Exercise may help people at risk of dementia

A small study found that exercise reduced the brain shrinkage rate in people at risk of Alzheimer's disease.
02 October 2019


Exercise was found to help reduce the brain shrinkage rate in people at risk of Alzheimer's disease, even though the same effect wasn’t observed in people who didn’t have the same risk indicators...

A small research study published in the Journal of Alzheimer’s Disease looking at whether exercise could be an effective therapy for Alzheimer’s, found that it may help slow down the degeneration of the brain for people whose brain shows early signs of the disease.

The study followed 70 patients with mild cognitive impairment of their memory over a period of a year, who were split into two groups doing two types of exercises several times a week. The first group was asked to do aerobic exercise, also known as cardio, which aims to increase the heart rate, while the second group was doing less intense stretching exercises.

Interestingly, memory and thinking improved over time for most of the people in the study, and without any significant difference between the two groups, which confirms previous findings that exercise in older age helps improve cognitive function. However, this improvement didn't also translate into as clear-cut physical changes in the brain.

Besides testing the memory and cognition of the participants, the researchers also looked at changes in brain volume and the quantity of beta-amyloid over time. Beta-amyloid is a protein whose accumulation between neurons disrupts their normal functioning and is associated to the development of Alzheimer’s disease, while brain volume reduction, also known as brain shrinkage or atrophy, is also an indicator for dementia. A certain degree of brain shrinkage and neuron loss is fairly common with age, even in people who are cognitively healthy, but this atrophy is faster in people with mild cognitive impairment, and then even faster in those who ultimately progress to develop Alzheimer’s disease.

The researchers found that cardio exercise slowed down the rate at which the hippocampus, a region of the brain important for memory, was shrinking, but only for patients that already had small accumulations of beta-amyloid protein. The authors suggest that this may be because the plasticity of the hippocampus in response to exercise may be sensitive to the presence of brain amyloid in this type of patients, but the exact mechanism remains to be investigated further.

While this is a small study, the researchers are working on a larger project investigating the relationship between exercise and dementia, and whether exercise can be used as a therapy for people who are at risk of Alzheimer’s, so before the signs of the disease are visible.

Katy Stubbs, from Alzheimer’s Research UK, commented that this study “adds a new piece to our understanding of not just our heart health, but also our brain health. While there have been many studies that have indicated that being physically active could reduce the risk of dementia, we haven’t yet looked at very much at whether it can slow down the changes that might be happening in the early stages of the condition.”

Being able to diagnose, and then treat, different types of dementia, including Alzheimer’s, as early as possible, is one of the current challenges in the dementia research field.

“That’s really the window of opportunity for when, once researchers have developed treatments that can target some of the biological changes in the brain that cause dementia, we need to pick them early enough so that the treatments stand any chance of working,” adds Katy.


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