RESUMEN
OBJECTIVE: This study examined the influence of age, nutrition (as measured through food diaries and serum/plasma biomarkers) and inflammatory markers on cognitive performance in adults 60 years of age and older. DESIGN: A cross-sectional population based study, data from the National Health and Nutrition Examination Survey (NHANES; 2001-2002 wave). PARTICIPANTS: This study included 1,048 adults who had valid dietary data, blood biomarkers, were 60 years or older, completed the cognitive test, and had complete demographic information. METHOD: A series of regression models were used to examine the relationship between cognitive function as measured by the Digit Symbol Substitution Task (DSST), dietary factors/biomarkers and inflammation. Mediation analyses were then utilized to examine whether individual nutrients accounted for the relationships between age and DSST performance. RESULTS: Dietary fat intake, serum vitamin E, serum folate, serum iron, plasma homocysteine, and serum vitamin D were significantly associated with better DSST performance. Elevated fibrinogen and C-reactive protein, were significantly associated with poorer cognitive function, but did not remain statistically significant after controlling for age, gender, education, ethnicity, income, and total calorie intake. Serum vitamin D and plasma homocysteine accounted for a portion of age-related variance in DSST. Specifically, higher levels of vitamin D were related to better DSST performance, while higher homocysteine resulted in poorer cognitive performance. CONCLUSION: Diet and nutrition are important modifiable factors that can influence health outcomes and may be beneficial to remediate age-related declines in cognition. Adequate nutrition may provide a primary preventive approach to healthy aging and maintenance of cognitive functioning in older adults.