Combination of Healthy Lifestyle Factors Reduces Alzheimer Risk

Richard J. Hodes, MD

Data pooled from both the Chicago Health and Aging Project (CHAP) and the Rush and Memory and Aging Project (MAP) revealed that a combination of at least 4 of the 5 specified health behaviors—physical activity, not smoking, light-to-moderate alcohol consumption, high-quality diet, and cognitive activities—led to a lower risk of Alzheimer disease (AD).^1,2

Funded by the National Institute on Aging (NIA), part of the National Institutes of Health (NIH), the results showed that risk of AD was 60% lower (pooled hazard ratio [HR] 0.40; 95% CI, 0.28—0.56) in those with 4 to 5 health risk factors compared to participants with 0 to 1 healthy lifestyle factors. Additionally, those with 2 to 3 healthy lifestyle factors had a 37% lower risk (pooled HR 0.63; 95% CI, 0.47–0.84) than those with 0 to 1 healthy lifestyle risk factors.

“The findings strengthen the association between healthy behaviors and lower risk and add to the basis for controlled clinical trials to directly test the ability of interventions to slow or prevent development of Alzheimer’s disease,” Richard J. Hodes, MD, director, NIA, said in a statement.

During a median follow-up of 5.8 years in CHAP (n = 1,845) and 6.0 years in MAP (n = 920), 379 and 229 participants, respectively, had incident AD. The pooled HR of AD across 2 cohorts was 0.73 (95% CI, 0.66—0.80) per each additional healthy lifestyle factor using multivariate-adjusted models.

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When using a health score without light to moderate alcohol intake, the HRs of Alzheimer dementia per 1 healthy factor increase in the lifestyle score were 0.71 (95% CI, 0.59—0.86) in CHAP and 0.70 (95% CI, 0.61–0.81) in MAP, similar to the primary analysis. Similar results were found when we used never smoking as a healthy lifestyle factor.

Definition of healthy lifestyle score was on the basis of nonsmoking, ≥150 min per week of moderate/vigorous-intensity physical activity, light to moderate alcohol consumption, high-quality Mediterranean-DASH Diet Intervention for Neurodegenerative Delay Diet (MIND, upper 40%), and engagement in late-life cognitive activities (upper 40%), all between an overall score of 0 to 5.

Researchers used Cox proportional hazard models for each cohort to estimate the HR and 95% CI of the lifestyle score with AD, and a random-effect meta-analysis to pool the results.

Healthy lifestyle factors were also narrowed down in into low- and high-risk categories. Those with ≥150 min per week in moderated or vigorous activities were low risk while those with less than 150 or sedentary activity were higher risk. Cognitive activity in the upper two-fifths, or the highest 40%, of the distribution were low-risk and those in the bottom three-fifths of the distribution were high-risk. Increasing physical activity, along with blood pressure management and cognitive training was “encouraging although inclusive” for preventing AD in a 2017 research review commissioned by the NIA.

A high-quality MIND diet, which combines the Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diet, was also recommended. A study published by the National Eye Institute (NEI) in early April suggested that dietary factors can play a role in slowing cognitive decline. More specifically, diets that include high consumption of vegetables, whole grains, fish, and olive oil correlate with higher cognitive function.³

Research showed that the odds ratio (OR) for cognitive impairment in patients with the greatest adherence to the alternative Mediterranean diet (aMED) was 0.36 (P = .0001) for a Modified Mini-Mental State Examination (3MS) score <80, 0.56 for composite score (P = .001), as well as 0.56 for Telephone Interview Cognitive Status-Modified (TICS-M) score <30 and 0.48 for composite score (P <.0001 for both) compared with those in the lowest adherence tertile.^3,4

Dallas Anderson, PhD, program director, Division of Neuroscience, NIA, said in a statement when discussing the results of the 2 pooed studies, “It’s not a clear cause and effect result, but a strong finding because of the dual data sets and combination of modifiable lifestyle factors that appear to lead to risk reduction.”

REFERENCES

1. Combination of healthy lifestyle traits may substantially reduce Alzheimer’s [news release]. NIH. Published June 17, 2020. Accessed June 22, 2020. nih.gov/news-events/news-releases/combination-healthy-lifestyle-traits-may-substantially-reduce-alzheimers

2. Dhana K, Evans DA, Rajan KB. Healthy lifestyle and the risk of Alzheimer dementia. Neurology. Published online June 17, 2020. doi: 10.1212/WNL.0000000000009816.

3. Diet may help preserve cognitive function [news release]. Bethesda, MD: National Institutes of Health; Published April 14, 2020. Accessed June 22, 2020. nih.gov/news-events/news-releases/diet-may-help-preserve-cognitive-function

4. Keenan, TD, Agron E, Mares JA, et al. Adherence to a Mediterranean diet and cognitive function in the Age-Related Eye Disease Studies 1 & 2. Alzheimers Dement. Published online April 13, 2020. doi: 10.1002/alz.12077