When the world’s largest radiology conference, RSNA 2025 (Radiological Society of North America), is held in Chicago next week, an interesting new study will be presented. Muscle mass and the amount of visceral fat, i.e. the abdominal fat around the organs, can reveal how old your brain really is.
Body composition reflects the biological age of the brain
The researchers analyzed 1,164 healthy people (average age 55 years) using whole-body MRI combined with an AI model that calculated the participants’ so-called brain age. An estimate of the brain’s biological age based on structural changes in the brain.
They found that:
- More muscle mass = younger brain
- More visceral fat in relation to muscle mass = older brain
- Subcutaneous fat (the fat on the rest of the body) shows no significant link to brain aging
It is therefore primarily the fat that lies deep in the abdomen and surrounds the organs, not the fat that lies just under the skin, that affects the brain. According to lead author Dr. Cyrus Raji, the study shows that body composition is an important indicator of the brain’s biological aging and future risk of brain diseases, such as Alzheimer’s:
“Bodies with more muscle mass and less hidden belly fat have more youthful brains,” says Raji. “And a healthier brain means a lower risk of future neurodegenerative diseases.”
Why is this important and what can you do yourself?
Visceral fat is known to drive inflammation, insulin resistance, and hormonal disruptions. All of these are factors that also affect brain aging. Muscle tissue, on the other hand, improves metabolism, blood sugar regulation, mitochondrial function, and inflammation levels. The results suggest that the body and brain age together.
The great thing is that this is controllable. You can train your muscles and reduce your belly fat by:
- Strength training
- Movement during the day
- Diet with lots of protein, fiber, healthy fats and low levels of fast carbohydrates.
- Sufficient sleep
- Stress regulation
Relevance to weight loss agents or GLP-1 drugs
The researchers also highlight that some modern weight loss drugs, such as GLP-1 agonists (e.g. Ozempic), while reducing fat, also reduce muscle mass. Future drugs should therefore target visceral fat more specifically while preserving muscle to have the best effect on brain health.
Reference
RSNA Press Release. More Muscle, Less Belly Fat Slows Brain Aging
