Athletes have long acknowledged that working out makes them feel good due to the release of endorphins that boost mood. Now there is evidence coming out of animal studies at Columbia University that exercise produces another hormone, irisin, that may improve memory and protect against Alzheimer’s disease.
Irisin is present in the brain’s hippocampus, the region critical for learning and memory. In people with Alzheimer’s, irisin levels are lower. Irisin protects the brain’s synapses which in turn preserves memory. Synapses are the junction between nerve cells where nerve impulses cross. If the synapse does not work, nerve messages are not transmitted. In the mice experiments, if irisin was disabled, synapses and memory were weakened. In mice who swam almost every day, they did not develop memory problems even when they got infusions of beta-amyloid – the neuron-clogging, memory-robbing protein associated with Alzheimer’s. Exercise helped to protect the mice because irisin was released. This research suggests that encouraging exercise not only promotes overall health but protects brain function, too.
