Medical Bulletin 26/February/2026

Here are the top medical news for today:

Study Finds Even Low Plaque Levels Raise Heart Attack Risk in Women

Women may face a higher risk of heart attack even at lower levels of artery plaque compared to men, according to a new study led by researchers from Harvard Medical School. The findings, published in Circulation: Cardiovascular Imaging, suggest that current definitions of high cardiovascular risk may underestimate danger in women.

It is well known that women typically have less artery-clogging plaque than men. However, the researchers wanted to understand how differences in plaque volume affect the likelihood of major adverse cardiovascular events, such as heart attack or stroke. The study analyzed data from 4,267 outpatients with chest pain and no prior history of coronary artery disease, including 2,199 women.

Using advanced imaging, the team measured total plaque volume and plaque burden—the proportion of plaque relative to the size of the coronary artery. They found that plaque was less common in women than in men (55% versus 75%), and women had lower total plaque volume. Despite this, women experienced similar rates of major adverse cardiovascular events compared to men (2.3% versus 3.4%).

Importantly, the risk threshold differed by sex. In women, cardiovascular risk became elevated at a total plaque burden of 20%, compared to 28% in men. Moreover, risk increased more sharply in women at lower plaque levels, whereas in men it rose more gradually and required greater plaque accumulation.

Researchers suggest that because women generally have smaller coronary arteries, even modest plaque buildup may have a greater impact. The findings highlight the need for sex-specific interpretation of coronary imaging and more tailored strategies to assess and manage heart disease risk in women.

REFERENCE: Brendel, Jan M., Mayrhofer, Thomas, et al.; Risk in Women Emerges at Lower Coronary Plaque Burden Than in Men: PROMISE Trial; Circulation: Cardiovascular Imaging; doi: 10.1161/CIRCIMAGING.125.019011; https://doi.org/10.1161/CIRCIMAGING.125.019011

Daily Peanut Butter Intake Linked to Improved Muscle Strength in Older Adults: Study

A clinical trial conducted by researchers at Deakin University found that eating a daily serving of peanut butter significantly improved muscle power in older adults. The study, carried out by the university’s Institute for Physical Activity and Nutrition (IPAN), was recently published in the Journal of Cachexia, Sarcopenia and Muscle.

The six-month trial, known as the Capacity of Older Individuals after Nut Supplementation (COINS) study, was led by Dr. Sze-Yen Tan. It involved 120 community-dwelling adults aged 66 to 89 who were at risk of falls. Participants were randomly divided into two groups. One group consumed 43 grams (about three tablespoons) of natural peanut butter daily, while the control group continued their usual diet and lifestyle.

At the end of the study, participants completed repeated sit-to-stand tests, a common measure of lower-body muscle power. Those who consumed peanut butter performed the tests faster than those in the control group, indicating stronger muscle power. Importantly, although the peanut butter group increased their intake of protein and healthy unsaturated fats—consuming about 10 grams of protein daily from the supplement—they did not gain weight.

Muscle power is critical for daily activities such as climbing stairs and getting up from a chair, and it plays a major role in preventing falls, a leading cause of reduced independence and poorer quality of life in older adults.

Researchers suggest that peanut butter could serve as an affordable, accessible alternative to commercial oral nutrition supplements, which can be costly and less appealing in taste. Because it is familiar, easy to consume, and suitable for those with dental issues, peanut butter may offer a practical strategy to support strength training and improve overall nutrition in seniors.

REFERENCE: Feyesa, I., et al. (2026). Effects of Peanut Butter Supplementation on Older Adults’ Physical Function: A 6-Month Randomised Controlled Trial. Journal of Cachexia, Sarcopenia and Muscle. DOI: 10.1002/jcsm.70221. https://onlinelibrary.wiley.com/doi/10.1002/jcsm.70221

Intense Exercise May Alter Gut Bacteria Composition, Study Finds

New research from Edith Cowan University suggests that training intensity may influence the gut microbiome, potentially affecting both health and athletic performance. The study, led by PhD candidate Bronwen Charlesson, explored how different training loads—from high-intensity periods to lighter recovery phases—shape gut bacteria in athletes.

Previous research has shown that athletes tend to have a distinct gut microbiota compared to the general population. They often display greater microbial diversity, higher concentrations of short-chain fatty acids, and differences in the abundance of certain bacterial species. While diet is known to play a role, fitness indicators such as oxygen uptake have also been linked to microbiome variations.

In this study, changes in training load were associated with measurable shifts in gut health markers. During periods of intense training, athletes showed differences in short-chain fatty acid levels and bacterial composition. One possible explanation involves lactate, which rises in the bloodstream during strenuous exercise. Lactate can travel to the gut, where certain bacteria break it down, potentially encouraging the growth of specific microbial strains and altering the overall balance.

The research also found that diet quality declined during low training periods. Although total carbohydrate and fiber intake remained similar, athletes consumed more processed foods, fewer fruits and vegetables, and slightly more alcohol during rest phases. At the same time, gut transit time slowed significantly, which may have further influenced microbial composition.

While scientists are still uncovering how the gut microbiome directly impacts performance, early evidence suggests it may help regulate lactate processing and pH balance—both important for recovery and endurance. Researchers say more studies are needed, but understanding the interaction between training intensity, diet, and gut health could help athletes optimize performance at a microscopic level.

REFERENCE: B. Charlesson, J. Jones, C. Abbiss, P. Peeling, S. Watts, C.T. Christophersen. Training load influences gut microbiome of highly trained rowing athletes. Journal of the International Society of Sports Nutrition, 2025; 22 (1) DOI: 10.1080/15502783.2025.2507952