Salad and raw vegetable consumption and nutritional status in the adult US population: results from the Third National Health and Nutrition Examination Survey.J Am Diet Assoc 2006; 106(9):1394-404JA
To examine the relationship between reported salad consumption and serum nutrient levels as well as dietary adequacy, as defined by nutrient intakes, in relation to the National Academy of Science Food and Nutrition Board Guidelines, in pre- and postmenopausal women and in men of comparable ages.
Analyses of 24-hour recalls were conducted to determine dietary intake using the Third National Health and Nutrition Examination Survey data. Salad consumption was assessed based on intakes of salad, raw vegetables, and salad dressing.
Nine thousand four hundred-six women and 8,282 men aged 18 to 45 years and older than 55 years were examined between 1988 and 1994.
Regressions were used to model associations between salad and raw vegetable consumption and selected serum nutrient outcomes. Usual nutrient intake distributions were estimated using the Iowa State University method for adjustment of the distribution. The Estimated Average Requirement method was used to determine the proportion of subjects with inadequate intake for each nutrient.
The consumption of salads, raw vegetables, and salad dressing was positively associated with above-median serum micronutrient levels of folic acid, vitamins C and E, lycopene, and alpha- and beta-carotene. Each serving of salad consumed was associated with a 165% higher likelihood to meet the recommended Dietary Allowance for vitamin C in women and 119% greater likelihood in men.
Salad consumers tended to have more favorable intakes of vitamins C and E, folic acid, and carotenoids, after adjustment for other differences. The significant and consistently higher serum values of these vitamins among salad consumers suggest that they are being well absorbed from salad. Salad, salad dressing, and raw vegetable consumption can be an effective strategy for enhancing nutritional adequacy and increasing vegetable consumption in the population at large.