A study of almost 2500 participants has found that a healthy lifestyle is associated with longer life expectancies as well as extra years without Alzheimer’s.
The findings, suggest US and Swiss researchers, might help health professionals, policy-makers and stakeholders to plan future healthcare services, costs and needs, according to the researchers.
As a part of the study, the participants from within the Chicago Health and Aging Project (CHAP) completed detailed diet and lifestyle questionnaires and a healthy lifestyle score was developed based on: a hybrid Mediterranean-DASH Diet (a diet rich in whole grains, green leafy vegetables and berries, and low in fast/fried food and red meats); late-life cognitively stimulating activities; at least 150 minutes a week of physical activity; not smoking; and low to moderate alcohol consumption.
Cognitive activities included reading, visiting a museum or doing crosswords.
For each lifestyle factor, participants received a score of 1 if they met the criteria for healthy, and 0 if they did not. Scores from five lifestyle factors were summed to yield a final score ranging from 0 to 5. A higher score indicated a healthier lifestyle.
After taking account of other potentially influential factors, including age, sex, ethnicity and education, the researchers found that, on average, the total life expectancy at age 65 in women and men with a healthy lifestyle was 24.2 and 23.1 years, respectively. But for women and men with a less healthy lifestyle, life expectancy was shorter — 21.1 and 17.4 years.
For women and men with a healthy lifestyle, 10.8% (2.6 years) and 6.1% (1.4 years) of the remaining years were lived with Alzheimer’s respectively, compared to 19.3% (4.1 years) and 12.0% (2.1 years) for study participants with a less healthy lifestyle.
At age 85, these differences were even more notable.
While the study was population-based with long-term follow-up, this was an observational study, and as such, cannot establish cause.
The researchers pointed to some other limitations, for example, lifestyles were self-reported, possibly leading to measurement error, and the estimates provided in this study should not be generalised to other populations without additional research and validation.
However, the researchers concluded: “This investigation suggests that a prolonged life expectancy owing to a healthy lifestyle is not accompanied by an increased number of years living with Alzheimer’s dementia.”
In a linked editorial, a University of Michigan researcher highlights the study’s “important implications for the wellbeing of aging populations and for related public health policies and programs”.
She suggested that the development and implementation of intervention programs to reduce the risk of Alzheimer’s disease and other dementias is critically important in global efforts to reduce pressure on stressed healthcare systems, healthcare workers, and both paid and unpaid carers.
“Promoting greater engagement in healthy lifestyles may increase dementia-free life years — by delaying the onset of dementia without extending life years spent with dementia,” she said.