Assessing the Relationship Between Nutrition Knowledge and Skin Carotenoids in University Students

To determine whether nutrition knowledge is associated with skin carotenoids, as measured by reflection spectroscopy, a valid and objective assessment of fruit and vegetable intake. A convenience sample of undergraduate and graduate students were recruited through flyers, classroom announcements, and email distribution lists at a large public university in California. Nutrition knowledge was assessed with a validated questionnaire. Skin carotenoids were measured with reflection spectroscopy (RS) using a device known as the Veggie MeterTM. Participants completed the nutrition knowledge questionnaire and height, weight, and RS data were collected by trained researchers at a single time-point. Data were collected as part of a larger, on-going study. Pearson’s correlation and ordinary least-squares (OLS) regression analysis were used to determine the relationship between nutrition knowledge and skin carotenoids. A total of 40 students participated in the study; 72% were female. Nutrition knowledge scores ranged from 13 to 53 with a mean of 37.95 (out of 58 possible), and the mean RS score was 334.0. Skin carotenoids were found to be significantly correlated with nutrition knowledge (r = 0.332; P = 0.036), with 8.7% of variance in RS score explained by nutrition knowledge. Body mass index (BMI) was found to be negatively associated with RS score at P < 0.05; when BMI was incorporated, the proportion of variance in RS score explained by the regression model was 26.9%. Gender was not found to significantly associated with RS score (P = 0.965). These preliminary data suggest that nutrition knowledge may be a significant predictor of dietary fruit and vegetable intake when accounting for BMI in university students. Future studies will incorporate additional variables, such as food security status and diet quality to further elaborate on the relationship between nutrition knowledge and behavior. This project was funded by an internal University of California, Davis grant.