A new study has discovered why exercise may prevent Alzheimer's disease, potentially paving the way for new treatments for the currently incurable condition.

Experts at Massachusetts General Hospital found that during exercise, the body releases a hormone called irisin. This hormone has been shown to reduce the brain plaques and tangles commonly associated with Alzheimer's disease onset.

While physical exercise has consistently demonstrated its ability to reduce amyloid beta deposits in mouse experiments, the exact mechanisms remained unclear until now. The study, published in the journal Neuron, clears up this mystery and also suggests potential avenues for prevention and treatment of Alzheimer's — the most common form of dementia.

The Mass General team pioneered the development of the first 3D human cell culture models for Alzheimer's. These models showcase two primary characteristics of the disease: the formation of amyloid beta deposits and subsequent tau tangles in the brain.

It's well-documented that exercise elevates the levels of the muscle-derived hormone irisin, which not only helps regulate glucose and lipid metabolism in fat tissues but also enhances energy expenditure by promoting the conversion of white fat into brown fat. Earlier research indicated that irisin is present in both human and mouse brains. However, its levels are diminished in individuals with Alzheimer's. With this knowledge, the research team introduced irisin to their 3D cell culture model of Alzheimer's.