Exercise-Induced Hormone May Protect Against Alzheimer's and Dementia

A study published in Nature Medicine suggests a hormone called irisin released during exercise has a strong connection with the prevention of neurodegeneration in Alzheimer's and other dementias, reports New Atlas . The researchers found the presence of irisin is significantly reduced in the hippocampus and central nervous system of people with late-stage Alzheimer's as well as in animals engineered with the disease. The artificial impairment of irisin levels in the brains of normal mice caused reductions in synaptic plasticity and memory, while raising those levels in mice engineered with Alzheimer's significantly improved those same functions. Furthermore, the inhibition of irisin in the brain of Alzheimer's-modeled mice impeded the beneficial effects of exercise. Daily exercise among the Alzheimer's-engineered mice that lacked the irisin-block decelerated synaptic degeneration, or even shielded them against it. The implication is that exercise can at least retard, even possibly prevent, the onset of neurodegeneration through a muscle-to-brain axis mediated by the hormone.