Regular exercise may delay Alzheimer’s in those at high risk of disease Alzheimer’s Society points out that combining results shows that regular exercise can significantly reduce risk of developing dementia

Exercising several times a week may delay brain deterioration in people at high risk for Alzheimer’s disease, according to a new study. People who had accumulation of amyloid beta in the brain – a hallmark of Alzheimer’s disease – experienced slower degeneration in a region of the brain crucial for memory if they exercised regularly for one year, US researchers discovered.

Although exercise did not prevent the eventual spread of toxic amyloid plaques, blamed for killing neurons in the brains of dementia patients, the findings suggest that aerobic workouts can at least slow down the effects of the disease if it is still in the early stages.

Several studies looking at the effect of aerobic exercise – exercise that increases your heart rate – in middle-aged or older adults have reported improvements in thinking and memory, and reduced rates of dementia. Alzheimer’s Society points out that combining the results of 11 studies shows that regular exercise can significantly reduce the risk of developing dementia by about 30 per cent. For Alzheimer’s disease specifically, the most common form of dementia, the risk was reduced by 45 per cent.

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Dr. Rong Zhang, who led the clinical trial at UT Southwestern, in Dallas, that included 70 participants aged 55 and older, said: “What are you supposed to do if you have amyloid clumping together in the brain? Right now doctors can’t prescribe anything. If these findings can be replicated in a larger trial, then maybe one day doctors will be telling high-risk patients to start an exercise plan. In fact, there’s no harm in doing so now.”

Problem solving

The study, published in the Journal of Alzheimer’s Disease compared cognitive function and brain volume between two groups of sedentary older adults with memory issues: one group did at least a half-hour aerobic workout four to five times weekly, and another group did only flexibility training.

Both groups maintained similar cognitive abilities during the trial in areas such as memory and problem solving. But brain imaging showed that people from the exercise group who had amyloid buildup experienced slightly less volume reduction in their hippocampus – a memory-related brain region that progressively deteriorates as dementia takes hold.

Dr Zhang said: “It’s interesting that the brains of participants with amyloid responded more to the aerobic exercise than the others. Although the interventions didn’t stop the hippocampus from getting smaller, even slowing down the rate of atrophy through exercise could be an exciting revelation.”

He said the study merits further research to establish whether fitness can affect the progression of dementia. Scientists across the world, including the UK, are investigating links between fitness and brain health.

A study last year showed that people with lower fitness levels experienced faster deterioration of vital nerve fibers in the brain called white matter. Research in mice has similarly shown exercise correlated with slower deterioration of the hippocampus – findings that prompted Dr Zhang to investigate whether the same effects could be found in people.

He said: “Understanding the molecular basis for Alzheimer’s disease is important. But the burning question in my field is, ‘Can we translate our growing knowledge of molecular biology into an effective treatment?’ We need to keep looking for answers.”