5 evidence-based ways to cut your risk for Alzheimer’s

By Naveed Saleh, MD, MS
Published July 21, 2020

Key Takeaways

In 2018, an estimated 5.7 million Americans lived with Alzheimer dementia (AD), with this number expected to triple over the next 30 years. Clinical trials have demonstrated that treatment fails to change the course of the disease, highlighting a need for preventive strategies. 

But what would that look like?

Lifestyle factors

A study published in Neurology, which incorporated longitudinal findings from the Chicago Health and Aging Project (CHAP) and Rush Memory and Aging Project (MAP), evaluated the effect of 5 healthy lifestyle choices as preventive interventions.

The researchers calculated lifestyle scores for study participants based on the number of healthy lifestyle factors each participant followed. The factors were:

  • Nonsmoking

  • ≥150 min per week moderate/vigorous-intensity physical activity

  • Light to moderate alcohol consumption

  • High-quality Mediterranean-DASH Diet Intervention for Neurodegenerative Delay 

  • Engagement in late-life cognitive activities.

Risk for Alzheimer disease

The team found that having more of these lifestyle factors  predicted a lower risk of AD. Specifically, older adults who had four to five of these factors had a 60% decreased risk of developing AD compared with those who had none or one.

These correlations held despite risk factors for AD, such as with white participants who carried the APOE e4 allele, which not only increases risk of AD, but also lowers the age of onset. 

During a median follow-up period of 5.8 years in the CHAP study and 6.0 years in the MAP study, the pooled hazard ratio across the two cohorts was 0.73 (95% CI 0.66–0.80) for each additional lifestyle factor. The risk of AD was 37% lower in those with 2 to 3 healthy lifestyle factors compared with those with none or one.

“From these findings and the fact that the lifestyle factors we studied are modifiable and in direct control of the individual, it is imperative to promote them concurrently among older adults as a strategy to delay or prevent Alzheimer dementia,” the authors wrote.

Previous observational studies have shown that individual lifestyle factors, including diet, exercise, and cognitive engagement, can affect the risk of developing AD. However, lifestyle factors are often related to one another, with resultant cluster effects. 

Although exact mechanisms explaining the link between lifestyle and AD risk are unclear, the researchers provided some insight. “A number of studies indicate that healthier diets rich in nutrients and vitamins, physical exercise, and smoking abstinence could initiate a chain of metabolic and molecular alterations that presumably inhibit inflammation and oxidative stress and may reduce amyloid accumulation, neuritic plaques, and neurofibrillary tangles in the brain, but insights into the specific pathways involved are limited,” they wrote.

The researchers did not include BMI as a variable because of the complex relationship between weight as both a cause and risk for dementia. Previous high-powered research has shown an inverse relationship between obesity and dementia risk, which opposes the hypothesis that obesity increases that risk. Nevertheless, the researchers considered BMI as a covariate.

The authors acknowledge certain study limitations. First, the study uses questionnaires to gather data. And, although the questionnaires were validated, diet and physical activity were self-reported.  Second, lifestyle factors were analyzed at baseline only, with changes over time not assessed. Third, although the level of which each of these lifestyle factors affects the risk of AD is different, the factors were not weighted differently due to limitations in sample size, with the researchers hypothesizing that clustered factors affect the overall  lifestyle health score of the individual. Fourth, although the researchers excluded events that transpired during the initial 2.5 years of follow-up, reverse causality could play a role. 

Strengths of the current study include its generalizability across age and race. Additionally, in both cohorts, the diagnosis of AD was established via regular neuropsychological testing and structured neurological assessments.

“A healthy lifestyle as a composite score is associated with a substantially lower risk of Alzheimer dementia,” the authors concluded.

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