More and more studies are showing how regular exercise benefits the brain, and in particular, the aging brain. What’s less clear is how exactly exercise counters the cognitive decline that comes with aging and diseases like Alzheimer’s.
To find out, for nearly a decade, Ozioma Okonkwo, assistant professor of medicine at the University of Wisconsin School of Medicine and Public Health and his colleagues have studied a unique group of middle-aged people at higher risk of developing Alzheimer’s. Through a series of studies, the team has been building knowledge about which biological processes seem to change with exercise. Okonkwo’s latest findings show that improvements in aerobic fitness mitigated one of the physiological brain changes associated with Alzheimer’s: the slowing down of how neurons breakdown glucose. The research, which has not been published yet, was presented at the annual meeting of the American Psychological Association on Aug. 9.
Okonkwo works with the 1,500 people on the Wisconsin Registry for Alzheimer’s Prevention (WRAP)—all of whom are cognitively normal, but have genes that put them at higher risk of developing Alzheimer’s, or have one or two parents who have been diagnosed with the disease, or both. In the latest study, Okonkwo recruited 23 people from the WRAP population who were not physically active. Eleven were asked to participate in an exercise regimen to improve their aerobic fitness for six months, and 12 served as the control. All had their brains scanned to track Alzheimer’s-related brain changes including differences in how neurons metabolized glucose, since in people with Alzheimer’s glucose breakdown slows. At the end of the study period, the group that exercised more showed higher levels of glucose metabolism and performed better on cognitive-function tests compared to the controls.
We are carrying our research full circle and beginning to demonstrate some causality,” says Okonkwo about the significance of his findings.