The hormone generated by muscle tissue is carried around the body in the bloodstream. Researchers from the Federal University of Rio de Janerio found those with AD have lower levels of irisin compared to healthy patients. The team was able to induce learning and memory deficits in mouse studies by removing the hormone, and were able to reverse these effects by restoring the hormone; when irisin signalling was blocked in animal AD models the brain benefits of exercise were lost.
Better brain health with age is linked to physical activity, the team suggests these findings highlight a biological mechanism may contribute to the beneficial effects. People that are not able to exercise regularly with dementia or are at high risk of dementia may benefit from drugs to target irisin.
According to James Pickett of the Alzheimer’s Society these findings add to mounting evidence of the relationship between lifestyle factors such as physical activity and dementia.
