Alzheimer’s Dementia Onset: Study Examines the Impact of Lifestyle Factors on Life Expectancy
A Note from Dr. Robert Stout, CRL Chief Scientific Officer & Co-Founder
The below commentary from Michael Fulks, MD, is timely and pertinent to our research at CRL. In studying Alzheimer’s disease causes, risks, and mortality impact, we’ve found enlightening new data on the interaction between amyloid-β and changes in blood flow. We have seen that changes in the vascular endothelial may be a driver for the development of Alzheimer’s disease. Read on for more details from Dr. Fulks.
Are the extra years of life associated with a healthy lifestyle still “good years,” or are they consumed by Alzheimer’s dementia?
That is the question and a fear we all contemplate because of the progressively tighter association between advancing age and Alzheimer’s dementia, resulting in 37% of people being demented by ages 90+. A February 2022 study by K. Dhana, et al. appearing recently in BMJ helps alleviate those fears. The authors used data from the Chicago Health and Aging project cohort to follow participants age 65+, analyzing positive modifiable lifestyle factors against the outcomes of life expectancy with and without Alzheimer’s dementia. Factors included healthy diet, cognitive activities, moderate to vigorous physical activity, not smoking, and light to moderate alcohol consumption.
The authors found that women aged 65+ with 4-5 of the positive lifestyle factors lived 3 years longer than those with 0-1 factors but averaged only 2.6 years living with Alzheimer’s compared to 4.1 years for those fewer positive factors. Men aged 65+ with 4-5 positive lifestyle factors lived 5.7 years longer than those with 0-1 factors but spent only 1.4 years with Alzheimer’s compared to 2.1 years. The study found that on average, healthy lifestyle factors for both sexes resulted in a longer life but substantially fewer years with Alzheimer’s dementia. The relative differences in time with Alzheimer’s continued to increase at ages older than 65.
This begs the question: the pathologic changes of Alzheimer’s dementia are not influenced by the lifestyle changes, so how can this be? One obvious concern with the study is that those with early unrecognized cognitive difficulties are less likely to engage in the positive lifestyle factors – namely, cognitive activities – which could falsely link less positive lifestyle to the development of dementia. But another likely reason is the increasingly recognized association between cardiovascular risk factors to diagnosed Alzheimer’s dementia. It is not as a direct cause of the actual Alzheimer’s pathology, but a cause of an underappreciated vascular dementia component to the resultant combined dementia.
For perspective, a healthy lifestyle is almost like a free lunch: both a longer life and less risk of dementia, but you need to keep active in mind and body to achieve them.
About the Author
Michael Fulks, MD, Consulting Medical Director, is board-certified in internal and insurance medicine. After leaving practice, he served as a medical director, creating or editing several underwriting manuals and preferred programs. More recently, Mike has consulted for CRL participating in its mortality research on laboratory test results, BP and build, and in the development of risk-scoring tools for laboratory and non-laboratory data.