Effects of Walnut Consumption on Cognitive Performance in Young Adults

Br J Nutr. 2012 May;107(9):1393-401. doi: 10.1017/S0007114511004302. Epub 2011 Sep 19.

Abstract

Walnuts contain a number of potentially neuroprotective compounds like vitamin E, folate, melatonin, several antioxidative polyphenols and significant amounts of n-3 α-linolenic fatty acid. The present study sought to determine the effect of walnuts on verbal and non-verbal reasoning, memory and mood. A total of sixty-four college students were randomly assigned to two treatment sequences in a crossover fashion: walnuts-placebo or placebo-walnuts. Baseline data were collected for non-verbal reasoning, verbal reasoning, memory and mood states. Data were collected again after 8 weeks of intervention. After 6 weeks of washout, the intervention groups followed the diets in reverse order. Data were collected once more at the end of the 8-week intervention period. No significant increases were detected for mood, non-verbal reasoning or memory on the walnut-supplemented diet. However, inferential verbal reasoning increased significantly by 11.2 %, indicating a medium effect size (P = 0.009; d = 0.567). In young, healthy, normal adults, walnuts do not appear to improve memory, mood or non-verbal reasoning abilities. However, walnuts may have the ability to increase inferential reasoning.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cognition / physiology*
  • Cross-Over Studies
  • Diet*
  • Double-Blind Method
  • Female
  • Humans
  • Juglans*
  • Male
  • Memory / physiology*
  • Neuroprotective Agents / chemistry
  • Neuropsychological Tests
  • Nuts*
  • Young Adult

Substances

  • Neuroprotective Agents