Exercise Shown to Stave Off Alzheimer’s in High-Risk Subjects
by Laura Shin For SmartPlanet:If you were told that you had a genetic predisposition to develop a disease, you might understandably resign yourself to getting it someday.But a new study offers hope that, when it comes to our genes, we have more control over our destinies than we think. And all it comes down to is something as simple as a daily jog or walk.The studyResearchers at Washington University in St. Louis’s Knight Alzheimer’s Disease Research Center conducted a study of 201 people, some of whom had family histories of Alzheimer’s and others who didn’t. None of them showed outward signs of the disease at the beginning of the study.They then scanned the subjects’ brains to look for amyloid plaques, deposits that are correlated with memory loss from Alzheimer’s. They also checked the volunteers’ APOE, a gene that can cause a 15 times higher risk of Alzheimer’s in patients who carry the variant called e4. E4 carriers also show symptoms of dementia in their late 60s, rather than in their early 80s, as non-e4 carriers do. In the study, 56 volunteers had the e4 variant.Lastly, they asked the subjects about their exercise habits over the previous 10 years.As in some previous studies, those who exercised more had a smidgen fewer amyloid plaques than those who didn’t. But the difference was not statistically significant.However, the group with the e4 variant was a different story. Among them, those who exercised had dramatically less plaques build-up in the brain compared to those who did not.ConclusionAs the study authors wrote in the study, published in the Archives of Neurology, a “physically active lifestyle may allow e4 carriers to experience brain amyloid levels equivalent to e4-negative individuals.”Dr. Denise Head, lead author and an associate professor of psychology at Washington University, says that while the study showed that exercise could lessen the accumulation of plaque on the brain and potentially on the development of Alzheimer’s in those with the genetic predisposition, it’s not yet clear whether exercise can also provide benefits after the plaques have built up.But, Dr. Head points out, mice that were bred to have memory loss have been shown to benefit from beginning a running program, and to experience less dementia than mice who didn’t begin the program.