Summary: Regular moderate exercise may help prevent or slow the physical brain changes linked to Alzheimer’s disease in people who are genetically at risk.
Source: APA
Moderate exercise benefits memory as people age and may also reduce the development of physical signs of Alzheimer’s disease—known as biomarkers—in individuals at elevated risk, according to research presented at the annual convention of the American Psychological Association.
“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 better memory and cognitive functioning,” said Ozioma Okonkwo, PhD, an assistant professor of medicine at the University of Wisconsin School of Medicine and Public Health, who presented results from several related studies.
The research drew on participants in the Wisconsin Registry for Alzheimer’s Prevention, an ongoing observational study of people whose parents had probable Alzheimer’s dementia. The analysis described here involved 317 cognitively healthy registrants who were between 40 and 65 years old when they enrolled. The registry collects detailed baseline information on biological, health, and lifestyle factors linked to Alzheimer’s risk and follows participants with repeat assessments every two to four years.
Each participant completed a questionnaire about physical activity and underwent neuropsychological testing along with brain imaging to measure several biomarkers associated with Alzheimer’s disease. When researchers compared participants younger than 60 with older adults within the cohort, they observed the expected pattern: cognitive performance tended to decline with age, and biomarkers commonly associated with Alzheimer’s increased. Crucially, those age-related changes were substantially smaller among older adults who reported engaging in at least 30 minutes of moderate exercise on most days (roughly five days per week).
Okonkwo emphasized the practical implication: “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.” The finding suggests that consistent physical activity in midlife may help preserve brain health for people already at elevated risk.
In a second analysis, researchers examined data from 95 registry participants who had been assigned polygenic risk scores. These scores reflect the combined contribution of multiple genetic variants associated with Alzheimer’s disease. As expected, participants with higher genetic risk scores generally showed greater evidence of Alzheimer’s-related biomarkers. However, the researchers found that higher levels of aerobic fitness—measured using an index that incorporated age, sex, body mass index, resting heart rate, and self-reported physical activity—appeared to weaken the relationship between genetic risk and biomarker burden. In other words, people with greater aerobic fitness showed less biomarker change even when their genetic risk was higher.
A third study within the same program used MRI scans from 107 participants and measured aerobic fitness directly through a treadmill test that determined each person’s oxygen uptake efficiency slope, a physiological measure of aerobic capacity. Consistent with the other findings, white matter hyperintensities—an MRI indicator frequently linked to aging and Alzheimer’s risk—tended to increase with age. Participants with higher aerobic fitness showed smaller increases in these white matter changes compared with less fit peers, suggesting a protective association between better cardiorespiratory fitness and brain structure.
Taken together, these studies indicate that physical activity and aerobic fitness may attenuate the harmful effects of both aging and genetic vulnerability on brain biomarkers and cognitive performance among people at risk for Alzheimer’s disease. Okonkwo noted that while these observational results are encouraging, confirmation through prospective, controlled intervention studies would strengthen the evidence that regular moderate exercise can serve as an effective preventive strategy—particularly for individuals with family histories or genetic indicators of risk.
Source:
APA
Media Contacts:
Jim Sliwa – APA
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The image is in the public domain.
Original Research:
The study was presented at the 2019 American Psychological Association Convention in Chicago.