A recent study published in The American Journal of Clinical Nutrition investigates the associations between nut consumption and changes in cognitive performance.

Study: Higher versus lower nut consumption and changes in cognitive performance over two years in a population susceptible to cognitive decline: a cohort study. Image Credit: CreatoraLab / Shutterstock.com

Are nuts good for brain health?

Weight loss plan is taken into account a serious modifiable lifestyle factor and plays an important role in regulating other risk aspects for certain health conditions.

Peanuts and tree nuts are enriched with nutrients and have anti-inflammatory and antioxidant properties. The truth is, the assorted nutrients and lively compounds present in nuts also can elicit neuroprotective effects. Nevertheless, there is restricted epidemiologic evidence for the associations between nut intake and cognitive performance.

While many cross-sectional studies support that cognitive function and nut consumption are positively related, prospective studies and randomized controlled trials (RCTs) have reported mixed results. Thus, existing evidence of the impact of nut intake on cognitive performance stays inconclusive.

Concerning the study

In the current study, researchers prospectively assess the associations between the consumption of nuts and two-year changes in cognitive performance in a Spanish cohort of older adults susceptible to cognitive decline. Obese or obese community-dwelling individuals between 55 and 75 years of age with metabolic syndrome at baseline were eligible for inclusion.

Participants accomplished a food-frequency questionnaire that assessed the habitual intake of various food items up to now 12 months. Nut consumption was stratified as lower than one serving each week, one to 2 servings each week, three to 6 servings each week, and 7 or more servings each week. Trained personnel assessed cognitive performance at baseline and after two years.

Eight neuropsychological tests were administered during personal interviews. Cognitive tests were standardized to a z-score for every participant using mean and standard deviation of baseline data.

The difference between scores was estimated to explore cognitive performance changes. Composite measures for a world assessment of cognitive function and three cognitive domains, including general cognition, executive function, and a focus, were calculated.

The first end result was the two-year changes within the composite scores. Data on sociodemographics, lifestyle, food consumption, medical history, and anthropometrics were obtained at baseline.

Depressive symptoms were assessed using the Beck Depression Inventory. The associations of nut consumption with two-year cognitive function changes were examined using multivariable linear regression models.

Study findings

The study included 6,630 participants with a mean of 65, with females representing 48.4% of the study cohort. The each day average nut consumption was 1.7 g and 43.7 g in the bottom and highest consumption categories at baseline, respectively, with walnuts being essentially the most consumed. Individuals with the best consumption had higher education, higher Mediterranean food plan adherence, and better physical activity than those with the bottom intake.

Moreover, there have been fewer current smokers and depressive individuals in the best consumption category. Participants with the best intake also had a lower waist circumference and body mass index (BMI) than those with the bottom intake.

A positive association between nut consumption and two-year cognitive performance changes was observed. In multivariable models, a one-serving of nuts each day was related to more favorable changes in the final cognitive function and clock drawing test (CDT).

Participants consuming three to 6 servings of nuts every week had higher evolution of cognitive performance at two years than those consuming lower than one serving each week. This finding was not observed for the best category of nut consumption. The associations between nut intake and two-year cognitive changes were similar in sensitivity analyses.

The researchers didn’t observe significant interactions of nut intake with education level, sex, smoking status, hypertension, hypercholesterolemia, or type 2 diabetes. The stratified evaluation revealed an association between more frequent nut consumption and fewer cognitive decline only in those with depressive symptoms at baseline. 

Conclusions

In the present study, higher nut consumption was related to more favorable changes in CDT and general cognitive function, thus indicating a possible dose-response association. Synergistic interactions between depression and nut intake were also observed, which means that individuals with depressive symptoms at baseline were prone to profit more from nut consumption.

Taken together, higher nut consumption might delay cognitive decline over two years in older, obese, or obese adults with metabolic syndrome. Nevertheless, additional epidemiologic and clinical studies are needed to corroborate these findings before dietary recommendations might be made for delaying or stopping dementia and cognitive impairment.