BACKGROUND AND PURPOSE:

• It is unclear if midlife healthy dietary patterns may protect against dementia and mild cognitive impairment
• Dearborn-Tomazos et al. (JAMA Network Open, 2019) investigated a US population without dementia to determine whether there is an association between dietary patterns in midlife with cognitive function in later life

METHODS:

• Observational cohort study
• Study population
  • Community-dwelling individuals participating in the Atherosclerosis Risk in Communities (ARIC) study (began in 1987 and study is ongoing)
  • Randomly selected and recruited | 45 to 64 years of age
• Exposures
  • Western (unhealthy) dietary pattern
    • Higher consumption of meats, fried foods and processed grains
  • Prudent (healthier) dietary pattern
    • Higher in fruits and vegetables, fish, chicken, whole grains etc.
• Study design
  • Participants were assigned into the exposure groups based on food questionnaire
  • Cognitive assessment based on validated cognitive tests
  • Dementia based on in-person assessments, telephone interviews or hospital discharge codes and death certificates
  • Models were generated that adjusted for confounders such as age, education, CVD, alcohol use etc.
• Primary outcomes (changes over 20 years)
  • Estimated 20 year change in cognitive function
  • Relative Risk of incident Dementia

RESULTS:

• 13,588 total participants
  • 7588 (55.8%) women | Mean age of 54.6 years at baseline
• Cognitive scores at baseline were
  • Lower in participants with a Western diet
  • Higher in participants with a prudent diet
  • Differences related to cigarette smoking, eating excess calories, or engaging in less physical activity
• Estimated 20-year change in global cognitive function did not differ by dietary pattern when adjusted for confounders
• The risk of incident dementia did not differ by dietary pattern when adjusted for confounders (p for trend = 0.34)
  • Hazard ratios (HR) vs healthiest diet pattern score (Tertile 1)
    • Tertile 2: HR 0.97 (95% CI, 0.87 to 1.07)
    • Tertile 3: HR 0.99 (95% CI, 0.88 to 1.12)

CONCLUSION:

• The authors acknowledge that while long-term follow-up is a strength of this study, they could not account for all the changes that may occur related to dietary intake and food supply over 20 years
• The results of this study suggest that eating a Western (unhealthy) diet in midlife, compared to a more prudent (healthier) diet, is not associated with cognitive decline nor dementia in later life
• No significant differences in processing speed, word fluency, memory, or incident dementia were identified
• A multimodal approach to reduce cognitive aging may be more beneficial than focusing on diet alone

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Learn More – Primary Sources:

Association of Dietary Patterns in Midlife and Cognitive Function in Later Life in US Adults Without Dementia

Related ObG Topics:

Does a Healthy Lifestyle Decrease Risk of Dementia Even in Those with High Genetic Risk?

Does Fish Consumption Reduce Risk of Dementia?

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