Exercising may slow down the rate of memory loss in people with Alzheimer's disease, a new study suggests.

Alzheimer's disease is the most common form of dementia - it currently affects around 35,000 people in Ireland. Symptoms can include memory loss, disorientation, mood swings and problems with language.

There is no cure for the disease and while some treatments can reduce symptoms, they cannot stop its progression.

According to UK scientists, more and more evidence indicates that both mental and physical activity can reduce the risk of developing the disease in the first place, or slow down its progression. However, results have not been definitive.

Now, the team from the University of Nottingham has identified a stress hormone that appears to protect the brain from memory changes related to Alzheimer's. The hormone - CRF (corticotrophin-releasing factor) is produced during moderate exercise.

While it is found in high levels in people suffering with anxiety and depression, normal levels of CRF are beneficial to the brain, as it helps the survival of nerve cells. Previous studies have indicated that people with Alzheimer's have lower levels of the hormone.

In tests on animals, the scientists found that those with Alzheimer's and low levels of CRF experienced an improvement in the hormone's level, which in turn had a positive effect on memory, if they repeatedly exercised.

"This is the first time that researchers have been able to identify a brain process directly responsible for the beneficial effects of exercise in slowing down the progression of the early memory decline characteristics of Alzheimer's disease," explained lead scientist, Dr Marie-Christine Pardon.

She added that the study ‘provides further evidence that a healthy lifestyle involving exercise slows down the risk of Alzheimer's disease'. It also offers a new direction for potential treatments.

Details of these findings are published in the Journal of Alzheimer's Disease.

For more information on Alzheimer's, see our Alzheimer's Disease Clinic here