Probiotics can restore gut microbiome in breastfed infants

In recent years, scientists have learned that key beneficial infant gut bacteria Bifidobacterium infantis are disappearing from infants in high-resource areas such as the United States and Europe. Now, a new study published in the journal mSphere found that supplementing exclusively breastfed infants with a probiotic, B. infantis EVC001, between 2 and 4 months of age can successfully restore beneficial bacteria in their gut.

“The REMEDI study shows that it’s not too late to restore a healthy gut microbiome in breastfed infants. B. infantis can successfully take hold even after the newborn period,” said corresponding study author Jennifer Smilowitz, Ph.D., assistant professor of Cooperative Extension in the Department of Nutrition, University of California, Davis.

A healthy early-life gut microbiome is linked to gut health, immune education and development, and overall infant health. Unlike many probiotics, B. infantis is uniquely adapted to thrive on human milk oligosaccharides, the natural sugars found in breast milk, allowing it to persist rather than simply pass through the gut. 

The researchers conducted the REMEDI study to test whether the benefits they had previously observed in a study on newborns fed B. infantis alongside human milk could be replicated in older, exclusively breastfed infants with more established gut microbiomes that could potentially be resistant to changes. 

The researchers tested how different doses of the B. infantis probiotic (high, medium and low, as well as a placebo) impacted the gut bacteria of exclusively breastfed infants. The infants provided stool samples before, during and after taking the supplement, and the researchers analyzed these to see how their microbiomes responded. The researchers tested whether lower doses of B. infantis, which are commercially available, produced similar effects as the newborn study which used a high dose of the B. infantis probiotic.  

The researchers found that B. infantis could successfully increase beneficial gut bacteria in older, exclusively breastfed infants, even after the newborn period. All doses tested worked, and the beneficial bacteria remained present even after supplementation stopped. 

“These findings suggest that B. infantis supplementation can restore the infant gut even past the newborn stage,” Smilowitz said. “Unlike many probiotics that disappear once supplementation stops, B. infantis was able to take hold and remain in the gut when paired with human milk, which naturally contains the human milk oligosaccharides it needs to grow. This means even short-term supplementation at a range of doses may have lasting benefits for breastfed infants. The finding that all tested doses were effective suggests this approach may be adaptable to real-world settings where access, timing or dose can vary.”
 

 

High-fat diets make liver cells more likely to become cancerous

 One of the biggest risk factors for developing liver cancer is a high-fat diet. A new study from MIT reveals how a fatty diet rewires liver cells and makes them more prone to becoming cancerous.

The researchers found that in response to a high-fat diet, mature hepatocytes in the liver revert to an immature, stem-cell-like state. This helps them to survive the stressful conditions created by the high-fat diet, but in the long term, it makes them more likely to become cancerous.

“If cells are forced to deal with a stressor, such as a high-fat diet, over and over again, they will do things that will help them survive, but at the risk of increased susceptibility to tumorigenesis,” says Alex K. Shalek, director of the Institute for Medical Engineering and Sciences (IMES), the J. W. Kieckhefer Professor in IMES and the Department of Chemistry, and a member of the Koch Institute for Integrative Cancer Research at MIT, the Ragon Institute of MGH, MIT, and Harvard, and the Broad Institute of MIT and Harvard.

The researchers also identified several transcription factors that appear to control this reversion, which they believe could make good targets for drugs to help prevent tumor development in high-risk patients.

Shalek; Ömer Yilmaz, an MIT associate professor of biology and a member of the Koch Institute; and Wolfram Goessling, co-director of the Harvard-MIT Program in Health Sciences and Technology, are the senior authors of the study, which appears today in Cell. MIT graduate student Constantine Tzouanas, former MIT postdoc Jessica Shay, and Massachusetts General Brigham postdoc Marc Sherman are the co-first authors of the paper.

Cell reversion

A high-fat diet can lead to inflammation and buildup of fat in the liver, a condition known as steatotic liver disease. This disease, which can also be caused by a wide variety of long-term metabolic stresses such as high alcohol consumption, may lead to liver cirrhosis, liver failure, and eventually cancer. 

In the new study, the researchers wanted to figure out just what happens in cells of the liver when exposed to a high-fat diet — in particular, which genes get turned on or off as the liver responds to this long-term stress.

To do that, the researchers fed mice a high-fat diet and performed single-cell RNA-sequencing of their liver cells at key timepoints as liver disease progressed. This allowed them to monitor gene expression changes that occurred as the mice advanced through liver inflammation, to tissue scarring and eventually cancer.

In the early stages of this progression, the researchers found that the high-fat diet prompted hepatocytes, the most abundant cell type in the liver, to turn on genes that help them survive the stressful environment. These include genes that make them more resistant to apoptosis and more likely to proliferate.

At the same time, those cells began to turn off some of the genes that are critical for normal hepatocyte function, including metabolic enzymes and secreted proteins.

“This really looks like a trade-off, prioritizing what’s good for the individual cell to stay alive in a stressful environment, at the expense of what the collective tissue should be doing,” Tzouanas says.

Some of these changes happened right away, while others, including a decline in metabolic enzyme production, shifted more gradually over a longer period. Nearly all of the mice on a high-fat diet ended up developing liver cancer by the end of the study.

When cells are in a more immature state, it appears that they are more likely to become cancerous if a mutation occurs later on, the researchers say.

“These cells have already turned on the same genes that they’re going to need to become cancerous. They’ve already shifted away from the mature identity that would otherwise drag down their ability to proliferate,” Tzouanas says. “Once a cell picks up the wrong mutation, then it’s really off to the races and they’ve already gotten a head start on some of those hallmarks of cancer.”

The researchers also identified several genes that appear to orchestrate the changes that revert hepatocytes to an immature state. While this study was going on, a drug targeting one of these genes (thyroid hormone receptor) was approved to treat a severe form of steatotic liver disease called MASH fibrosis. And, a drug activating an enzyme that they identified (HMGCS2) is now in clinical trials to treat steatotic liver disease.

Another possible target that the new study revealed is a transcription factor called SOX4, which is normally only active during fetal development and in a small number of adult tissues (but not the liver).

Cancer progression

After the researchers identified these changes in mice, they sought to discover if something similar might be happening in human patients with liver disease. To do that, they analyzed data from liver tissue samples removed from patients at different stages of the disease. They also looked at tissue from people who had liver disease but had not yet developed cancer.

Those studies revealed a similar pattern to what the researchers had seen in mice: The expression of genes needed for normal liver function decreased over time, while genes associated with immature states went up. Additionally, the researchers found that they could accurately predict patients’ survival outcomes based on an analysis of their gene expression patterns.

“Patients who had higher expression of these pro-cell-survival genes that are turned on with high-fat diet survived for less time after tumors developed,” Tzouanas says. “And if a patient has lower expression of genes that support the functions that the liver normally performs, they also survive for less time.”

While the mice in this study developed cancer within a year or so, the researchers estimate that in humans, the process likely extends over a longer span, possibly around 20 years. That will vary between individuals depending on their diet and other risk factors such as alcohol consumption or viral infections, which can also promote liver cells’ reversion to an immature state.

The researchers now plan to investigate whether any of the changes that occur in response to a high-fat diet can be reversed by going back to a normal diet, or by taking weight-loss drugs such as GLP-1 agonists. They also hope to study whether any of the transcription factors they identified could make good targets for drugs that could help prevent diseased liver tissue from becoming cancerous.

“We now have all these new molecular targets and a better understanding of what is underlying the biology, which could give us new angles to improve outcomes for patients,” Shalek says.

 

Cannabis products with more THC slightly reduce pain but cause more side effects

A new systematic evidence review finds that cannabis products that carry relatively high levels of the psychoactive compound tetrahydrocannabinol, commonly known as THC, may provide short-term improvements in pain and function. 

However, the review found THC-based products led to an increased risk of common adverse symptoms like dizziness, sedation and nausea.  

At the same time, the review found that recent randomized controlled trials involving products mainly or only containing cannabidiol, or CBD, which does not have psychoactive properties, demonstrated almost no improvement in managing pain. 

“This may be surprising to people,” said lead author Roger Chou, M.D., senior adviser for the Pacific Northwest Evidence-based Practice Center at Oregon Health & Science University. “Conventional wisdom was that CBD was promising because it doesn’t have euphoric effects like THC and it was thought to have medicinal properties. But, at least in our analysis, it didn’t have an effect on pain.” 

The cannabis plant contains both THC and CBD. Both are believed to act on the body’s endocannabinoid system, which modulates pain. Many U.S. states, including Oregon, have legalized cannabis for both recreational and medicinal use, and many people have turned to cannabis to treat conditions including pain, anxiety and sleep. 

The review, an update to a living review first published in 2022, was conducted by researchers at OHSU and published today in the Annals of Internal Medicine. 

Researchers incorporated several additional short-term placebo-controlled randomized trials since the previous review. Both the original review and the new update found some evidence of pain relief for two prescribed products, dronabinol and nabilone, which are made of 100% THC or its analogue. Dronabinol and nabilone are FDA approved for treatment of nausea and vomiting due to chemotherapy, and one of them, dronabinol, is approved for HIV wasting syndrome. 

The new review found that oral THC-only products slightly reduce pain severity.  

Chou noted that the improvement in pain was relatively small — on the order of a half point to a point compared with a placebo on a 10-point pain scale. 

“It’s complicated because cannabis products are complicated,” he said. “It’s not like taking a standardized dose of ibuprofen, for example. Cannabis is derived from a plant and has multiple chemicals in addition to THC and CBD that may have additional properties depending on where it’s grown, how it’s cultivated and ultimately prepared for sale.”  

The medical profession is equally divided on the benefits of medicinal use of cannabis: The American College of Physicians recently declined to recommend inhaled cannabis for non-cancer pain whereas a previous expert panel issued a soft recommendation for people with chronic cancer or non-cancer pain when standard treatments did not work. 

Chou said the review’s finding that CBD products failed to reduce pain will surprise many people. 

“CBD-based products are widely available in dispensaries. Many people use these products and they think it helps,” he said. “Our goal is to provide some scientific basis to help people make their decisions.” 

The researchers categorized cannabinoids by the ratio of THC to CBD (whether it was high, comparable or low); whether the product was synthetic (produced in a lab) or plant-based (as well as the degree of purification); and the administration method.  

The data showed that oral THC-only products slightly reduced pain severity, but that across trials they were also linked to moderate-to-large increases in dizziness, sedation and nausea. 

They concluded that more research is needed on long-term outcomes and other types of cannabis products; whether there are differences between THC-only products in effectiveness; and to better understand how results based on the products evaluated in the review apply to products that are available in dispensaries. 

In addition to Chou, co-authors included Rongwei Fu, Ph.D., Azrah Y. Ahmed, B.A., and Benjamin J. Morasco, Ph.D. 

The project was funded by the Agency for Healthcare Research and Quality of the U.S. Department of Health and Human Services, contract number 75Q80120D00006. Statements in the report should not be construed as endorsement by the AHRQ or the Department of Health and Human Services. 

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Journal

Annals of Internal Medicine

DOI

10.7326/ANNALS-25-03152  

Menopause hormone therapy does not appear to impact dementia risk

 

A major review of prior research has found no evidence that menopause hormone therapy either increases or decreases dementia risk in post-menopausal women, in a new study led by University College London (UCL) researchers.

The findings, commissioned by the World Health Organisation (WHO) and published in The Lancet Healthy Longevity, add much-needed clarity to a hotly-debated topic, and reinforce current clinical guidance that menopause hormone therapy, also called hormone replacement therapy or HRT, should be guided by perceived benefits and risks and not for dementia prevention.

The new systematic review and meta-analysis is the most comprehensive and rigorous synthesis of evidence on menopause hormone therapy and dementia risk completed to date, including data from over one million participants.

The study publication follows a November announcement by the U.S. Food and Drug Administration (FDA) that it would remove the ‘black box’ warnings on menopause hormone therapy products. These warnings had previously included disproven claims about potential long-term health risks, including a claim of potential increased dementia risk. The FDA announcement further suggested that menopause hormone therapy might reduce the risk of Alzheimer’s disease, however, the findings of this latest review indicate that this claim is also not supported by the available evidence.

Lead author, PhD student Melissa Melville (UCL Psychology & Language Sciences), said: “Across the globe, dementia disproportionately affects women, even after accounting for women’s longer lifespans, so there’s a pressing need to understand what might be driving that risk, and to identify ways to reduce women’s risk of dementia.

“Menopause hormone therapy is widely used to manage menopausal symptoms, yet its impact on memory, cognition and dementia risk remains one of the most debated issues in women's health. Conflicting research and concerns about potential harms have fuelled public and clinical debate, leaving women and clinicians unsure whether menopause hormone therapy might raise or reduce their risk of dementia.”

The international research team, based in the UK, Ireland, Switzerland, Australia and China, pulled together the best evidence on any potential links between menopause hormone therapy and dementia risk (including Alzheimer’s disease and other types of dementia), which included one randomised controlled trial and nine observational studies, with a total of 1,016,055 participants.

They found no significant association between menopause hormone therapy and the risk of dementia or mild cognitive impairment. Additional analyses of subgroups within the study participant pools, based on timing, duration and type of menopause hormone therapy, still did not reveal any significant effects. They found no evidence that menopause hormone therapy affected dementia risk after early menopause.

The researchers caution that their findings are limited by the scarcity of relevant randomised controlled trials, and that a lot of the evidence is of relatively low certainty. They say there remains a need for high-quality, long-term research, particularly in women from ethnic minority backgrounds or with early menopause, premature ovarian insufficiency, or mild cognitive impairment.

Senior author Professor Aimee Spector (UCL Psychology & Language Sciences) said: “Currently, the World Health Organisation provides no guidance on menopause hormone therapy and cognitive outcomes, leaving a critical gap for clinicians and policymakers. To cut through the noise, we reviewed the most rigorous research there is on the subject and found that menopause hormone therapy does not appear to impact dementia risk either positively or negatively.”

“This review will help to inform the upcoming WHO guidelines on reducing the risk of cognitive decline and dementia, which are expected to be released in 2026.

“More high-quality, long-term research is still needed to fully understand the long-term impacts of menopausal hormone therapy.”

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Journal

The Lancet Healthy Longevity

DOI

10.1016/j.lanhl.2025.100803 

Long-term physical activity protects against metabolic syndrome

– but increasing activity later in life is beneficial too

 A new Finnish study shows that adults who remain physically active throughout adulthood have a markedly lower prevalence of metabolic syndrome at the age of 61 than those whose leisure-time physical activity remains low. However, physical activity in early late adulthood, especially muscle strengthening exercises, may mitigate the risks associated with earlier inactivity.

The study is part of the ongoing Jyväskylä Longitudinal Study of Personality and Social Development, conducted at the University of Jyväskylä, Finland, which has followed the same participants for more than 50 years. In this analysis, researchers examined the leisure-time physical activity of 159 participants at ages 27, 42, 50 and 61, as well as their cardiometabolic health, particularly the prevalence of metabolic syndrome, at age 61. Metabolic syndrome refers to the clustering of several cardiovascular risk factors, such as increased waist circumference, elevated blood pressure, impaired glucose metabolism, and unhealthy blood lipid levels.

The researchers identified three trajectories of leisure-time physical activity across the 34-year follow-up: consistently active, increasingly active, and consistently inactive. Those who were consistently active exercised several times a week from early adulthood onwards, while those who increased their activity reached a similar level in midlife. Consistently inactive individuals exercised at most once a week throughout adulthood.

Compared to the consistently active group, consistently inactive participants had nearly a fourfold risk of metabolic syndrome at the beginning of late adulthood, while those who increased their activity had roughly a twofold risk. These differences diminished after taking into account participants’ current  engagement in different types of physical activity at age 61.

“Long-term physical activity is clearly linked to better metabolic health in late adulthood, but our findings show that being active later in life also supports health. Muscle-strengthening physical activities in particular appear to play an important role in metabolic health,” says Postdoctoral Researcher Tiina Savikangas.

Of the individual components of metabolic syndrome, long-term leisure-time activity was associated with lower waist circumference and more favourable blood lipid values compared with those who had been less active during adulthood. These differences also decreased once current physical activity was considered. Participants who regularly engaged in muscle-strengthening exercise and active commuting had higher levels of beneficial HDL cholesterol; in addition, those who did muscle-strengthening exercise had, on average, a smaller waist circumference than those who did not. 

Eero Haapala, University Lecturer at the University of Jyväskylä and Adjunct Professor in the Institute of Biomedicine at the University of Eastern Finland emphasises that the findings reinforce broader evidence on the importance of physical activity throughout life:

“The health benefits of physical activity are not limited to a single life stage. It is important to encourage individuals to stay active, but equally important to communicate that it is never too late to start.”

The publication draws on data from the Jyväskylä Longitudinal Study of Personality and Social Development (JYLS) and particularly its latest data collection phase Developmental Psychological Perspectives on Transitions at Age 60: Individuals Navigating Across the Lifespan (TRAILS). The JYLS study began at the Department of Psychology and was conducted there for many years before continuing at the Faculty of Sport and Health Sciences and the Gerontology Research Center, University of Jyväskylä, Finland. A total of 206 women and men took part in the TRAILS data collection in 2020–2021, and this analysis included a subsample of 159 participants who attended a health examination. Leisure-time physical activity frequency was assessed with questionnaires at ages 27, 42, 50, and 61. Regular participation in vigorous, muscle-strengthening, commuting, and occupational physical activity were assessed through questionnaires at age 61. Components of metabolic syndrome – waist circumference, HDL cholesterol, triglycerides, fasting glucose, and systolic and diastolic blood pressure – were measured during the health examination and from fasting blood samples. Participants’ medication was also taken into account. Individuals who exceeded the clinical cut-off for at least three components were classified as having metabolic syndrome. The longitudinal study has been funded by the Research Council of Finland. Preparation of this publication was additionally supported by the Juho Vainio Foundation.

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DOI

10.1249/MSS.000000000000388

Swearing boosts performance by helping people feel focused, disinhibited,

Letting out a swear word in a moment of frustration can feel good. Now, research suggests that it can be good for you, too: Swearing can boost people’s physical performance by helping them overcome their inhibitions and push themselves harder on tests of strength and endurance, according to research published by the American Psychological Association.

“In many situations, people hold themselves back – consciously or unconsciously – from using their full strength,” said study author Richard Stephens, PhD, of Keele University in the U.K.  “Swearing is an easily available way to help yourself feel focused, confident and less distracted, and ‘go for it’ a little more.” 

The article was published in the journal American Psychologist.

Previous research by Stephens and others has found when people swear, they perform better on many physical challenges, including how long they can keep their hand in ice water and how long they can support their body weight during a chair push-up exercise.

“That is now a well replicated, reliable finding,” Stephens said. “But the question is -- how is swearing helping us? What's the psychological mechanism?”

He and his colleagues believed that it might be that swearing puts people in a disinhibited state of mind. “By swearing, we throw off social constraint and allow ourselves to push harder in different situations,” he said. 

To test this, the researchers conducted two experiments with 192 total participants. In each, they asked participants to repeat either a swear word of their choice, or a neutral word, every two seconds while doing a chair pushup. After completing the chair pushup challenge, participants answered questions about their mental state during the task. The questions included measures of different mental states linked to disinhibition, including how much positive emotion participants felt, how funny they found the situation, how distracted they felt and how self-confident they felt. The questions also included a measure of psychological “flow,” a state in which people become immersed in an activity in a pleasant, focused way.

Overall, and confirming earlier research, the researchers found that participants who swore during the chair pushup task were able to support their body weight significantly longer than those who repeated a neutral word. Combining the results of the two experiments as well as a previous experiment conducted as part of an earlier study, they also found that this difference could be explained by increases in participants’ reports of psychological flow, distraction and self-confidence – all important aspects of a disinhibition.

 “These findings help explain why swearing is so commonplace,” said Stephens. “Swearing is literally a calorie neutral, drug free, low cost, readily available tool at our disposal for when we need a boost in performance.”

In the future, the researchers plan to explore whether this boost from swearing works in any context where success depends on overcoming hesitancy, according to study co-author Nicholas Washmuth, DPT, of the University of Alabama in Huntsville. “Our labs are now studying how swearing influences public speaking and romantic approach behaviors, two situations where people tend to hesitate or second-guess themselves," he said. 

Article: “Don’t Hold Back: Swearing Improves Strength Through State Disinhibition,” by Richard Stephens, PhD, Harry Dowber, MSc, and Christopher Richardson, MSc, Keele University; and Nicholas Washmuth, DPT, University of Alabama in Huntsville. American Psychologist, published online Dec. 18, 2025. 

Most parents need more clarity on early peanut introduction guidelines

Feeding babies peanut-containing foods as early as possible can help prevent peanut allergy, but a new study published in JAMA Network Open found that parents need more support to get it right. Interviews with parents revealed widespread confusion about the purpose, risks, and timing of early peanut introduction guidelines.

“While some parents we talked to understood correctly that starting their baby on peanut foods trains the immune system in order to prevent the development of peanut allergy, other parents mistakenly believed that the purpose is to test if their baby is allergic – a misconception that fueled fears of severe allergic reaction, leading to hesitation and delays in peanut introduction,” said lead author Waheeda Samady, MD, a hospital-based pediatrician at Ann & Robert H. Lurie Children’s Hospital of Chicago and Associate Professor of Pediatrics at Northwestern University Feinberg School of Medicine.

“For prevention of peanut allergy, timing and consistency are of the essence,” she said. “We encourage peanut introduction as soon as the baby starts eating solids, before or around 6 months of age. It’s also important to continue peanut exposure twice a week through the first year and into toddler years. Feeding babies peanut foods just once or twice is not enough.”

Early peanut introduction guidelines were issued in 2017 following groundbreaking research showing over 80% reduction in peanut allergy development. Peanut allergy affects approximately 2% of U.S. children and is the least likely food allergy to be outgrown, making prevention through early introduction an important public health strategy.

Dr. Samady and colleagues analyzed 49 interviews with Chicago parents of infants aged 8-13 months from diverse backgrounds. Participants were recruited from primary care academic clinics, federally qualified health centers and private clinics.

Researchers also found that parents mostly did not understand that eczema places their baby at high risk for developing food allergy, making early peanut introduction even more critical.

“If a baby has eczema, peanut introduction should start early, around 4 months of age, if possible, to maximize peanut allergy prevention coupled with good skincare,” said Dr. Samady. “Pediatricians need to reinforce this message, given that most parents we interviewed were not aware that eczema increases the baby’s chances of developing food allergies.”

In the study, parents reported that pediatricians were their primary source of information about early peanut introduction.

“Pediatricians are key to successful guideline implementation, but they need better resources for families to provide comprehensive information during busy well-child visits," Dr. Samady noted. "Overall, we found that parents are accepting of early peanut introduction, but they need clearer guidance and more support.”

Dr. Samady emphasized that improved messaging and resources for families should clarify that early peanut introduction prevents peanut allergy through regular dietary exposure, address the connection between eczema and food allergy risk, provide specific guidance on timing and frequency, and reassure parents about the low risk of severe allergic reactions in infants.

“Parents need to be reassured that if their baby is allergic to peanut, they may see hives, some swelling, or vomiting, but allergic reactions in infancy are usually mild,” she explained. “We should empower parents with information and action plans so this does not stop them from participating in early peanut introduction.”

Eating more high-fat cheese and cream = lower risk of developing dementia

  Highlights:

• High-fat cheeses have more than 20% fat and include cheddar, Brie and Gouda.
• People who ate 50 grams or more of high-fat cheese daily had a 13% lower risk of dementia than those eating less than 15 grams daily.
• People who consumed 20 grams or more of high-fat cream daily had a 16% lower risk of dementia than those who consumed none.
• No association was found for low-fat dairy products, fermented milk, milk or butter.
• More research is needed to explore whether consuming certain high-fat dairy offers some level of protection for the brain.

Eating more high-fat cheese and high-fat cream may be linked to a lower risk of developing dementia, according to a new study published on December 17, 2025, in Neurology®, the medical journal of the American Academy of Neurology. This study does not prove that eating high-fat cheese and high-fat cream lowers the risk of dementia, it only shows an association.

High-fat cheeses contain more than 20% fat and include varieties such as cheddar, Brie and Gouda. High-fat creams typically contain 30-40% fat and include whipping cream, double cream and clotted cream. These are commonly labeled as “full-fat” or “regular” versions in stores.

“For decades, the debate over high-fat versus low-fat diets has shaped health advice, sometimes even categorizing cheese as an unhealthy food to limit,” said Emily Sonestedt, PhD, of Lund University, Sweden “Our study found that some high-fat dairy products may actually lower the risk of dementia, challenging some long-held assumptions about fat and brain health.”

Researchers analyzed data from 27,670 people in Sweden with an average age of 58 at the start of the study. They were followed for an average of 25 years. During the study, 3,208 people developed dementia.

Participants kept track of what they ate for a week and answered questions about how often they ate certain foods during the past few years. They also talked with researchers about how they prepared their food.

Researchers compared people who ate 50 grams or more of high-fat cheese daily to people who ate less than 15 grams daily. For example, 50 grams of cheese is about two slices of cheddar or half a cup of shredded cheese and is approximately 1.8 ounces. A typical serving of cheese is one ounce. Of those who ate more high-fat cheese, 10% developed dementia by the end of the study. Of those who ate less, 13% developed dementia.

After adjusting for age, sex, education and overall diet quality, researchers found that people who ate more high-fat cheese had a 13% lower risk of developing dementia compared to those who ate less. When looking at specific types of dementia, they found people who ate more high-fat cheese had a 29% lower risk of vascular dementia.

Researchers also found a lower risk of Alzheimer’s disease among those who ate more high-fat cheese, but only among those not carrying the APOE e4 gene variant—a genetic risk factor for Alzheimer’s disease.

Researchers also compared people who consumed 20 grams or more of high-fat cream daily to people who consumed none. For example, 20 grams of high-fat cream is about 1.4 tablespoons of heavy whipping cream. A recommended serving is about 1-2 tablespoons.

After similar adjustments, researchers found that those who consumed high-fat cream daily had a 16% lower risk of dementia compared to those who consumed none.

No associations were found between dementia risk and eating low-fat cheese, low-fat cream, high- or low-fat milk, butter or fermented milk, which includes yogurt, kefir and buttermilk.

“These findings suggest that when it comes to brain health not all dairy is equal,” said Sonestedt. “While eating more high-fat cheese and cream was linked to a reduced risk of dementia, other dairy products and low-fat alternatives did not show the same effect. More research is needed to confirm our study results and further explore whether consuming certain high-fat dairy truly offers some level of protection for the brain.”

A limitation was that study participants were all from Sweden, so results may not be the same for other populations. Sonestedt noted that in Sweden, cheese is often eaten uncooked, while in the United States, cheese is often heated or eaten with meat. Therefore, she says it is important that studies also be conducted in the United States. 

Nicotine in all forms is toxic to the heart and blood vessels

Nicotine is toxic to the heart and blood vessels, regardless of whether it is consumed via a vape, a pouch, a shisha or a cigarette, according to an expert consensus report published in the European Heart Journal [1] today (Thursday). The report brings together the results of the entire literature in the field and is the first to consider the harms of all nicotine products, rather than smoking only.

The report highlights a dramatic rise in the use of vapes, heated tobacco and nicotine pouches, particularly among adolescents and young adults, with evidence that three-quarters of young adult vapers have never smoked before.

The authors of the report are calling for urgent action to curb the growing number of adolescents and young people becoming addicted to nicotine, particularly a ban on flavours and social media and influencer advertising, and effective taxation and regulation across all nicotine products.

The paper comes at a critical regulatory turning point, following the European Commission’s revised Tobacco Taxation Directive, which for the first time introduces a minimum tax on e-liquids, heated tobacco and nicotine pouches.

Key findings of the expert consensus report:

·         Nicotine is a potent cardiovascular toxin, causing damage to the heart and blood vessels, regardless of the delivery system.

·         No nicotine-containing product is safe for blood vessels or the heart. This includes e-cigarettes, heated tobacco, waterpipes, cigars and oral nicotine pouches.

·         Youth addiction is rising rapidly, fuelled by flavours, social media marketing and regulatory loopholes.

·         Passive exposure to smoke, vape and heated tobacco emissions also causes vascular harm.

·         Vapes and pouches are not effective cessation tools, but rather are an entry point to smoking and often lead to dual use (alongside cigarettes).

·         Nicotine-related illness cost hundreds of billions of Euros in healthcare and productivity losses every year.

·         Policy gaps persist across Europe, enabling new nicotine products to avoid taxation, packaging rules and public-use restrictions.

However, the researchers caution that the longer-term effects of newer tobacco products are not yet known, so more research is needed to fully understand their impacts. They also acknowledge that many people use cigarettes alongside other nicotine products, making it harder to pinpoint the effects of the individual nicotine products.

The report’s authors call for:

• Flavour bans for all nicotine products
• Taxation on all nicotine products that is proportional to nicotine content
• Plain packaging for all nicotine products
• Comprehensive indoor and outdoor smoke- and aerosol-free laws
• Strict online sales controls and social media advertising bans
• Integration of nicotine prevention into cardiovascular care
• National cardiovascular prevention plans that explicitly address nicotine

Professor Münzel said: “Nicotine is not a harmless stimulant; it is a direct cardiovascular toxin. Across cigarettes, vapes, heated tobacco, and nicotine pouches, we consistently see increased blood pressure, damage to blood vessels and a higher risk of heart disease. No product that delivers nicotine is safe for the heart.

”Our findings show that nicotine by itself, even without the multitude of toxic combustion products, tar, or free radicals present in cigarette smoke, drives cardiovascular damage.

“The narrative of ‘safer nicotine’ must end. Europe urgently needs unified regulation that covers all nicotine products, especially to protect adolescents, who are now the primary targets of aggressive marketing. Otherwise, we risk losing an entire generation to nicotine addiction.

“The next heart attack, the next stroke, the next cardiovascular death may not come from a cigarette, but from a flavoured pod, a nicotine pouch, or a waterpipe in a café. If Europe fails to act now, we will face the largest nicotine addiction wave since the 1950s.”

Professor Crea added: “Our knowledge of cardiovascular risk keeps evolving. Obviously, we must abate the well-known traditional risk factors including hypertension, diabetes, obesity and smoking. Traditional risk factors are only responsible for around half of cardiovascular disease. The remaining half is explained by emerging risk factors including pollution, depression and infections.

“Use of nicotine, in any form, also contributes to this cardiovascular risk. Cardiovascular disease remains the number one killer, so a strong, comprehensive call to action is needed.”

Professor Lüscher said: “This paper is a wake-up call for regulators. The shift from cigarettes to e-cigarettes and flavoured pouches is no effective harm reduction; it is rather a transformation of addiction strategies.”

“We need political action. Flavour bans, effective taxation, comprehensive advertising restrictions, and the inclusion of vaping and heated tobacco in all smoke-free laws are no longer optional – these are essential measures to prevent cardiovascular disease.”

“Science is clear: the cardiovascular toxicity of nicotine is evidence-based by now. The duty now lies with legislators to protect the public, especially children, from a new epidemic of addiction and disease.”

 

Medical + psychological complexities of steroid cream withdrawal

 There is little awareness, particularly among clinicians, of the medical and psychological complexities of ‘topical steroid withdrawal’—the body’s adverse response to the prolonged use of these powerful creams to treat inflammatory skin conditions when they are either tapered or suddenly stopped—warn doctors in the journal BMJ Case Reports.

 

The condition, also known as ‘TSW syndrome,’ ‘steroid addiction,’ and ‘red burning skin syndrome,’ is poorly recognised, diagnosed, managed, and researched, say the report authors, one of whom speaks from direct experience.

 

This has prompted unfounded fears, particularly on social media, that all steroids are harmful and should be avoided in favour of other often untested, unproven remedies, they caution.

 

Steroid creams are widely used for the treatment of various inflammatory skin conditions, such as eczema and psoriasis, for which they are very effective, note the report authors.

They are available in 4 different strengths, ranging from mild to very strong.

 

But withdrawing treatment—particularly the stronger formulations—after protracted use can prompt a rebound flare-up of symptoms, which can be even more severe and debilitating than the original condition, they point out.

 

These symptoms can spread well beyond the original areas of treatment and additionally trigger insomnia and depression.

 

The underlying causes are only partially understood, while diagnosis can be tricky because of the highly variable presenting symptoms, they add.

 

In a bid to promote wider recognition of the syndrome, the report authors present a case exemplifying some of the challenges involved for both clinicians and patients.

 

The case involved a middle-aged woman with a history of atopic eczema since infancy that  had been treated with varying strengths of steroid creams for sometimes lengthy periods.

 

She was referred to dermatology for review and explained that she had had a flare-up of symptoms which had persisted for 18 months until she was treated with a gradually tapering 4-week course of steroid tablets.

 

She had significant skin thinning, particularly on her arms, and thickened leathery skin (lichenification) in the folds of her elbows and wrists.

 

She was prescribed further steroid creams to ward off future flare-ups, which she decided to stop using a month after her review. Her skin symptoms then significantly worsened as did her general health.

 

She had widespread skin reddening and experienced a burning sensation and intense itching. Her skin became dry, scaly, thickened and cracked, exposing deep tears in parts.

 

She also reported swelling in the thighs, feet, ankles, and around the eyes and extensive skin folds and sagging. Systemic symptoms included dizziness, nausea, hair loss, insomnia, low blood pressure, extremes of temperature and sensations of dampness and numbness. She experienced intense nerve pain and sharp jolts of pain akin to an electric shock. Her symptoms were incapacitating.

 

She suspected topical steroid withdrawal. It took 28 months for her symptoms to resolve, during which time she decided against any further treatment, even skin moisturisers. She has since experienced occasional mild flare-ups but has not applied steroid creams.

 

Commenting on her experience, she explains that at times the severity and extent of her symptoms left her unable to get out of bed, and feeling like she might die.

 

She writes: “I should have liked to have been supported to withdraw safely. Without a diagnosis, this was not possible: I was being treated for eczema, which included continued steroid treatment. It is my understanding that TSW patients will not recover while steroids are part of their recovery plan.”

 

She continues: “I am pleased that more is now known about TSW, but I should like to see TSW diagnoses routinely being considered where steroids are no longer controlling a patient’s skin or when a patient simply feels that something is ‘different’ to usual. More than that, I should like to see TSW prevention a priority, so that there is no new generation of patients who have to endure the suffering that I have endured.”

 

The report authors acknowledge: “Despite the increasing recognition of TSW within the dermatological community, it remains underdiagnosed in routine practice. Patients often turn to online forums and self-treatment due to diagnostic challenges, which can lead to inconsistent or even harmful practices.”

 

They continue: “While social media has raised awareness for poorly recognised conditions like TSW, it has significantly contributed to steroid phobia. From our medical experience, exposure to alarming online narratives has led many patients to refuse [topical steroid] management of their conditions, both dermatological and otherwise, despite reassurance by clinicians about their safe and approved use.”

 

They conclude: “Breaking the cycle of distrust and enhancing patient care requires clinicians to address patients' concerns with empathy, prioritising patient education. By fostering open discussions about patients’ beliefs and perspectives while simultaneously providing evidence-based recommendations, clinicians can support well-informed decision making and improve treatment outcomes.

Gum disease may be linked to plaque buildup in arteries, higher risk of major CVD events

 There is increasing evidence that gum disease is associated with increased risk of cardiovascular events, including heart attack, stroke, atrial fibrillation, heart failure and cardiometabolic health conditions. Effective prevention and treatment of gum disease, also called periodontal disease, could potentially decrease the burden of cardiovascular disease, according to a new scientific statement published today in the American Heart Association’s flagship journal Circulation.

The new American Heart Association scientific statement, “Periodontal Disease and Atherosclerotic Cardiovascular Disease,” features new data supporting an association between periodontal disease and atherosclerotic cardiovascular disease (ASCVD) and updates the Association’s 2012 scientific statement. ACSVD, the leading cause of death globally, is caused by buildup of arterial plaque (fatty deposits in the arteries) and refers to conditions that include coronary heart disease, stroke, peripheral artery disease and aortic aneurysms.

“Your mouth and your heart are connected,” said Chair of the scientific statement writing group Andrew H. Tran, M.D., M.P.H., M.S., FAHA, a pediatric cardiologist and the director of the preventive cardiology program at Nationwide Children's Hospital in Columbus, Ohio. “Gum disease and poor oral hygiene can allow bacteria to enter the bloodstream, causing inflammation that may damage blood vessels and increase the risk of heart disease. Brushing, flossing and regular dental checkups aren’t just about a healthy smile—they’re an important part of protecting your heart.”

Highlights of the statement include:

• Periodontal disease is a chronic inflammatory condition affecting over 40% of U.S. adults over age 30. The earliest stage is gingivitis (inflammation of the gums due to buildup of oral plaque). If left untreated, gingivitis may progress to periodontitis, where the gums begin to pull away from the teeth, forming small pockets that can trap bacteria and lead to infection. The most advanced stage, severe periodontitis, involves extensive damage to the bones supporting the teeth; teeth may become loose and fall out. This stage often requires surgical intervention. 

• Periodontal disease is more common in individuals with poor oral hygiene and other cardiovascular disease risk factors, such as high blood pressure, overweight or obesity, diabetes and smoking. The prevalence of periodontal disease is also higher among men, older adults, individuals with low physical activity and people affected by adverse social determinants of health, such as lower socioeconomic status, food insecurity and/or lack of access to health care including dental care.

• Although periodontal disease and ASCVD share common risk factors, emerging data indicates there is an independent association between the two conditions. Potential biological mechanisms linking periodontal disease with poor cardiovascular outcomes include direct pathways such as bacteria in the blood and vascular infections, as well as indirect pathways such as chronic systemic inflammation.

• Numerous studies have found that periodontal disease is associated with an increased risk of heart attack, stroke, atrial fibrillation, heart failure, peripheral artery disease, chronic kidney disease and cardiac death. Although periodontal disease clearly contributes to chronic inflammation that is associated with ASCVD, a cause-and-effect relationship has not been confirmed.

• There is also no direct evidence that periodontal treatment will help prevent cardiovascular disease. However, treatments that reduce the lifetime exposure to inflammation appear to be beneficial to reducing the risk of developing ASCVD. The treatment and control of periodontal disease and associated inflammation may contribute to the prevention and improved management of ASCVD.

• People with one or more cardiovascular disease risk factors are considered to be at higher risk and may benefit from regular dental screenings and targeted periodontal care to address chronic inflammation. Previous studies have found that more frequent tooth brushing is associated with lower 10-year ASCVD risk (13.7% for once-daily or less brushing vs. 7.35% for brushing three or more times per day) and reduced inflammatory markers.

• More research, including long-term studies and randomized controlled trials, is needed to determine whether periodontal treatment can impact ASCVD progression and outcomes.

• In addition, the role of socioeconomic status, access to dental care and other social factors that adversely affect health should be explored to develop targeted prevention and treatment strategies that can help reduce the prevalence and adverse outcomes of periodontal disease and ASCVD.

Healthy Nordic diet good for type 2 diabete, fatty liver disease

 A healthy Nordic diet, high in dietary fibre from whole grains, fruits and vegetables but with a small percentage of saturated fat, can assist in the treatment of both type 2 diabetes and non-alcoholic fatty liver disease. This has been shown in a new clinical study in which the researchers compared three different types of diet.  

After one year, researchers at Uppsala University have been able to show in this new study that a ‘healthy Nordic diet’ is better than both the Nordic Nutrition Recommendations and a low-carbohydrate diet when it comes to treating non-alcoholic fatty liver disease and type 2 diabetes.

“The healthy Nordic diet gave the best results in the study participants with diabetes; just over 20% of their liver fat was reduced and blood sugar (glucose) control improved over one year. More than half of the participants also saw a remission of their fatty liver disease. This makes these results equally important for people with non-alcoholic fatty liver disease as those with type 2 diabetes,” says Ulf Risérus, Professor of Clinical Nutrition and Metabolism, who led the study. 

Evaluated the effect of three different diets

The study was a randomised controlled trial in which 150 people with type 2 diabetes, or prediabetes, were randomly assigned to follow one of three diets for one year:

1) An anti-lipogenic diet, meaning a low-carbohydrate diet also low in animal-derived foods and high in polyunsaturated fats from the plant kingdom. Emphasis was placed on high-fat foods such as sunflower oil, walnuts, pumpkin and sunflower seeds, low-carbohydrate vegetables and protein-rich beans, lentils and some lean dairy products. 

2) A healthy Nordic diet, which can be seen as a Nordic variant of the Mediterranean diet. It was low in saturated fat, but high in dietary fibre from whole grains, fruits and vegetables, with an emphasis on foods such as oat and rye flakes, oat bran, rye bread, crispbread, rapeseed oil, almonds, apples, pears, blueberries, raspberries, cabbage and peas, along with mackerel and salmon, low-fat natural yoghurt and cultured milk products, and plant-based cooking fat.

3) Control group, meaning usual care based on dietary advice according to the current Nordic Nutrition Recommendations, which is a diet rich in different types of fruits, vegetables, legumes, olive oil, and lean dairy products.

In all three groups, participants were to limit their consumption of red and processed meats, sweetened drinks, sweets and candy, and snacks with added sugar.

The benefits of the Nordic diet surprised the researchers

All three diets were expected to have beneficial effects, but the researchers wanted to investigate which was the most effective in reducing both liver fat and blood glucose levels. That the Nordic diet turned out to be so good surprised the researchers, who had assumed that the anti-lipogenic diet would yield the best results. 

“The study shows that both the anti-lipogenic diet and the Nordic diet were relatively similar in reducing liver fat as well as ‘bad’ LDL cholesterol. But the healthy Nordic diet was more effective in reducing blood glucose over the long term, and also had more beneficial effects on body weight, inflammation and lipid profile, as well as reducing signs of liver damage,” Ulf Risérus explains.

The study also shows that the diets were surprisingly easy to follow.

“Even though the participants were allowed to eat as much as they wanted from the foods recommended, they still lost weight. In many previous studies of different diets, calorie intake has been restricted, which is effective in the short term, but increases hunger and can be difficult to follow in the longer term,” says Michael Fridén, the lead author of the study.

Can be used to treat diabetes

Although some of the beneficial effects of the healthy Nordic diet could be explained by the participants’ weight loss, the researchers found that weight loss only explained just over half (56 per cent) of the effect on liver fat.

“This is very interesting, as it suggests that the diet itself has contributed to reducing fat deposits in the liver, but probably also to improved blood glucose levels and lipid values as well as reducing inflammation. There has been a great need to find new, evidence-based diets for long-term diabetes care. Our results are important for future dietary recommendations and are particularly important for overweight people with Type 2 diabetes or prediabetes,” says Ulf Risérus.