A new imaging study suggests that higher muscle mass and a lower ratio of visceral fat to muscle are associated with a younger biological brain age. Presented at the Radiological Society of North America’s annual meeting, the research highlights how body composition may influence brain health and future risk of diseases such as Alzheimer’s.
Researchers have identified a body profile that appears to support brain youthfulness: greater muscle mass alongside a lower amount of visceral fat relative to that muscle. Visceral fat, stored deep in the abdomen around internal organs, was associated with faster brain aging, while muscle mass was linked to a protective effect, according to findings presented at the annual meeting of the Radiological Society of North America (RSNA).(sciencedaily.com)
The study evaluated 1,164 healthy adults from four research sites, 52% of whom were women, with a mean chronological age of 55.17 years. Participants underwent whole-body MRI, including T1‑weighted sequences that helped distinguish fat, muscle and brain tissue. An artificial intelligence (AI) algorithm was used to quantify total normalized muscle volume, visceral fat (hidden belly fat), subcutaneous fat (fat under the skin) and to estimate brain age from structural brain images.(sciencedaily.com)
The data showed that a higher visceral fat‑to‑muscle ratio was associated with an older predicted brain age, whereas subcutaneous fat showed no significant association with how old the brain appeared.(sciencedaily.com) "The participants with more muscle tended to have younger-looking brains, while those with more hidden belly fat relative to their muscle had older-looking brains," said senior author Cyrus Raji, M.D., Ph.D., associate professor of radiology and neurology at Washington University School of Medicine’s Mallinckrodt Institute of Radiology in St. Louis, in an RSNA news release.(rsna.org)
"Healthier bodies with more muscle mass and less hidden belly fat are more likely to have healthier, youthful brains," Dr. Raji added. "Better brain health, in turn, lowers the risk for future brain diseases, such as Alzheimer's."(sciencedaily.com) The study underscores the close connection between physical and brain health and suggests that improving muscle mass while reducing visceral fat are realistic and potentially beneficial goals, though the research is ongoing and has not yet undergone peer review.
The findings also intersect with the growing use of glucagon-like peptide‑1 (GLP‑1) weight loss drugs such as Ozempic and similar medications, which can reduce body fat but may also contribute to muscle loss. According to the RSNA press materials, the researchers say the results could inform the design of future therapies that more selectively target visceral fat while minimizing muscle loss. "Losing fat—especially visceral fat—while preserving muscle volume would have the best benefit on brain aging and brain health based on insights from our work," Dr. Raji said.(rsna.org) In the future, whole‑body MRI and AI‑based brain‑age estimates could serve as tools to monitor how well such interventions are preserving muscle and reducing harmful visceral fat.
