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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #365726

Research Project: Nutrition, Brain, and Aging

Location: Jean Mayer Human Nutrition Research Center On Aging

Title: An evidence map of walnut intake and cognitive outcomes

item Shukitt-Hale, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/16/2019
Publication Date: 7/23/2019
Citation: Shukitt Hale, B. 2019. An evidence map of walnut intake and cognitive outcomes. 2019 Health Research Conference.

Interpretive Summary:

Technical Abstract: Age-related deficits in cognition are thought to be due to oxidative damage caused by free-radicals and inflammatory response to this and other cellular damage. Therefore, foods high in antioxidant and anti-inflammatory activity, such as berries and nuts could prevent and even reverse the occurrence of the neurochemical and behavioral changes that occur in aging. Walnuts are rich in polyunsaturated fatty acids (PUFAs) and polyphenols which have been shown to improve neurochemical and behavioral function. Previously, we have shown that walnuts are able to reverse several parameters of brain aging as well as age-related motor and cognitive deficits when fed to rats from 19-21 months of age. If these effects translate to older adults, dietary interventions, such as the inclusion of additional servings of walnuts, present a potential means of delaying or minimizing the negative effects of aging on the brain. Therefore, a recent evidence map study was conducted to quantitatively summarize existing evidence from clinical trials that assessed the impact of walnut consumption on cognition and risks of age-related cognitive decline. Sixty-four eligible publications included 50 clinical trials in 58 publications and 9 observational studies in 6 publications; of these only three trials and four cross-sectional studies included cognitive assessment or incidence of dementia. However, the evidence map identified sufficient evidence for a future systematic review and meta-analysis to investigate the relationship between walnut intake and risk factors of age-related cognitive decline commonly reported among trials. It also identified considerable research gaps and future research needs for studies that include clinical assessment of cognition as the primary outcome.