Exercise could slow down the devastating effects of Alzheimer's disease

Exercising several times a week could delay brain deterioration in people at high risk for Alzheimer's disease, according to a study that scientists say deserves additional research to determine if fitness can affect the progression of dementia.

Research conducted by UT Southwestern has shown that people with beta-amyloid accumulation in the brain – characteristic of Alzheimer's disease – showed slower degeneration in a memory-critical brain area if they were to do so. exercise regularly for one year.

Although exercise has not prevented the possible spread of toxic amyloid plaques responsible for the death of neurons in the brains of patients with dementia, the results suggest an intriguing possibility that aerobic workouts can at least slow down the effects of the disease if an intervention takes place in the early stages.

"What are you supposed to do if you have amyloids that get stuck in the brain? At the moment, doctors can not prescribe anything," said Dr. Rong Zhang. , who led the clinical trial with 70 participants aged 55 and over. "If these results can be replicated in a larger trial, then maybe one day the doctors will tell high-risk patients to start an exercise program." has no trouble doing it now. "

Reduced brain atrophy

The study published in the Diary of Alzheimer's disease compared cognitive function and brain volume between two groups of sedentary older adults with memory problems: one group did aerobic exercise (at least one workout session). half an hour four to five times a week) and another group did only flexibility training.

Both groups retained similar cognitive abilities during the course of the test in areas such as memory and problem solving. However, brain imaging showed that people in the exercise group who had accumulated amyloid had a slightly lower volume reduction than their hippocampus, a region of memory-related brain that was deteriorating. gradually as dementia settles.

"It's interesting to note that the brains of participants with amyloid have responded better to aerobic exercise than others," said Dr. Zhang, who conducted the trial at the University of Ottawa. Institute of Exercise and Environmental Medicine. "Although interventions have not prevented the hippocampus from becoming smaller, even slowing the pace of exercise atrophy could be an exciting revelation."

However, Dr. Zhang noted that further research was needed to determine whether or not the reduced atrophy rate was beneficial for cognition.

Elusive answers

The search for dementia therapies is becoming increasingly urgent: more than 5 million Americans are suffering from Alzheimer 's disease and this number is expected to triple by 2050.

Recent research has helped scientists better understand the molecular genesis of the disease, including the discovery by UT Southwestern published last year that guides efforts to detect disease before the onset of symptoms. Yet the billions of dollars spent trying to prevent or slow dementia have not given any proven treatment that would allow patients to be diagnosed early.

Fitness and brain health

Dr. Zhang is part of a group of scientists around the world who are trying to determine if exercise is the first therapy of this type.

His latest research is based on numerous studies suggesting links between fitness and brain health. For example, a study conducted in 2018 showed that people with low fitness levels experienced a faster deterioration of the vital nerve fibers of the brain called white matter. Research on mice also showed that exercise correlated with a slower deterioration of the hippocampus – discoveries that led Dr. Zhang to investigate whether the same effects could be observed in humans. ;man.

"I am excited about the results, but only to a certain extent," said Dr. Zhang. "This is a proof-of-principle study, and we can not yet draw definitive conclusions."

Extended search

Dr. Zhang is leading a five-year national clinical trial aimed at deepening the potential correlations between exercise and dementia.

The trial, which includes six medical centers across the country, involves more than 600 elderly people (aged 60 to 85 years old) at high risk of developing Alzheimer's disease. The study will determine whether aerobics exercises and taking specific medications to reduce high blood pressure and cholesterol can help preserve brain volume and cognitive abilities.

"Understanding the molecular basis of Alzheimer's disease is important," said Dr. Zhang. "But the burning question in my field is:" Can we translate our growing knowledge of molecular biology into effective treatment? "We have to keep looking for answers."

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