Interaction between ω-6 fatty acids intake and blood cadmium on the risk of low cognitive performance in older adults from National Health and Nutrition Examination Survey (NHANES) 2011–2014

Abstract Background Identifying preventable diets and environmental exposure is essential to ensuring the health of the aging population. This study evaluated the interaction effect between blood cadmium and ω-6 fatty acids intake on low cognitive performance in Americans. Method The data of this cross-sectional study were obtained from the 2011–2012 and 2013–2014 National Health and Nutritional Examination Survey (NHANES). Cognitive performance was measured by the Consortium to Establish a Registry for Alzheimer’s Disease test, Animal Fluency Test, and Digit Symbol Substitution Test. Multivariate logistic regression models were used. Results A total of 1,918 individuals were included, with 467 (24.35%) low cognitive performance. Compared with participants with normal-level blood cadmium, those with high-level blood cadmium had a higher risk of low cognitive performance [odds ratio (OR) was 1.558 with 95% confidence interval (CI): 1.144–2.123]. Low-level ω-6 fatty acids intake was positively associated with low cognitive performance [OR = 1.633 (95%CI: 1.094–2.436)] compared with normal-level intake. Moreover, there was a significant interaction between low-level ω-6 fatty acids intake and high-level blood cadmium on the risk of low cognitive performance (relative excess risk due to interaction: 0.570, 95%CI: 0.208-0.932; the attributable proportion of interaction: 0.219, 95%CI: 0.102‐0.336; synergy index: 1.552, 95%CI: 1.189‐2.027). Conclusions There was a synergistic interaction between low-level ω-6 fatty acids intake and high-level blood cadmium on low cognitive performance. Low-level ω-6 fatty acids intake may amplify the adverse effects of long-term exposure to cadmium on cognitive performance. This may have a certain significance for the prevention of cognitive decline in the elderly.