The ‘workout’ jab to stave off Alzheimer’s

A BRAIN-BOOSTING injection which boasts the benefits of a workout could be developed for those at risk of Alzheimer’s.

Exercise has been widely hailed as a positive step in keeping the disease at bay – and irisin, a hormone released during exercise, is now thought to be the key.

In a joint study by researchers at the Federal University of Rio de Janeiro and Queen’s University in Canada, mice were bred to have dementia symptoms.

Researchers tested their memories by putting them in a box with a strange toy brick and one they had already seen. Normal mice would ignore the familiar object to sniff and paw the new one, while mice bred to have dementia symptoms explored both bricks as they did not remember the old one.

But the memory-impaired mice behaved like the normal mice when injected with irisin, or after hour-long swimming sessions five days a week. Their memory problems returned when irisin was inhibited during exercise using a virus.

Dr Fernanda Felice, who produced the study published in the journal Nature Medicine, said: ‘If researchers are able to move to human clinical studies, in the future there could be an injection of irisin which could help elderly people who cannot exercise because of health problems like heart disease and arthritis.’ It is hoped that the irisin could be administered as an injection or in pill form, and would work to prevent the disease getting worse in those already affected.

Its importance in protecting memory was highlighted when researchers found very low levels of the hormone in the spinal fluid of 20 people with Alzheimer’s disease. Levels were also low in the brains of 10 people who died from the condition, which affects around 850,000 people.

Lawrence Rajendran, professor of dementia research at King’s College London, hailed the trial and said that if it can be translated to humans it will be a ‘milestone in Alzheimer’s disease research’.