Loss of muscle mass can be a hidden sign of dementia

In people with sarcopenia, the risk of dementia was found to be 42 % higher. At the same time, the researchers emphasize that it’s not just about weight. What’s more important is how body composition changes with age: how much muscle there is, and how strong and functional it is. According to the lead author of the study, weight alone is not enough to assess the risk of dementia; the condition of the muscles plays an equally important role.

The link between obesity and dementia depends on age. If in people under 65 years of age (in middle age) obesity increases the risk of dementia by 9%, then for those over 65 the picture changes: in this group, obesity, on the contrary, was associated with a 17% lower risk. This is not a reason to gain weight in old age: we are talking about a complex, non‑linear relationship between body composition, aging, and brain health. Rather, these data show that risk mechanisms work differently at different stages of life.

Separately, the scientists examined what is known as sarcopenic obesity — a condition in which a person simultaneously has an excess of fat and a decrease in muscle mass and function. However, there is still little data on this topic: only four studies met the analysis criteria, and no clear statistical link with the risk of dementia could be found. According to Professor Mario Ciervo, this indicates the need for long‑term studies: we currently do not understand enough about how exactly muscle loss and fat accumulation interact over time and affect the brain.

In middle age, it is especially important to avoid unhealthy weight gain, and as one ages, to maintain muscle strength and function. Regular physical activity and a balanced diet play a key role here. As Professor Warren Harding from Alzheimer’s WA notes, these results once again highlight the value of simple measures: exercise, maintaining mobility and stability (to reduce the risk of falls), as well as other healthy lifestyle factors — from nutrition to brain training.

Thus, muscle health can provide protection for cognitive functions. Monitoring muscle mass and regularly engaging the muscles is one of the accessible ways to support brain health and reduce the risks associated with aging.