January 8, 2019

expert reaction to role of exercise-induced hormone on memory in Alzheimer’s models

Research published in Nature Medicine demonstrates that hormones released during exercise are potentially capable of opposing synapse failure and memory impairment in Alzheimer’s disease.

Prof Lawrence Rajendran, van Geest Professor of Dementia Research, Deputy Director, UK Dementia Research Institute, King’s College London, said:

“The study encompasses data from cell culture, mice and also patients and while most of the paper is mostly molecular in nature, it does have potential implications for therapy.

“This exciting paper does two things:

1)  emphasises what we intuitively already believe: that exercise may play a role in staving off memory loss in Alzheimer’s disease. This is the first time the mechanistic role of irisin has been demonstrated in an Alzheimer’s disease mouse model and may hint to a mechanism by which this effect occurs.

2)  suggests a possibility for exercise-mimetics to be potential therapies for Alzheimer’s disease.

“If this well performed study is reproducible across cohorts and can be translated for human therapy, it indeed will be a milestone in Alzheimer’s disease research.”

Dr Rosa Sancho, Head of Research at Alzheimer’s Research UK, said:

“We know that physical activity is linked to better brain health as we age, and this research highlights a biological mechanism that may contribute to this beneficial effect. These interesting findings present a new avenue for future research that could help us better understand how exercise programmes could be targeted to provide the greatest benefit to brain health.

“There are many people either with dementia or at high risk of dementia, who have health conditions that make regular exercise more difficult. Drugs designed to target the hormone identified in this research could potentially bring some of the benefits of physical activity to people who may be less able to exercise.

“This is very early-stage research and while some of the findings emerge from examination of brain tissue from people with Alzheimer’s, the insights gained from experiments with mice will need to be followed up in studies involving people.”

Dr James Pickett, Head of Research at Alzheimer’s Society, said:

“Although this study was only in mice, it adds to mounting evidence of the relationship between lifestyle factors, like physical fitness, and dementia. This is a promising avenue for more research and potentially new therapies in future.

“We know that exercise can decrease a person’s risk of developing dementia, but still have lots to learn about its effect on cognitive decline – for example, we need to know how this hormone gets into the brain, how it works, whether it is effective in people, and whether it affects men and women in the same way – which is why we’re funding a long-term study of 700 middle-aged people at risk of dementia to better understand these links.

“With no new dementia drugs in over 15 years, we urgently need to find ways to tackle this devastating disease. We know that exercise not only helps people with dementia to manage certain side-effects but also reduces the risk of developing the condition, which gives us all more motivation for those New Year’s Resolutions to get fit and healthy.”

Prof John Hardy FMedSci, Professor of Neuroscience, UCL, said:

“Moderate exercise is, of course, good for people of all ages and there has been circumstantial evidence suggesting exercise specifically helps memory function in Alzheimer sufferers.  This report seeks to show a mechanism for such an effect.  On its own, I do not find it convincing: memory tests in transgenic mice have not predicted memory test outcomes in Alzheimer patients and direct measurements in patients are always subject to confounds concerning cause and effect (i.e. people who are doing better exercise more).”

Prof Martin Rossor, Professor of Clinical Neurology, UCL and NIHR National Director for Dementia Research, said:

“There is increasing evidence that exercise can improve thinking and memory and more recently that this can be seen in people with a diagnosis of Alzheimer’s disease. This is an important study that explains how those beneficial effects of exercise might come about. Beneficial effects in animal models of Alzheimer’s disease often fail to translate to humans but there are some encouraging avenues to explore.”

‘Exercise-linked FNDC5/irisin rescues synaptic plasticity and memory defects in Alzheimer’s models’ by Mychael Lourenco et al. was published in Nature Medicine at 16:00 UK time on Monday 7 January 2019.

All our previous output on this subject can be seen at this weblink: http://www.sciencemediacentre.org/tag/alzheimers/

Declared interests

Prof Lawrence Rajendran: No declarations of interest.

Dr Rosa Sancho: No conflicts of interest.

Prof John Hardy: Prof Hardy is a member of the SMC Advisory Board. No conflicts of interest.

Prof Martin Rossor: No declarations of interest.

None others received