recent years and its meaning has never been clearly defined,” explained Dr. Anna Herby, nutrition education specialist at the Physicians Committee for Responsible Medicine and co-author of the study. “The greatest benefits of a plant-based diet stem from completely avoiding animal products. As dietitians who promote this healthful dietary pattern, we wanted to understand how people interpret the terminology in order to more clearly communicate about it.”

Key findings of the study include:

• 56% said “plant-based” means vegan—avoiding all animal products.
• 35% said it means eating abundant plant foods while still eating some meat, dairy and eggs.
• 7% said they didn't know.
• 2% gave another answer.

Interpretation also varied significantly by demographic group: 63% of adults ages 65-94 equated plant-based with vegan, compared with 51% of 18-to-34-year-olds.

The study analysis drew on the results of a survey of 2,202 U.S. adults conducted in July 2025 that was designed and executed by Morning Consult following the Best Practices for Survey Research of the American Association of Public Opinion Research.

“Defining ‘plant-based’ as excluding all animal products could make it easier for consumers to make confident decisions about food products by knowing that the term means there are no animal products,” said study co-author Shannon Menhardt, MS, a registered dietitian with the Barnard Medical Center. “A consistent definition could also make research findings and dietary recommendations easier to interpret and help provide clearer messaging for health professionals, patients, and the media.”

Xylitol may increase the risk of cardiovascular events

 Key takeaways 

• A long-term analysis studied the effects of the artificial sweetener, xylitol, on cardiovascular events in the general population. 
• High blood levels of xylitol were associated with a greater risk of cardiovascular events than lower levels. 
• Further studies on the safety of xylitol and other artificial sweeteners are warranted as they continue to be used in increasing amounts. 
   

A study to be presented at ESC Congress 2026 will show that high blood levels of the artificial sweetener, xylitol, were associated with increased risk of major adverse cardiovascular events.1

 

Artificial sweeteners are widely used to replace dietary sugar. Xylitol is a sugar alcohol that occurs naturally in the body as a byproduct of glucose metabolism and is present in some natural foods in very low amounts. Xylitol is also added – often in over 1,000-fold higher amounts – to artificially sweeten foods, beverages and oral care products. Despite its growing use, the long-term impact of xylitol on cardiovascular event risk has not been widely studied. 

 

“In previous studies, we showed that xylitol can enhance the ability of platelets to form clots,2” said presenter, Doctor Marco Witkowski from the Charité University Hospital, Berlin, Germany. “We also found that high blood levels of xylitol were linked to cardiovascular events in high-risk individuals over a 3-year period.2 Here we studied if xylitol increases cardiovascular events in a larger sample of the general population over much longer follow-up.” 

 

The research team looked at data from 17,710 participants in two prospective observational cohorts: the Canadian Longitudinal Study on Aging (CLSA) and the European Prospective Investigation into Cancer (EPIC)-Norfolk.  

 

People with xylitol levels in the highest quartile were observed to have substantially higher risk of major adverse cardiovascular events (defined as death, myocardial infarction or stroke) than those with xylitol levels in the lowest quartile. 

 

Over a follow-up period of 6 years, the risk of a major adverse cardiovascular event was 57% higher in those with the highest levels vs. the lowest levels in the CLSA cohort after correcting for known cardiovascular risk factors (including age, sex, smoking status, lipid levels, diabetes and hypertension). 

 

Over a follow-up period of 30 years, the risk of major adverse cardiovascular events was 18% higher in those with the highest levels vs. the lowest levels in the EPIC-Norfolk cohort. 

 

Taken together with data from the middle quartiles, the results from both cohorts suggested a dose-dependent relationship: the higher the xylitol blood levels, the higher the cardiovascular event rate. 

 

Furthermore, the researchers showed that there was consistent increase in cardiovascular events with xylitol irrespective of baseline characteristics, such as age and sex. Doctor Witkowski also highlighted that the association was independent of underlying factors such as body mass index, hypertension, diabetes and lipid levels, which might predispose people to low-calorie products. 

 

“Artificial sweeteners are consumed by people who think they are healthier than sugar and they are generally regarded as safe by regulatory agencies,” noted Doctor Witkowski. “Our long-term findings in the general population highlight how little we know about the cardiovascular safety of xylitol and indicate that further studies are warranted, especially as the amount of xylitol in products continues to increase,” he concluded. 

 

Commenting on the findings, Professor Dan Atar, Member of the ESC Communication Committee, said: “Artificial sweeteners are widely embraced by modern society, and the safety ratings had been good and granted by regulatory authorities. In this observational work, however, it appears that xylitol has a negative long-term effect on cardiovascular events in the general population. As with all observational studies, causalities are difficult to infer, but this work shows that further studies are mandated into this societally important topic.” 

Hormone replacement therapy = lower Alzheimer's risk

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Estrogen-based menopausal hormone therapy = lower Alzheimer’s risk

Hormone replacement therapy (HRT) may reduce the risk of dementia, particularly for certain groups of women - according to a study from the University of East Anglia and the University of Exeter.

Hormone replacement therapy (HRT) helps treat symptoms of menopause like vaginal dryness and hot flashes.

Researchers followed more than 180,000 postmenopausal women in the UK for this, the largest study of its kind to date.

They found that women who had used HRT had a 16 per cent lower risk of developing Alzheimer’s (the main form of dementia) compared with those who had never used it.

The greatest reduction was seen in women who had undergone surgical menopause, with a 26 per cent lower risk of developing any type of dementia, compared with non‑users.

The study also found that women who naturally had lower lifetime oestrogen exposure, due to starting their periods late or early menopause, seemed to benefit more from HRT - with a 16 per cent lower risk of any type of dementia.

Prof Anne-Marie Minihane, from UEA’s Norwich Medical School and director of the Norwich Institute for Healthy Aging at UEA, led the study.

She said: “Dementia affects millions of people worldwide, with women making up almost two thirds of Alzheimer’s disease cases, the main form of dementia.

“As populations age, understanding how sex‑specific factors influence dementia risk is increasingly important.

“In addition to living longer, the reason behind the higher female prevalence is thought to be related to the effects of menopause on brain metabolism and the impact of the main genetic risk factor APOE4 being greater in women.

“We wanted to better understand how HRT could prevent dementia and to assess if particular groups of women may respond differently.”

How the research happened

Researchers analysed health data from the UK Biobank, tracking 183,450 postmenopausal women over an average follow‑up period of 13.3 years.

During that time, almost 4,000 cases of dementia were identified.

The study examined whether using HRT for at least one year was associated with the risk of developing dementia, and whether that relationship varied depending on biological and genetic factors.

The team also took into account other factors that could influence dementia risk and HRT use, such as age, socio-economic factors, other health issues and medication use.

Prof Minihane said: “We found that women who had used HRT were about 10 per cent less likely to develop dementia, and 16 percent less like to develop the Alzheimer’s disease form of dementia, than women who had never used it.

“But the protective association between HRT and dementia was not the same for all women.

Stronger benefits in specific groups

“We found that HRT is especially beneficial for women who have gone through a surgical menopause, for example after having their ovaries removed.

“In this group, those who used HRT were around 26 per cent less likely to develop dementia than women who didn’t use it.

“We also found that women whose bodies naturally produced less oestrogen over their lives - because they started their periods late or hit menopause early - seemed to get more help from HRT.

“Their risk of dementia was around 16 per cent lower with HRT.”

Genetics also played a role. The associations between HRT use and dementia were stronger in women who carry the APOE4 gene variant - a known risk factor for Alzheimer’s disease.

“This is really important because APOE4 carriers are typically considered at higher risk and have fewer established prevention options.”

Timing may matter

The age at which women started hormone therapy also appeared to influence outcomes. Those who began HRT between the ages of 46 and 56 experienced the greatest reduction in dementia risk.

This supports the so‑called “critical window” hypothesis, which suggests that hormone therapy may be more beneficial when initiated closer to the menopausal transition, rather than later in life.

The study did not find the same level of benefit when HRT was started outside this age range, reinforcing the importance of timing in hormone‑based interventions.

Implications for personalised care

“Our findings contribute to growing evidence that hormone therapy’s effects on brain health are complex and influenced by individual biological factors,” said Prof Minihane.

“While HRT has long been prescribed primarily to relieve menopausal symptoms such as hot flushes and night sweats, this work suggests it may also play a role in long‑term cognitive health for some women.”

This research builds on a previous study from UEA, which found that HRT use is associated with better memory, cognition and larger brain volumes in later life among women carrying the APOE4 ‘dementia gene’.

The team say their latest results provide a foundation for more personalised approaches to HRT prescribing - taking into account menopause type, genetic risk, lifetime hormone exposure, and age at initiation.

Prof David Llewellyn, University of Exeter Medical School, said: “These findings represent a significant step forward. Rather than asking simply whether HRT affects dementia risk, we've been able to identify which women are most likely to benefit, and when. That's the foundation on which genuinely personalised approaches to women's brain health can be built.”

This research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

Dr Amanda Collis, Executive Director for Research Strategy and Programmes at BBSRC, said: “This study provides valuable new insights into how menopause and the timing of hormone replacement therapy may influence dementia risk in women.

“The findings suggest that HRT could have greater protective benefits for some groups, highlighting the potential for more personalised approaches to prevention.”

‘Hormone replacement therapy and dementia risk among postmenopausal women: identifying responsive subgroups in the UK Biobank’ is published in the journal Alzheimer's and Dementia.

Heavy social media use tied to depression

 

Depression linked to 2.5 hours or more of daily scrolling

Peer-Reviewed Publication

University of Cincinnati

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UC Professor Hans Breiter and his research partners used a machine learning model to examine links between social media use and self-reported depression. 

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Credit: Andrew Higley

Social media use is a better predictor of depression than many other common factors such as one’s job and educational background or time spent on other activities such as playing video games, surfing the web or watching TV.

Meanwhile, researchers observed a correlation with self-reported depression in survey respondents starting at 2.5 hours of daily scrolling.

Researchers from the University of Cincinnati and Northwestern University assessed 11 years of data from the annual Media Behaviors and Influence Study starting in 2014 and found that social media use was among the most important predictors of self-reported depression.

“When it comes to depression and social media, the argument is salient across scientific test after test of those 11 years,” corresponding author and UC Professor Hans Breiter said.

“It’s a damning picture. Social media is harmful for individuals across the lifespan. We should not subject ourselves to a product using addiction science to optimize our viewing time.“

The study was published in the Nature Portfolio journal Mental Health Research.

UC researchers collaborated with co-lead author and Professor Emeritus Martin Block at Northwestern University. While numerous studies have documented associations between social media use and negative outcomes such as mental health conditions, especially depression, none have used AI to show these relationships persist in adults.

Researchers examined 183,300 anonymized surveys from adults ages 18 to 70 from the Media Behaviors and Influence Study conducted annually since 2002 by Prosper Insights & Analytics. The survey asks 1,318 questions across topics and the respondent’s health across 31 measures, including self-reported depression.

They used a machine learning model that was evaluated with tools designed to ensure its accuracy and calibration. Using this model, they found an increasing relationship between social media use and depression.

“Much of the published research has focused on younger populations, single datasets or broad measures of screen time. We need studies that distinguish social media from other digital activities and examine whether the same associations appear across different populations and years,” co-lead author and UC Research Associate Vikram Suresh said.

Researchers observed a correlation with self-reported depression among respondents who spent at least 150 minutes on social media per day. They observed the same result in each of the 11 years studied.

“Mental health and happiness are about engaging the world and having purpose, not passively watching something for hours,” Breiter said.

UC doctoral student and study co-author Johnathan Avant said people long have suspected that excessive social media use could have negative health effects.

“You can see trends on social media where they talk about the mental health toll it has on them,” Avant said.

Researchers found that social media increasingly became a bigger predictor of depression during the 11 years studied, eclipsing many other factors like TV viewing or web surfing.

UC senior research associate and co-author Nicole Vike said consumption of social media has changed over the years.

“Initially, social media was a social outlet with people you knew,” Vike said.

Now, people typically consume content made by strangers, she said.

“It’s crazy how addictive it can be. Look at chronically online content creators,” Vike said. “They often have to take a monthslong hiatus from being online for their mental health.”

The study was supported with grants from the Office of Naval Research and a donation from UC alumnus Jim Goetz.

While the $300 billion industry has become ubiquitous in daily life, UC’s senior research associate and co-author Sumra Bari said there are ways people can limit time spent on social media like setting timers, turning off notifications and fully logging out of accounts after every session to make it harder to scroll again out of habit.

But it might be unrealistic for people to simply turn it off, she said.

“There is a lot of social pressure to stay connected and be out there. So being aware of the risks as early as possible is important,” she said.

Professor emeritus Block noted, “Social media is a common marker of our cultural age much like the automobile was more than a century ago. But social media has an important negative effect through its association with depression, much like the automobile is associated with injuries from crashes and pollution.”

Breiter said their findings suggest it’s in society’s best interest to find ways to mitigate the harms of today’s deeply online culture.

“This is a wake-up call,” he said.

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Journal

npj Mental Health Research

DOI

10.1038/s44184-026-00237-y 

Consuming dairy products can increase prostate cancer risk

 

 Ahead of Prostate Cancer Awareness Month in September, a new survey finds that just 20% of men know that consuming milk and other dairy products can increase the risk of prostate cancer. After learning about the increased risk, 66% said they are likely to avoid dairy products.

The survey, conducted by Morning Consult for the Physicians Committee for Responsible Medicine among 1,102 U.S. men, also found that only 20% of men have received information from a healthcare professional regarding the link between nutrition and prostate cancer risk.

“Physicians and other healthcare professionals need more education on the dangers of dairy products and the benefits of a plant-based diet for prostate cancer,” says Noah Praamsma, MS, RDN, a dietitian and nutrition education coordinator with the Physicians Committee for Responsible Medicine.

High intakes of dairy products, including milk and cheese, increase the risk for prostate cancer, according to a meta-analysis that included 32 studies. In one study, those who had one or more servings a day of skim or low-fat milk had a 19% increased risk of prostate cancer, compared with those who rarely consumed it. In another study that followed 3,612 men for 8-10 years, men consuming the most low-fat dairy (about 3 servings per day) were more than twice as likely to develop prostate cancer than men who had the lowest dairy intake (less than 1 serving per day).

Milk and other dairy products may also increase the risk of prostate cancer mortality. In a meta-analysis of 11 studies that encompassed more than 700,000 participants and assessed dairy intake and cancer mortality rates, male participants who consumed the most whole milk increased their risk of death from prostate cancer by as much as 50%, compared with those who consumed the least amount. 

Given the prostate cancer risk associated with dairy products, 76% of men surveyed support requiring warning labels on dairy products to inform people about prostate cancer risk.

“The good news is that most men surveyed knew that consuming fruits, vegetables, grains, and beans can help protect them against prostate cancer,” adds Praamsma, “and research shows that consuming a 100% plant-based diet is the most beneficial.”

The Adventist Health Study-2 found that men who followed a vegan diet had a 35% lower prostate cancer risk than those following a nonvegetarian, lacto-ovo-vegetarian, pesco-vegetarian, or semi-vegetarian diet. A study of more than 2,000 men with prostate cancer found that those who ate the most plant-based foods had a 56% lower risk of prostate cancer progression and a 59% lower risk of prostate cancer recurrence compared with those who ate the least.

Prostate cancer is the most common cancer in men in the United States, according to the American Cancer Society’s 2024 annual report, as well as the second most common cause of cancer deaths. The American Cancer Society estimates that there will be 333,830 new cases of prostate cancer in the United States in 2026 and 36,320 deaths from prostate cancer.

Overuse of inhalers found to increase heart attack risk in asthma and COPD patients

 

Overuse of reliever inhalers is associated with higher risks of developing and dying from cardiovascular disease, including heart failure, heart attack and ischemic stroke, in asthma and COPD patients, according to a study published today in ERJ Open Research.

These ‘reliever’ inhalers can help people breathe more easily when their symptoms are particularly bad. However, it is possible to overuse them if the patient’s asthma or COPD is not being managed well by ‘preventer’ treatments.

Professor Lies Lahousse, a lead author of the study from Ghent University, Belgium and Erasmus MC Rotterdam, Netherlands, explains: “Short-acting bronchodilator overuse is common. We know that almost one out of five asthma patients and one out of three COPD patients are overusing these inhalers. In both asthma and COPD, we found that increased use of these inhalers was associated with higher risks of cardiovascular disease and death and the risk continued to rise the more inhalers patients used per year.

“Overuse of short-acting bronchodilator is usually the result of poor disease control, both COPD and uncontrolled asthma are linked to an increased risk of cardiovascular diseases and death.”

The study assessed real-world data from primary and secondary care of over 280,000 COPD and asthma patients in Belgium who used either SABA (short-acting beta-agonist), SAMA (short-acting muscarinic antagonist), both, or no short-acting bronchodilators to manage their condition. Researchers took into account differences in age, sex, socio-economic status, smoking history, nursing home residency, disease severity, and other conditions or medications.

Both SABA and SAMA bronchodilators are often used as reliever therapies by asthma and COPD patients. SABA bronchodilators increased the risk of death by 12% and 14% in asthma and COPD patients respectively compared to no use, the risk of death from SAMA bronchodilators increased by 73% and 36% respectively. The researchers also assessed how the number of inhalers used per year affected cardiovascular health. They found that using three or more inhalers per year for either bronchodilator was associated with increased risk of death compared with two or fewer inhalers per year. Patients who did not have any prior history of cardiovascular disease were found to be more vulnerable to cardiovascular problems resulting from inhaler overuse.

Professor Lahousse added: “Overuse of short-acting bronchodilators is an alarm signal which indicates uncontrolled airway inflammation and requires a medical review of treatment. It should prompt patients to have their lungs checked and healthcare providers to check adherence and inhaler technique against treatment guidelines.

“Patients should be informed that short-acting bronchodilators only relax airway muscles briefly. Uncontrolled asthma and COPD are already linked to increased risk of cardiovascular disease and death. When this is combined with overuse of SABA and SAMA bronchodilators – which both cause faster, irregular heart rates as a side effect – these risks become even more pronounced. Over-reliance on this short relief may allow the underlying disease activity progress to go unchecked. Our research should draw clinicians’ attention to the fact that overuse is common and may be associated with adverse effects, even in patients without cardiac history.”

The team is now planning to investigate whether reliever overuse can be avoided by stricter adherence to maintenance treatment, and whether cardiovascular risk assessment or specific cardiovascular therapies might decrease the risks for patients. They also hope to investigate if short-acting bronchodilator overuse in primary care will trigger healthcare providers to check the lungs and monitor disease management more closely.

Dr Pavol Pobeha from the European Respiratory Society’s expert group on monitoring airway diseases, based at the Pavol Jozef Šafárik University, Košice, Slovakia, who was not involved in the research, said: “There are no cures for asthma or COPD. As a result, the primary goal of clinicians and patients is to manage symptoms and prevent the conditions from worsening. Relief from bronchodilators plays a key role in this management, helping patients to take control of their own health and improve their quality of life, but it is important that they do not become reliant on these therapies.

“We need improved monitoring systems that give a warning signal when patients are overusing short-acting bronchodilators, enabling doctors to support their patients with the best treatment and care to manage symptoms. This will help patients and their healthcare providers to maximise the benefits of their medication whilst minimising risks.”

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Journal

ERJ Open Research

DOI

10.1183/23120541.00462-2026