May 25th, 2017
What if there were a way to significantly reduce your odds of developing Alzheimer’s-related dementia, with no side effects? There just may be, and it has been around forever: exercise. Decades of studies show that physical activity has a host of health benefits, including reduced risk of cardiovascular disease and diabetes. Now, research by Dr. Ozioma Okonkwo at the University of Wisconsin, Madison finds that exercise can also help prevent the brain changes and cognitive declines associated with Alzheimer’s. That is very promising news for adults with a family history of the disease who have long feared that their long-term prognosis is a foregone conclusion.
Okonkwo’s work targets the twin goals of improving early identification of Alzheimer’s and identifying potential strategies for prevention. Prevention is especially important for a disease like Alzheimer’s that has no known cure and few effective treatments. “We believe that to have a real impact on the looming epidemic [of Alzheimer’s], we need to intervene much earlier than when people have symptoms, given the state of the science now,” he explains. He and his colleagues therefore study people who have little or no cognitive impairment but who are at risk based on family history. Advancements in brain imaging have allowed them to track the development of brain pathology over time, even in the absence of behavioral symptoms.
Okonkwo has used that technology to conduct multiple studies on the preventive benefits of exercise. These studies have shown that people who are fit and active have more of what he calls brain resilience – they have “a slower rate of accumulation of pathologies in the brain” and even when brain changes do occur, they cause less cognitive impairment than is typical. The longer the person has been active, the more her brain benefits. But the good news is that people who start becoming active in mid-life do see improvements in brain resilience. Okonkwo and his colleagues see an opportunity there, and they are now conducting randomized controlled trials of exercise interventions for adults who enter their studies with sedentary lifestyles. The results have been encouraging. In a study that assigned half the participants to a regular aerobic exercise routine for six months, the exercisers developed more brain resilience than the non-exercisers – and their mood improved, too. As the next step in this work, Okonkwo’s lab is part of a new multi-site trial called EXERT, which is testing the impact of exercise in adults with mild cognitive impairment to see if the benefits also accrue to people who are already in the early stages of dementia.
Okonkwo is passionate about translating his research into action, and he believes it is important to engage with the community to make that happen. In the EXERT trial, participants are given memberships to local YMCAs, and the study’s exercise sessions are held right at those centers, because the researchers understand that some people don’t want to come to an ivory tower medical center to work out, and the ones who do often stop when the study is over, because they no longer have the structure or consistent routine. Okonkwo has added an extra benefit to make working out easier and more appealing: he has extended the benefit of YMCA membership to participants’ partners. He recognizes that people are more likely to exercise when they have encouragement and companionship. Plus, he believes it’s important to “change the community, not just the person within the community.”
Okonkwo is also looking at genetic markers in Alzheimer’s, not just those that identify risk but also two that appear to protect against the brain changes and symptoms associated with the disease. When one of these genes is “switched on,” it seems to override another gene that strongly predisposes people to the disease and its symptoms. These findings are promising, but Okonkwo points out the immense complexity of genetics and says scientists are not at the point of having an effective genetic therapy for treating or preventing Alzheimer’s.
In the meantime, Okonkwo feels confident about recommending exercise for adults at risk of developing dementia – and for all adults. “It is not yet known for a fact that we can completely prevent dementia, but we also know that these preventive strategies [like exercise] do not cause harm when done right,” he points out – and they have other health benefits. “It’s a win-win,” he says, and that’s a rarity for people facing the possibility of Alzheimer’s Disease.
Ozioma Okonkwo is a recipient of the Federation of Associations in Behavioral & Brain Sciences (FABBS) Foundation Early Career Impact Award, which will be presented during the annual meeting of the National Academy of Neuropsychology.