Study Links Body Fat and Muscle Mass to Brain Aging

A recent study has established a significant connection between body fat, muscle mass, and the perceived age of the brain. Conducted by researchers at the Washington University School of Medicine in St. Louis, Missouri, the findings were shared at the annual meeting of the Radiological Society of North America this month and highlighted in a Washington Post article. The research underscores the role of physical health in brain aging, particularly the impact of visceral fat and muscle mass.

The study analyzed whole-body scans from over 1,000 healthy participants aged between their 40s and early 60s. Utilizing artificial intelligence, researchers measured each individual’s total muscle mass and body fat. To evaluate the apparent age of the participants’ brains, they compared these scans to a database of tens of thousands of other brain images. The results indicated that participants’ brain scans either corresponded to their chronological age or were aligned with those of younger or older individuals.

According to Cyrus Raji, the study’s senior author and an associate professor of radiology and neurology at Washington University, “The larger the muscle bulk, the younger-looking the brain. And the more visceral fat that was present, the older-looking the brain.” This observation points to the potential importance of maintaining muscle mass and reducing visceral fat to support cognitive health as individuals age.

The implications of this study are significant, especially given the rising prevalence of Alzheimer’s disease. The Alzheimer’s Association reports that more than seven million Americans aged 65 and older currently live with Alzheimer’s, a number projected to nearly double to almost 13 million by 2050.

While the benefits of exercise on brain health are widely recognized, the study suggests a deeper understanding of how body composition specifically affects cognitive function. Exercise has been previously linked to a lower risk of developing Alzheimer’s or other forms of dementia. For instance, a clinical trial published in July 2023, known as the U.S. POINTER trial, demonstrated that a comprehensive approach combining physical and cognitive exercises, along with proper nutrition and health monitoring, can enhance brain function in older adults.

The exercise regimen in the U.S. POINTER trial involved 30 to 35 minutes of moderate to intense aerobic activity four times a week, complemented by strength and flexibility workouts twice weekly. This multifaceted approach highlights that exercise is not the only means to bolster brain health but serves as a crucial component in a broader strategy.

As researchers continue to explore the relationship between body composition and cognitive aging, the findings of this study emphasize the need for a proactive approach to maintaining physical health. While the study has yet to undergo peer review or formal publication, its preliminary results contribute valuable insights into the factors that influence brain aging and cognitive decline.