Reported June 13 in Neurology, an Alzheimer’s disease risk study from Vanderbilt University Medical Center measures significantly reduced risk associated with healthy lifestyles, including non-smoking, leisure-time exercise, low-to-moderate alcohol consumption, adequate sleep, and healthy diet.
In a group of 17,209 study participants age 65 or older, healthy lifestyles were associated with 11-25% reduced risk of Alzheimer’s disease and related dementias (ADRD). And in composite scoring, the five lifestyles yielded a so-called dose-response association: compared with the lowest-scoring quartile, ADRD risk was reduced 12% in the third-highest-scoring quartile, 21% in the second-highest-scoring quartile, 36% in the top-scoring quartile.
The researchers drew on a racially diverse health disparities research cohort, the Southern Community Cohort Study (SCCS), established in 2001 and comprised predominantly of lower-income adults enrolled at community health centers. Some two-thirds of SCCS participants are Black. (The SCCS is jointly conducted by researchers at VUMC and Meharry Medical College.)
“While associations between lifestyles and ADRD risk had been found previously, those studies have predominantly been conducted among white adults or individuals with middle or high levels of income and education,” said epidemiologist Danxia Yu, PhD, assistant professor of Medicine, who led the study with Jae Jeong Yang, PhD, MPH, an epidemiology research fellow.
“Lower-income Black adults in particular have historically been underrepresented in studies examining associations between lifestyle and dementia,” Yu said. “Especially considering the greater burden of dementia that’s seen in Black adults and individuals of lower income, our study helps mend something of a gap in the research literature.”
The study included 1,694 subjects diagnosed with ADRD during follow-up. Beneficial associations of healthy lifestyles were observed regardless of race, other sociodemographic factors, or pre-existing health conditions.
“Our results suggest that helping disadvantaged populations find their way to healthier lifestyles, for example through improving the availability, accessibility and affordability of health lifestyles, could go a long way toward reducing ADRD risk and health disparities in our society,” Yu said.
Based on health guidelines, on each of the five lifestyle dimensions participants were scored as “healthy,” 2; “intermediate,” 1; or “unhealthy,” 0. Taking the five lifestyles in isolation, “healthy” versus “unhealthy” scores were associated with reduced risk of 25% for 7-9 hours of sleep a night versus 9 hours or more; 19% for low-to-moderate alcohol consumption versus none; 15% for high-quality versus low-quality diet; 13% for never having smoked tobacco versus currently smoking; 11% for getting more than 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week, versus none.
Also on the study are Laura Keohane, PhD, MS, Xiongfei Pan, PhD, MSc, Kyle Braun, MPH, Xiao-Ou Shu, MD, PhD, Loren Lipworth, ScD, Ruiqi Qu, MPH, Mark Steinwandel, BBA, Qi Dai, MD, PhD, Martha Shrubsole, PhD, Wei Zheng, MD, PhD, MPH, and William Blot, PhD.
The study was supported by the National Institutes of Health (CA202979).
