Association between the consumption of tree nut and peanut and cognitive performance among middle-aged and older adults: Evidence from the Chinese Square Dancer Cohort

Background: The inclusion of nuts in the diet has been explored as a dietary approach for supporting cognition health across the lifespan. However, research on the types of nuts and their effects on various cognitive domains remains limited, especially in Chinese populations.Methods: This cross-sectional study investigated the associations of tree nut and peanut consumption with cognitive function and mild cognitive impairment (MCI) risk among middle-aged and older adults from the Chinese Square Dancer Cohort. Data on nut consumption were collected using a semi-quantitative food frequency questionnaire. Cognitive function was assessed by the neuropsychological tests, such as the Verbal Fluency Test (VFT), Auditory Verbal Learning Test (AVLT), Trail Making Test-B (TMT-B), and the Digit Symbol Substitution Test (DSST), and the diagnosis of MCI was conducted following Petersen’s criteria. Multiple linear and logistic regression models were utilized to examine the relationship between the consumption of tree nut and peanut and cognitive performance, as well as the likelihood of MCI.Results: This study included 4,275 adults aged 55 and above. After controlling demographic characteristics, lifestyle factors, other dietary factors, and history of chronic disease, tree nut consumption was positively associated with global cognition scores (P for trend < 0.001). Compared with non-consumers of tree nuts (0 g/day), the β values (95% confidence intervals, 95% CIs) were 0.10 (0.06, 0.15) for 0.01–4.99 g/day, 0.12 (0.06, 0.18) for 5.00–9.99 g/day, and 0.15 (0.10, 0.20) for ≥10.00 g/day. Participants consuming ≥10.00 g/day of tree nuts also had lower odds of MCI than non-consumers (odds ratio [OR] = 0.69, 95% CI: 0.55, 0.87). As for peanuts, no significant association with MCI was observed after full adjustment. Peanut consumption showed weaker and non-linear associations with global cognition; compared with non-consumers, the β values (95% CIs) were 0.07 (0.03, 0.12) for 0.01–4.99 g/day.Conclusions: Higher tree nut consumption was associated with better overall cognitive performance and lower odds of MCI. Peanut consumption showed weaker and non-linear associations with global cognition, but was not significantly associated with MCI after full adjustment.