Higher muscle and lower visceral fat linked to younger brain age

A recent study has discovered that a higher muscle mass with a lower visceral fat-to-muscle ratio is linked to having a younger brain age. 

“Healthier bodies with more muscle mass and less hidden belly fat are more likely to have healthier, youthful brains,” says senior study author Cyrus Raji, M.D., Ph.D., associate professor of radiology and neurology at Mallinckrodt Institute of Radiology at Washington University School of Medicine in St. Louis, Missouri, US.

“Better brain health, in turn, lowers the risk for future brain diseases, such as Alzheimer’s disease.”

The researchers suggest that interventions targeting the reduction of visceral fat while preserving muscle could improve brain aging outcomes. These could also shape future fat-loss therapies, especially ones related to GLP-1 medications.

MRI scans and AI analysis 

The team analyzed 1,164 healthy people, 52% of whom were women, using whole-body MRI scans and AI to measure muscle volume, visceral fat, and brain age. Their mean chronological age was 55.17 years, according to estimations from the scans.

The study supports that, next to MRI scans, muscle mass can also be a marker for interventions for improving brain health and improving strength.

“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,” says Raji. “In short, more muscle and a lower visceral fat-to-muscle ratio were linked to a younger brain.”

“While it is commonly known that chronological aging translates to loss of muscle mass and increased hidden belly fat, this work shows that these health measures relate to brain aging itself. It shows muscle and fat mass quantified in the body are key reflectors of brain health, as tracked with brain aging.”

Potential therapies without muscle loss

Raji underscores that the finding may point to actionable brain health goals as building muscle and reducing visceral fat is feasible for most. 

“This research has validated widely held hypotheses about the association between body composition biomarkers and brain health and provides a foundation for those biomarkers to be included in future trials of various metabolic interventions and treatments.”

He also points out that GLP-1 medications, which are increasingly being used for weight management and tackling wider health issues, may also lead to higher loss of muscle. Raji believes that the finding could point to new therapies that maintain muscles while targeting visceral fat.

“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,” he says. 

“Thus, our study can inform future treatments by promoting research that quantifies MRI of body fat, muscle, and brain age, which can help determine the optimal dosing regimens for GLP-1s to achieve the best outcomes in body and brain health.”