β-carotene uptake from processed versus raw vegetables in women

Bioavailability of β-carotene is known to be influenced by several dietary factors and characteristics of the food matrix. Tissue uptake from food sources is relevant to both cancer chemoprevention and the eradication of vitamin A inadequacy in undernourished populations. The purpose of this study was to examine the uptake of β-carotene and its isomers from processed versus raw carotenoid-rich vegetables (carrots, spinach). Eight healthy adult females (ages 17-36) participated in the crossover study, comprised of two 4-week treatment periods, in which they were fed approximately 9277 μg β-carotene per day from either processed or raw sources. The amount of β-carotene provided by the food was determined by HPLC methods. Plasma carotenoids, including their isomeric distributions, were measured at baseline and at the end of each treatment period using HPLC. Total plasma βcarotene increased significantly following the processed vegetable feeding period (P = 0.04), and tended to increase following the raw vegetable feeding period (P = 0.07). Average total plasma β-carotene increased by 102% and 33% following the processed and raw feeding periods, respectively. In selected subjects, cervix tissue uptake of β-carotene was also examined in the processed feeding period and a similar average magnitude of increase was observed. Results from this study indicate that daily consumption of carotenoid-rich vegetables, particularly when processed, results in a nromnt and substantial increase in tissue β-carotene concentration.