Regular exercise may reduce the risk of Alzheimer’s Disease

By Dr. Ananya Mandal, MDAug 16 2019

At the 2019 American Psychological Association convention, a team of researchers presented their work that showed that regular exercise could help prevent cognitive decline seen in neurodegenerative diseases such as Alzheimer’s.

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Dr. Ozioma Okonkwo from University of Wisconsin School of Medicine and Public Health, said, “Our research shows that in a late-middle-age population at risk for Alzheimer's disease, physically active individuals experience fewer age-related alterations in biomarkers associated with the disease, as well as memory and cognitive functioning.”

The researchers used data from the Wisconsin Registry for Alzheimer's Patients; an ongoing study that includes over 1500 individuals whose parents have been diagnosed with a form of dementia.

Each participant received a health check followed by a detailed cognitive check was at the start of the study and again every two to four years. Lifestyle factors, including dietary habits, were also recorded for each of the participants. Each of the 317 individuals involved in the study were diagnosed as ‘cognitively healthy’ at the start of the study. All participants were between 40 and 65 years of age at the start of the study.

At each follow-up appointment, participants underwent detailed neuropsychological testing and brain scans. This was used to study the levels of biomarkers that are known to be associated with the development of Alzheimer’s disease.

When the team had gathered sufficient data from the participants, they compared the information from the participants younger than 60 years with those who are older. As expected, cognitive ability declined with age and Alzheimer’s biomarkers rose with age.

However, participants who engaged in at least 30 minutes of exercise each day showed significantly better cognitive ability, compared to others in their age group. The data suggested that people who exercised for 30 minutes or longer each day could delay the cognitive decline and related biomarkers associated with Alzheimer’s disease, compared to those who did not exercise.

The most interesting part of our research is that we now show evidence that lifestyle habits - in this case regular, moderate exercise - can modify the effect of what is commonly considered a non-modifiable risk factor for Alzheimer's, in this case aging.”

Ozioma Okonkwo

This is not the first study from Okonkwo and his team on Alzheimer’s disease and exercise. In another study, the team assigned polygenic risk scores to 95 individuals belonging to the same registry.  A polygenic risk score is determined by the number of genetic factors associated with Alzheimer’s disease that a person carries. These genetic factors were quantified and each of the participants was scored according to the level of genetic risk they carried.

In this study, the team looked at the effects of exercise, especially aerobic fitness in determining the changes in the total risk of getting Alzheimer’s disease compared to the predictability of genetic risk factors alone.

Results revealed that persons who were at a greater genetic risk of Alzheimer’s disease also had a higher level of the biomarkers for this condition. Among persons who had a greater aerobic fitness, the effect of the genes w found to be weaker. The researchers accounted for all other factors including age, gender, body mass index, other activity and heart rate at rest.

The results showed that good aerobic fitness was linked to a reduced risk of Alzheimer’s disease and lower biomarkers, despite having a higher genetic risk.