Effect of Dietary Intake Through Whole Foods on Cognitive Function: Review of Randomized Controlled Trials

This review evaluated recent randomized controlled trials (RCTs) examining the chronic intake of whole foods associated with the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurogenerative Delay (MIND), and ketogenic (KETO) diets on cognitive function.

We identified RCTs related to olive oil (N = 3), nuts (N = 7), fatty fish (N = 1), lean meats (N = 4), fruits and vegetables (N = 9), legumes (N = 1), and low-fat dairy (N = 4), with 26/29 reporting positive results on at least one measure of cognition. We also identified 6 RCTs related to whole food-induced KETO diets, with half reporting positive effects on cognition. Variations in study design (i.e., generally the studies are < 6 months and include middle-aged and older, cognitively intact participants) and small sample sizes make it difficult to draw conclusions across studies; however, the current evidence from RCTs generally supports individual component intakes of these dietary patterns as an effective, nonpharmacological approach to improve cognitive health in adults.