Physical activity promotes changes in the brain that may protect high-risk individuals against cognitive decline, according to a new study. That includes the development of Alzheimer’s disease, the world’s most common type of dementia and one that needs no introduction.
The new study included both people who carry a high-risk gene for Alzheimer’s disease, and other healthy older adults without the gene. Those with the gene were put biologically at greater risk of Alzheimer’s, so that begged the question: could exercise held shield even these people from the disease?
The results showed that even if you are at genetic risk for Alzheimer’s disease, the benefits of exercise to your brain function might be even greater than for those who do not have that genetic risk. It’s another clear indication that we have control over our health-related fate.
While evidence already shows that exercise is linked with maintaining strong cognitive function across a life span, most of this research has been done with healthy people. But it failed to account for those at high risk of Alzheimer’s.
Researchers compared brain activation during memory processing in four separate groups of healthy 65- to 85-year-olds. The level of risk was defined by whether an individual carried the apolipoprotein E-epsilon4 (APOE-ϵ4) gene. Physical activity status was defined by how much and how often the participants reported exercising.
The researchers used MRIs to measure brain activation of the participants while they performed a mental task involving discriminating among famous people. This particular test is very useful, as it engages a wide network called the “semantic memory system.” Here, 15 different functional regions of the brain are involved.
In the study groups of those carrying the gene, individuals who exercised showed greater brain activity in memory-related regions than those who were sedentary. Also interesting, physically active people with the gene had greater brain activity than those who were physically active but not gene carriers.
It could be that using more areas of the brain may serve in itself as a protective function in the face of Alzheimer’s disease.
What all this means is that, even if you are told you are at genetically higher risk of dementia, you can still help yourself. Get at least a half-hour of exercise a day and your mind could stay sharper.