Muscles send protective signals to the Parkinson brain
Why does exercise help people with Parkinson’s disease? It turns out muscles don’t just generate movement. They also send protective chemical signals directly to the brain.
In Parkinson’s disease, the brain cells that produce dopamine progressively die off. Exercise demonstrably slows that decline, but the reasons have long remained unclear. The researchers explain in a narrative review that muscle tissue, during physical activity, secretes proteins called myokines, which travel through the bloodstream and exert protective effects on surviving nerve cells in the brain.
Among the best-studied of these proteins are BDNF (a growth factor for nerve cells), IGF-1 (involved in cell repair), and irisin (which influences cellular energy metabolism). Together they promote the formation of new connections between nerve cells, suppress inflammation in brain tissue, and support mitochondrial function, a process often impaired in Parkinson’s disease.
Muscle loss makes Parkinson’s worse
The review also highlights a less-discussed problem: people with Parkinson’s lose muscle mass (sarcopenia) relatively quickly. That muscle weakness increases fall risk, limits mobility, and accelerates overall functional decline. Losing muscle also means producing fewer myokines, which in turn reduces brain protection. This creates a downward cycle that operates independently of the direct neurological damage.
Resistance training and balance-focused exercise show the strongest evidence for improving motor symptoms in clinical trials. Aerobic exercise benefits mood and cognition. A combination of both appears to address the widest range of Parkinson’s-related impairments.
Could a drug mimic exercise?
The scientific interest extends beyond physical activity itself. Researchers want to know whether specific myokines could be used as medicines for people who are physically unable to exercise. This concept, sometimes called an exercise mimetic, remains hypothetical. The underlying mechanisms are not yet fully mapped, and the effects of individual myokines on the human brain are complex.
Even so, this review makes clear that muscles are more than engines of movement. They are an active part of the brain’s defense system, which makes preserving muscle mass in aging more relevant than ever.
Want to research this yourself? Try these search terms in Google Scholar or PubMed:
- myokines neuroprotection Parkinson’s disease
- sarcopenia dopaminergic neurons
- exerkines muscle-brain crosstalk