Recent research looking at the impact of lifestyle practices on dementia shows that even in people with high genetic risk, good nutrition, regular exercise, minimal alcohol intake, and not smoking lowered their likelihood of developing dementia later in life. The article, published in JAMA, described a study of almost 200,000 people which found a statistically significant difference in risk for later dementia between those with a healthy lifestyle and those with a less healthy one. Researcher Elzbieta Kuźma, at the University of Exeter Medical School, said, “This research is exciting in that it shows there are actionable things we can do to try to counteract genetic risk for dementia.”
A study from the Rush Memory and Aging Project in Chicago found similar results. Participants who had at least four of five healthy lifestyle habits – a healthy diet, at least 150 minutes a week of moderate to vigorous physical activity, light to moderate drinking, no smoking, and engaging in mentally stimulating activity – reduced their risk of developing Alzheimer’s by 60% compared to people who had only one of those habits. And regardless of how healthy they were at the beginning of the study, participants who added one more healthy habit of the five reduced their risk of Alzheimer’s by 22%.
An article in the July issue of JAMA Neurology by Jennifer S. Rabin and colleagues reported that daily physical activity may delay onset of Alzheimer’s disease. Older adults who were more physically active had less beta-amyloid accumulation and less gray matter volume loss. What was interesting is that these associations were significant even after adjusting for vascular risk.
Laura Baker of the Wake Forest School of Medicine studied 70 patients who had mild cognitive impairment and diabetes, both of which increase the risk of Alzheimer’s. Participants did either supervised aerobics, usually on a treadmill, or stretching for 45 – 60 minutes, four times a week. Exercisers had better blood flow in the memory and processing centers of their brains, and had improvement in attention, planning, and organizing abilities (executive function), in addition to lower levels of tau (a protein associated with Alzheimer’s).
In yet another study, Dr. Liu-Ambrose of the University of British Columbia in Canada and colleagues had 71 people with vascular dementia (caused by “silent” or “mini-strokes”) either exercise or continue normal activities. She found that those who walked at a moderately brisk pace for an hour, three times a week not only did better on memory and attention tests, but lost weight and lowered their blood pressure.
Research also shows that some lifestyle practices increase dementia risk. Smoking is associated with cognitive decline, even at mid-life, and alcoholism in women has been shown to significantly increase risk of dementia later in life. Another study recently reported the effects of prolonged exposure to dirty air, or pollution, and found a significant impact on cognitive abilities, especially in older men. The data came from a longitudinal survey in China, which compared the cognitive test scores of nearly 32,000 people older than 10 over a four-year period against their exposure to air pollution. The decline in verbal scores were particularly pronounced among older, less-educated men.
Despite the promising outcomes of this research, it is important to remember that some people will develop dementia even if they follow healthy lifestyle practices. However, Maria C. Carrillo, the Alzheimer’s Association chief science officer states that, “While there is no proven cure or treatment for Alzheimer’s, a large body of research now strongly suggests that combining healthy habits promotes good brain health and reduces your risk of cognitive decline.”