Study: Exercise Can Protect Against Alzheimer's Disease | Health

According to a new study, exercise produces a hormone that can improve memory and protect against Alzheimer's disease. Researchers have previously discovered a hormone called irisin, which is released into the circulation during a physical activity. Early studies have suggested that irisine plays primarily a role in energy metabolism.

The latest study published in the journal Nature Medicine revealed that the hormone could also promote neuronal growth in the hippocampus of the brain, an area essential for learning and memory.

"This could help explain why physical activity improves memory and seems to play a protective role in brain disorders such as Alzheimer's disease," said Ottavio Arancio, a professor at Columbia University in the USA.

Arancio and his colleagues at the Federal University of Rio de Janeiro in Brazil and Queens University of Canada first looked for a link between irisin and Alzheimer's disease in humans. Using tissue samples taken from brain stores, they discovered that irisin was present in the human hippocampus and that hormone levels in the The hippocampus was reduced in people with Alzheimer's disease.

To explore what irisin does in the brain, the team has turned to the mouse. These experiments show that irisin, in mice, protects brain synapses and animal memory: when irisine is deactivated in the hippocampus of healthy mice, synapses and memory are weakened. Likewise, increasing levels of irisin in the brain has improved both measures of brain health, researchers said.

PHARMACEUTICAL COMPOUNDS FOR INCREASING BRAIN LEVELS

The researchers then examined the effect of exercise on irisin and the brain. They found that mice that swam almost daily for five weeks did not develop memory impairment despite beta-amyloid infusions – the protein that clogs neurons and destroys the memory involved in Alzheimer's.

The researchers found that blocking irisine with a drug completely eliminated the benefits of swimming. Mice that swam and were treated with irisin-blocking substances did not behave better in memory tests than sedentary animals after beta-amyloid infusions.

The findings suggest that irisin could be exploited to find a new treatment for the prevention or treatment of dementia in humans, said Arancio. The team is currently researching pharmaceutical compounds that can increase brain levels of the hormone or mimic its action.