A new study suggests that having more muscle mass and less visceral fat may help keep the brain younger as people age. The findings, to be presented at the annual meeting of the Radiological Society of North America (RSNA), highlight how body composition—not just age—may influence long-term brain health.
Visceral fat, often called “hidden fat” or deep belly fat, surrounds vital organs such as the liver, heart, and kidneys. As people get older, visceral fat tends to increase while muscle mass declines — a combination that researchers say could accelerate brain aging.
🧩 Muscle vs. Visceral Fat: A Clear Link to Brain Age
“We know someone’s biological age doesn’t always match their chronological age — the same applies to the brain,” said study author Dr. Cyrus Raji of Washington University School of Medicine.
According to researchers, people with higher muscle mass and a lower visceral fat-to-muscle ratio showed younger brain ages, while those with more visceral fat and less muscle appeared to have older-looking brains.
The study analyzed 1,164 healthy adults, average age 55, using full-body MRI scans to measure fat, muscle, and brain structure. An AI algorithm — trained on over 5,500 brain scans — calculated each participant’s “brain age.”
Visceral Fat, Inflammation, and Dementia Risk
The relationship held true only for visceral fat, not subcutaneous fat (the type found just under the skin).
Visceral fat is strongly linked to:
- insulin resistance
- diabetes
- high cholesterol
- chronic inflammation
Raji explained that long-term systemic inflammation is one of the mechanisms that may raise the risk of Alzheimer’s disease and other forms of dementia.
Why BMI Doesn’t Tell the Full Story
Experts say the findings reinforce the limitations of using BMI to measure health. BMI cannot distinguish between muscle, visceral fat, or fat distribution.
“You could have a normal BMI but high visceral fat and still have an older brain,” Raji noted.
Doctors instead recommend:
- Waist circumference (over 35 inches for women, 40 for men is high risk)
- Waist-to-hip ratio (above 0.85 for women, 0.9 for men increases risk)
Accurately measuring visceral fat usually requires MRI scans, which can cost thousands of dollars.
Strength Training Can Help Protect the Brain
The good news: increasing muscle mass and reducing visceral fat doesn’t require expensive scans.
“Anyone can exercise — at any age,” said Dr. Siddhartha Angadi of the University of Virginia. Resistance and aerobic training both help lower visceral fat.
Guidelines recommend:
- 2 days a week of strength training
- 150 minutes a week of moderate aerobic activity
- 8–12 reps per exercise, 1–3 sets
- Body-weight exercises for beginners
“There’s nothing that reverses brain aging,” Angadi said. “But you can slow it dramatically.”
Exercise Benefits Start Immediately
Even small amounts of movement offer big returns.
“The biggest health benefit comes in the first few minutes of exercise,” said Prof. Glenn Gaesser of Arizona State University.
This includes:
- brisk walking
- stair climbing
- at-home resistance exercises
Research suggests that muscle releases chemicals that influence brain health — one reason consistent exercise reduces the risk of cognitive decline and Alzheimer’s.
Muscle Health Matters at Every Age
With more people taking GLP-1 medications like Ozempic for weight loss, scientists warn about maintaining muscle mass.
“If you’re losing weight rapidly, you’re losing muscle too,” said Dr. David D’Alessio of Duke University. “Strength training becomes essential.”
Even without weight loss, experts say muscle preservation is critical for longevity, mobility, and cognitive health.
“If you want a healthy brain, you need healthy muscle,” Gaesser said.
