Scientific Study

Background: Tree nuts and peanuts (henceforth, nuts) are nutrient-dense foods rich in neuroprotective components; thus, their consumption could benefit cognitive health. However, evidence to date is limited and inconsistent regarding the potential benefits of nuts for cognitive function. Objective: To prospectively evaluate the association between nut consumption and 2-year changes in cognitive performance in older adults at cognitive decline risk. Methods: 6,630 participants aged 55-75 years (mean age 65.0±4.9 years, 48.4% women) with overweight/obesity and metabolic syndrome, completed a validated semi-quantitative food frequency questionnaire and a comprehensive battery of neuropsychological tests at baseline and after a 2-year follow-up. Composite cognitive scores were used to assess global, general, attention, and executive function domains. Nut consumption was categorized as <1, ≥1 to <3, ≥3 to <7, and ≥7 servings/week (1 serving=30 g). Multivariable-adjusted linear regression models were fitted to assess associations between baseline nut consumption and 2-year cognitive changes. Results: Nut consumption was positively associated with 2-year changes in general cognitive function (p-trend <0.001). Compared to participants consuming <1 serving/week of nuts, those categorized as consuming ≥3 to <7 and ≥7 servings/week showed more favorable changes in general cognitive performance (β z-score [95% CI]= 0.06 [0.00,0.12] and 0.13 [0.06,0.20], respectively). No significant changes were observed in the multivariable-adjusted models for other cognitive domains assessed. Conclusion: Frequent nut consumption was associated with smaller decline in general cognitive performance over a 2-year period in older adults at risk of cognitive decline. Randomized clinical trials to verify our findings are warranted. https://doi.org/10.1016/j.ajcnut.2023.05.032