To examine the association between walnut consumption and measures of cognitive function in the US population.
Nationally representative cross sectional study using 24 hour dietary recalls of intakes to assess walnut and other nut consumption as compared to the group reporting no nut consumption.
1988–1994 and 1999–2002 rounds of the National Health and Nutrition Examination Survey (NHANES).
Representative weighted sample of US adults 20 to 90 years of age. Main Outcome Measure: The Neurobehavioral Evaluation System 2 (NES2), consisting of simple reaction time (SRTT), symbol digit substitution (SDST), the single digit learning (SDLT), Story Recall (SRT) and digit-symbol substitution (DSST) tests.
Adults 20–59 years old reporting walnut consumption of an average of 10.3 g/d required 16.4ms less time to respond on the SRTT, P=0.03, and 0.39s less for the SDST, P=0.01. SDLT scores were also significantly lower by 2.38s (P=0.05). Similar results were obtained when tertiles of walnut consumption were examined in trend analyses. Significantly better outcomes were noted in all cognitive test scores among those with higher walnut consumption (P < 0.01). Among adults 60 years and older, walnut consumers averaged 13.1 g/d, scored 7.1 percentile points higher, P=0.03 on the SRT and 7.3 percentile points higher on the DSST, P=0.05. Here also trend analyses indicate significant improvements in all cognitive test scores (P < 0.01) except for SRTT (P = 0.06) in the fully adjusted models.
These significant, positive associations between walnut consumption and cognitive functions among all adults, regardless of age, gender or ethnicity suggest that daily walnut intake may be a simple beneficial dietary behavior.
Dye L, Lluch A, Blundell JE. Macronutrients and mental performance. Nutrition. 2002;16(10):1021–34.
Rogers PJ. A healthy body, a healthy mind: long-term impact of diet on mood and cognitive function. Proc Nutr Soc. 2001;60(1):135–43.
Zhang J, Hebert JR, Muldoon MF. Dietary fat intake is associated with psychosocial and cognitive functioning of school-aged children in the United States. J Nutr. 2005;135(8):1967–73.
Bailey R, Arab L. Nutritional prevention of cognitive decline. Adv Nutr. 2012;3(5):732–3.
Estruch R, et al. Primary prevention of cardiovascular disease with a Mediterranean diet. N Engl J Med. 2013;368(14):1279–90.
Misirli G, et al. Relation of the traditional Mediterranean diet to cerebrovascular disease in a Mediterranean population. Am J Epidemiol. 2012;176(12):1185–92.
Valls-Pedret C. Polyphenol-rich foods in the Mediterranean diet are associated with better cognitive function in elderly subjects at high cardiovascular risk. J Alzheimer’s Dis, 2012. 29(4):773–82.
Feart C, et al. Adherence to a Mediterranean diet, cognitive decline, and risk of dementia. JAMA. 2009;302(6):638–48.
Scarmeas N, et al. Mediterranean diet and mild cognitive impairment. Arch Neurol. 2009;66(2):216–25.
Scarmeas N, et al. Mediterranean diet and risk for Alzheimer’s disease. Ann Neurol. 2006;59(6):912–21.
Gao X, et al. Prospective study of dietary pattern and risk of Parkinson disease. Am J Clin Nutr. 2007;86(5):1486–94.
Essa MM, et al. Neuroprotective effect of natural products against Alzheimer’s disease. Neurochem Res. 2012;37(9):1829–42.
Chauhan N, et al. Walnut extract inhibits the fibrillization of amyloid beta-protein, and also defibrillizes its preformed fibrils. Curr Alzheimer Res. 2004;1(3):183–8.
Muthaiyah B, et al. Protective effects of walnut extract against amyloid beta peptide-induced cell death and oxidative stress in PC12 cells. Neurochem Res. 2011;36(11): 2096–103.
Krieg EF, Jr., et al. Neurobehavioral test performance in the third National Health and Nutrition Examination Survey. Neurotoxicol Teratol. 2001;23(6):569–89.
Morris MS, Jacques PF, Rosenberg IH, Selhub J. Hyperhomocysteinemia associated with poor recall in the third National Health and Nutrition Survey. Am J Clin Nutr. 2001;73(5): 927–33.
Park KM, Fulgoni VL, 3rd. The association between dairy product consumption and cognitive function in the National Health and Nutrition Examination Survey. Br J Nutr. 2013;109(6):1135–42.
Kuo HK, et al. Cognitive function, habitual gait speed, and late-life disability in the National Health and Nutrition Examination Survey (NHANES) 1999–2002. Gerontology. 2007;53(2): 102–10.
Rosano C, et al. Association between physical and cognitive function in healthy elderly: the health, aging and body composition study. Neuroepidemiology. 2005;24(1–2):8–14.
Dwyer J, Picciano MF, Raiten DJ. Collection of food and dietary supplement intake data: What We Eat in America-NHANES. J Nutr. 2003;133(2):590S–600S.
Dwyer J, Picciano MF, Raiten DJ. Future directions for the integrated CSFII-NHANES: What We Eat in America-NHANES. J Nutr. 2003;133(2):576S–81S.
Kant AK, Graubard BI. Secular trends in patterns of self-reported food consumption of adult Americans: NHANES 1971–1975 to NHANES 1999–2002. Am J Clin Nutr. 2006;84(5):1215–23.
Zhang J, et al. Cognitive performance is associated with macronutrient intake in healthy young and middle-aged adults. Nutr Neurosci, 2006;9(3–4):179–87.
Nooyens AC, et al. 2011 Fruit and vegetable intake and cognitive decline in middle-aged men and women: the Doetinchem Cohort Study. Br J Nutr. 2011;106(5):752–61.
Nurk E, et al. Cognitive performance among the elderly in relation to the intake of plant foods. The Hordaland Health Study. Br J Nutr. 2010;104(8):1190–201.
Pribis P, et al. Effects of walnut consumption on cognitive performance in young adults. Br J Nutr. 2011;107(9):1393–401.
About this article
Cite this article
Arab, L., Ang, A. A cross sectional study of the association between walnut consumption and cognitive function among adult us populations represented in NHANES. J Nutr Health Aging 19, 284–290 (2015). https://doi.org/10.1007/s12603-014-0569-2
- cognitive decline
- cognitive function