Dietary patterns in middle age: effects on concurrent neurocognition and risk of age-related cognitive decline

Abstract

Context: Diet plays a critical role in cognitive integrity and decline in older adults. However, little is known about the relationship between diet and cognitive integrity in middle age.

Objective: To investigate the relationship between dietary patterns in healthy middle-aged adults and neurocognition both in middle age and later in life.

Data sources: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, the following electronic databases were searched: Web of Science, Scopus, PubMed, and PsychInfo.

Data extraction: Data from eligible articles was extracted by 2 reviewers.

Data analysis: Articles included in the systematic review were synthesized (based on the synthesis without meta-analysis reporting guidelines) and assessed for quality (using the Joanna Briggs Institute checklist for randomized controlled trials, cohort studies, and cross-sectional studies) by 2 reviewers.

Results: Of 1558 studies identified, 34 met the eligibility criteria for inclusion. These comprised 9 cross-sectional studies, 23 longitudinal or prospective cohort studies, and 2 randomized controlled trials. Findings were mixed, with some studies reporting a significant positive relationship between adherence to various "healthy" dietary patterns and neurocognition, but others reporting no such relationship.

Conclusion: This systematic review demonstrated that adherence to the Mediterranean diet and other healthy dietary patterns in middle age can protect neurocognition later in life.

Systematic review registration: PROSPERO registration no. CRD42020153179.

Keywords: Alzheimer’s disease; DASH diet; MIND diet; Mediterranean diet; cognition; cognitive impairment; cognitive performance; dementia; dietary pattern; healthy diet; mild cognitive impairment.