HEALTH NEWS

Study Title:

Walnuts Boost Cognitive Function

Study 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.

From press release:

Berrien Springs, Mich.—True or False: Walnuts can improve the odds of correctly answering a true or false question. The answer is true according to newly published research in the British Journal of Nutrition (http://journals.cambridge.org/walnuts). The study conducted by researchers at Andrews University in Berrien Springs, Mich., found that walnuts—already known for being a power food—can help increase inferential reasoning, specifically, the ability to discover true from false.

Peter Pribis, associate professor of nutrition and wellness, led the study, “Effects of Walnut Consumption on Cognitive Performance in Young Adults.” Pribis, along with a team of student researchers, tested whether a short, intensive supplementation of a diet with walnuts can have an effect on memory, intuition, mood and critical thinking skills in young adults. In short—would a walnut diet improve cognitive functions?

“We discovered that students who consumed walnuts experienced improvement in critical thinking, specifically inferential reasoning,” says Pribis.

Using two test groups of Andrews University students, each group ate two slices of banana bread daily for eight weeks: one group ate banana bread with ground walnuts and the other group ate banana bread without walnuts present. Each student was tested for inferential reasoning by reading a short narrative followed by five statements. Students then decided whether the statements were true, partially true, false, partially false or there was not enough information to make a judgment.

“Students consuming walnuts showed a significant improvement in inference after consuming one-half cup of walnuts daily for eight weeks,” says Pribis. “Walnuts will obviously not make you a critical thinker; this comes after years of studying. However, students and young professionals in fields that involve a great deal of critical thinking or decision-making could benefit from regularly eating walnuts.” Pribis concludes further research should be done to gain a deeper understanding about the impact of walnuts on cognition. The study was funded by a grant from the California Walnut Commission. The Commission did not have any input on the study design or findings.

Study Information

Pribis P, Bailey RN, Russell AA, Kilsby MA, Hernandez M, Craig WJ, Grajales T, Shavlik DJ, Sabatè J.
Effects of walnut consumption on cognitive performance in young adults.
British Journal of Nutrition
2011 September
Department of Nutrition and Wellness, Andrews University, 8475 University Boulevard, Marsh Hall 313, Berrien Springs, MI 49104-0210, USA.