Medical Bulletin 09/August/2025 - Video

Here are the top medical news for the day:

Eating French Fries May Be Associated with 20% Increased Risk of T2DM: Study

A new study led by the Harvard T.H. Chan School of Public Health and published in the BMJ has found that consuming French fries three times a week is associated with a 20% increased risk of developing type 2 diabetes (T2D). In contrast, other forms of potatoes—such as baked, boiled, or mashed—did not show a significant link to diabetes risk. The study also found that replacing any type of potato with whole grains may reduce the risk of T2D.

The study, described as the most comprehensive of its kind on the relationship between potatoes and diabetes, followed the diets of 205,107 adults over several decades. It analyzed participants from the Nurses’ Health Study, Nurses’ Health Study II, and the Health Professionals Follow-up Study. Over 30 years, these individuals regularly completed dietary questionnaires and reported health conditions, including T2D diagnoses. During the study period, 22,299 participants developed type 2 diabetes.

The findings revealed that while French fries significantly raised T2D risk, baked, boiled, and mashed potatoes did not. Replacing any form of potatoes with whole grains like brown rice, whole grain pasta, or farro was linked to reduced diabetes risk. Notably, swapping French fries with whole grains cut the risk by 19%.

The researchers also used a meta-analytic approach based on 24 prior cohort studies to validate their findings, involving over 500,000 participants and 43,000 T2D cases globally.

“The public health message here is simple and powerful: Small changes in our daily diet can have an important impact on risk of type 2 diabetes. Limiting potatoes—especially limiting French fries—and choosing healthy, whole grain sources of carbohydrate could help lower the risk of type 2 diabetes across the population,” said corresponding author Walter Willett, professor of epidemiology and nutrition.

Reference: Mousavi S M, Gu X, Imamura F, AlEssa H B, Devinsky O, Sun Q et al. Total and specific potato intake and risk of type 2 diabetes: results from three US cohort studies and a substitution meta-analysis of prospective cohorts BMJ 2025; 390 :e082121 doi:10.1136/bmj-2024-082121

Vitamin D in Pregnancy Linked to Child’s Cognitive Development: Study Finds

A new study published by the Environmental influences on Child Health Outcomes (ECHO) Cohort suggests that higher levels of vitamin D during pregnancy may lead to better cognitive performance in children aged 7 to 12. The findings, published in the American Journal of clinical nutrition, add to the growing body of research on prenatal nutrition, indicate that vitamin D may play a critical role in brain development—particularly early in pregnancy and especially among children born to Black mothers.

The researchers tracked vitamin D levels in pregnant women and later assessed their children’s cognitive performance, focusing on problem-solving and information processing. The children were evaluated using cognitive tests that measure executive functioning and working memory, but not language-based skills like vocabulary. The study found that while vocabulary scores did not appear linked to prenatal vitamin D levels, higher levels during early pregnancy correlated with better cognitive scores in other areas.

Importantly, the study highlighted a stronger association in children of Black mothers. This group is known to be at higher risk for vitamin D deficiency due to higher levels of melanin in the skin, which reduces the body’s ability to synthesize vitamin D from sunlight. Researchers say this makes early intervention and supplementation even more crucial.

“Our study provides important new evidence that early pregnancy may be a critical period when vitamin D has the greatest potential to support cognitive development,” said Melissa M. Melough, PhD, RD of the University of Delaware. “This highlights a key opportunity for clinicians to enhance screening and support for vitamin D supplementation before and during pregnancy.”

Vitamin D deficiency is relatively common during pregnancy and has previously been associated with early brain development.

While the findings underscore the importance of vitamin D in pregnancy, researchers stress the need for further studies to determine the ideal dosage and timing of supplementation.

Reference: Melough, M. M., McGrath, M., Palmore, M., Collett, B. R., Kerver, J. M., Hockett, C. W., ... & Thompson, A. (2025). Gestational vitamin D concentration and child cognitive development: a longitudinal cohort study in the Environmental influences on Child Health Outcomes Program. The American journal of clinical nutrition, 122(2), 571-581.

More Steps, Faster Pace May Be Linked to Lower Heart Risk in Hypertensive Adults

A new study published in the European Journal of Preventive Cardiology has found that walking more steps each day—even below the popular 10,000-step target—and doing so at a brisk pace is associated with a significantly lower risk of serious heart and vascular conditions in people with high blood pressure. The research analyzed data from more than 36,000 individuals and revealed a strong link between increased physical activity and reduced cardiovascular risk.

High blood pressure affects over 1.28 billion people globally and is a major contributor to heart disease, stroke, and heart failure. Despite known benefits of physical activity, the precise amount required to reduce heart-related risks in hypertensive individuals has remained unclear—until now.

Researchers used accelerometer data from 32,192 participants in the UK Biobank study. These individuals wore wrist devices for seven consecutive days between 2013 and 2015 to measure their step count and walking speed. They were followed for nearly eight years, during which 1,935 cardiovascular events occurred.

The researchers found that for every additional 1,000 steps walked per day—starting from a baseline of 2,300 steps—there was a 17% reduction in the overall risk of major adverse cardiovascular events (MACE). Specifically, this step increase was linked to a 22% lower risk of heart failure, a 9% reduction in heart attack risk, and a 24% decrease in stroke risk. In absolute terms, this equated to 31.5 fewer MACE events, 7.2 fewer heart failure events, 9.9 fewer heart attacks, and 10.4 fewer strokes per 10,000 person-years.

Professor Emmanuel Stamatakis, Director of the Mackenzie Wearables Research Hub at the University of Sydney, Australia, who supervised the study, said: “Our findings offer patients accessible and measurable targets for heart health, even below 10,000 steps daily. Clinicians should promote physical activity as standard care, especially in patients with high blood pressure. Our results can inform new, tailored public health recommendations for these patients. Future recommendations on walking in people with high blood pressure could consider promoting higher stepping intensity.”

While the study's strengths include its large sample size and objective physical activity measurements, researchers acknowledged some limitations, including potential changes in activity over time and the observational nature of the study. Nonetheless, the evidence strongly supports the role of increased, brisk walking in reducing cardiovascular risks for people with high blood pressure.

Reference:https://escardio.sharepoint.com/sites/Press/Shared%20Documents/Forms/AllItems.aspxid=%2Fsites%2FPress%2FShared%20Documents%2F2025%2FJournal%20press%20releases%2FEJPC%20Step%20Count%2007%2E08%2Fzwaf441%5FAU%2Epdf&parent=%2Fsites%2FPress%2FShared%20Documents%2F2025%2FJournal%20press%20releases%2FEJPC%20Step%20Count%2007%2E08&p=true&ga=1