Long-term intake of nuts in relation to cognitive function in older women

Abstract

Objective: Nuts contain nutrients that may benefit brain health; thus, we examined long-term intake of nuts in relation to cognition in older women.

Design: Population-based prospective cohort study.

Setting: Academic research using data from the Nurses' Health Study.

Participants: Nut intake was assessed in a food-frequency questionnaire beginning in1980, and approximately every four years thereafter. Between 1995-2001, 16,010 women age 70 or older (mean age = 74 years) without a history of stroke were administered 4 repeated telephone-based cognitive interviews over 6 years. Our final sample included 15,467 women who completed an initial cognitive interview and had complete information on nut intake.

Main outcome measures: The Telephone Interview for Cognitive Status (TICS), a global score averaging the results of all tests (TICS, immediate and delayed verbal recall, category fluency, and attention), and a verbal memory score averaging the results of tests of verbal recall.

Results: In multivariable-adjusted linear regression models, higher long-term total nut intake was associated with better average cognitive status for all cognitive outcomes. For the global composite score combining all tests, women consuming at least 5 servings of nuts/week had higher scores than non-consumers (mean difference=0.08 standard units, 95% confidence interval 0.00-0.15; p-trend=0.003). This mean difference of 0.08 is equivalent to the mean difference we find between women 2 years apart in age. Long-term intake of nuts was not associated with rates of cognitive decline.

Conclusions: Higher nut intake may be related to better overall cognition at older ages, and could be an easily-modifiable public health intervention.