Medical Bulletin 11/March/2026

Here are the top medical news for today:

Regular Multivitamin Use Associated With Slower Aging in Older Adults: Study

A new study suggests that taking a daily multivitamin may help slow biological aging in older adults. Researchers from Mass General Brigham analyzed data from a large clinical trial and found that regular multivitamin use over two years was associated with a modest but measurable reduction in the pace of aging. The findings were published in Nature Medicine.

Biological age refers to how quickly the body’s cells and tissues age, which may differ from a person’s chronological age. To evaluate this process, scientists often use epigenetic clocks, which track changes in DNA methylation—small chemical modifications that influence how genes are expressed. These changes accumulate over time and can help estimate a person’s biological aging rate.

The research used data from the COcoa Supplement Multivitamin Outcomes Study (COSMOS), a large randomized clinical trial involving older adults. For this analysis, researchers examined DNA methylation data from blood samples of 958 healthy participants, whose average age was about 70 years. Participants were randomly assigned to receive either a daily multivitamin, cocoa extract, both, or a placebo.

Scientists assessed five different epigenetic clocks at the beginning of the study and again after one and two years. Compared with the placebo group, participants taking a daily multivitamin showed slower biological aging across all five clocks. Two of these clocks are known to strongly predict mortality risk. Overall, the effect was equivalent to approximately four months less biological aging over the two years.

The benefits were particularly noticeable among individuals who had a higher biological age than their chronological age at the start of the study. Researchers say further studies are needed to determine whether this slowing of biological aging leads to measurable health benefits, such as improved cognition or reduced risk of conditions like cancer and cataracts.

REFERENCE: Li, S., et al. (2026). Effects of daily multivitamin–multimineral and cocoa extract supplementation on epigenetic aging clocks in the COSMOS randomized clinical trial. Nature Medicine. DOI: 10.1038/s41591-026-04239-3. https://www.nature.com/articles/s41591-026-04239-3

Sleep and Diet Identified as Key Drivers of Immunome Variation: Study

A new population-based study has highlighted how everyday lifestyle factors and environmental exposures shape the human immune system. Researchers analyzed data from 1,001 participants in the Human Phenome Atlas (THPA) cohort to explore how external exposures influence variations in the immunome, which refers to the collection of immune cells and their functions. The findings suggest that lifestyle and environmental factors account for a measurable portion of immune system differences between individuals.

The researchers found that exposures explained 10.74% of the variation in immune system characteristics. Through systematic analysis, they identified 55 immunophenotypes—distinct immune cell traits—linked to 20 individual exposures and three combined exposure patterns. Among these factors, sleep and diet emerged as the most influential lifestyle exposures affecting immune function.

Sleep patterns were found to influence the proportions of innate immune cells, while diet affected the expression of key immune cell surface proteins. The study also revealed that different sleep behaviors may affect immune responses in distinct ways. For example, short-term late sleep onset was associated with increased secretion of IL-1β, an inflammatory molecule, whereas long-term late sleep patterns were linked to chronic inflammation accompanied by broader metabolic changes.

Further analysis showed that the biological pathways connecting lifestyle factors and immune responses differ depending on the exposure. The effects of sleep on immunity were primarily mediated through changes in the transcriptome, which reflects gene activity. In contrast, dietary influences were mainly associated with the metabolome, the collection of small molecules involved in metabolism.

Using these insights, researchers developed transcriptomic and metabolomic indexes that combine molecular signals linked to immune responses. These indexes may help reflect overall immune health and identify risks for chronic diseases, potentially offering new tools for future health monitoring and personalized disease prevention strategies.

REFERENCE: Zhao, Y., et al. (2025). The Influence of Sleep and Diet on Human Peripheral Immunity and Chronic Health Conditions. Research. DOI: 10.34133/research.1081. https://spj.science.org/doi/10.34133/research.1081

Study Finds Women at Higher Risk of Cardiometabolic-Linked Liver Fibrosis Than Men

A new study suggests that women with certain cardiometabolic risk factors may face a sharper increase in the risk of Liver Fibrosis than men with the same conditions. The research, published in JAMA Network Open, highlights important sex differences in how metabolic health influences liver disease risk.

Liver fibrosis occurs when repeated inflammation causes scar tissue to build up in the liver. Over time, this scarring can progress to serious complications such as Cirrhosis, liver failure, and Liver Cancer. Although men generally have higher overall rates of fibrosis, severe cases are increasingly being observed in women, prompting researchers to investigate possible underlying factors.

The study was conducted by scientists from the Keck School of Medicine of USC using data from nearly 6,000 U.S. adults collected between 2017 and 2020 through the National Health and Nutrition Examination Survey (NHANES). The dataset included detailed information such as blood tests, clinical measurements, lifestyle factors, and ultrasound imaging used to detect liver fibrosis and fat accumulation in the liver.

Researchers examined several cardiometabolic risk factors, including Type 2 Diabetes, high waist circumference, high blood pressure, abnormal cholesterol levels, and the presence of multiple metabolic risk factors. While women initially had lower baseline rates of liver fibrosis than men, their risk increased more sharply when these factors were present.

For example, high waist circumference increased fibrosis rates about 11-fold in women, compared with a fourfold increase in men. Similarly, diabetes or prediabetes was associated with a 2.8-fold increase in fibrosis risk in women, compared with a 1.4-fold increase in men. Women with two or more metabolic risk factors had an 8.4-fold higher risk of fibrosis.

Researchers believe hormonal factors, including changes in Estrogen during menopause, may partly explain these differences. The findings emphasize that managing cardiometabolic health is crucial not only for preventing heart disease but also for protecting liver health.

REFERENCE: Albhaisi, S., et al. (2026). Sex-Specific Cardiometabolic Profiles and Severity of Liver Fibrosis. JAMA Network Open. DOI: 10.1001/jamanetworkopen.2026.0863. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2846021