GENDER DIFFERENCES IN PHYTOESTROGEN INTAKE AND SPEED OF PROCESSING PERFORMANCE IN OLDER ADULTS

Abstract

Phytoestrogen consumption mimics estrogen in the body, albeit to a much smaller scale, and therefore represent a potential dietary intervention to supplement estrogen loss or hormonal changes. Additionally, studies have reported that phytoestrogens may benefit cognitive health, although this may differ among males and females in older adults due to differences in absorption, hormones, and age-related changes. In the current study, urinary phytoestrogen concentrations (covariate-adjusted standardized for urinary creatinine) and gender were used as predictors to examine differences in relation to speed of processing (SOP) measured by the Digit Symbol Substitution Test (DSS). Participants were drawn from The National Health and Nutrition Examination Survey (NHANES 1999–2002) and consisted of 354 individuals ranging from 65 to 85 years old. A multiple regression analysis included covariates; age, BMI, race, education, smoking, socioeconomic status, and urinary creatinine. Among the individual phytoestrogens, genistein demonstrated significant gender differences relating to SOP. Females scored higher on the DSS with increased amounts of genistein while demonstrating the opposite for males. Interestingly, for the overall lignan predictor, higher lignans were associated with better SOP performance in males but lower SOP performance in females. Overall, females scored higher on the DSS compared to males regardless of the number of phytoestrogens. Results suggest that there are significant gender differences in both the predictors of genistein and lignan consumption. Both yielded different associations demonstrating the potential impact that specific phytoestrogens may have on cognitive aging depending on gender. To become a viable intervention, further research on these gender differences are needed.