Submitted to: Journal of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/1/2007
Publication Date: 6/1/2007
Citation: Mills, J.P., Simon, P.W., Tanumihardjo, S.A. 2007. ß-Carotene from Red Carrot Maintains Vitamin A Status, but Lycopene Bioavailability Is Lower Relative to Tomato Paste in Mongolian Gerbils. Journal of Nutrition. 137:1395-1400. Interpretive Summary: Orange carrots are an important source of ß-Carotene and red tomatoes are an important source of lycopene. Both of these pigments provide not only the familiar colors of these vegetables, but they also provide health benefits for consumers. To provide these health benefits, pigments must be bioavailable, that is, able to be taken up by the gut during the digestive process. Red carrots provide both of these pigments and this study evaluated the boavailability of these pigments in gerbils, an animal model with nutrient uptake qualities similar to humans. This research found that both pigments are bioavailable, so the health benefits from both of them can be realized by eating red carrots, but bioavailability of lycopene was reduced when present along with ß-Carotene. This research is of interest to plant scientists studying pigments, to nutritionists, to vegetable growers, and consumers.
Technical Abstract: Red carrots contain lycopene in addition to ß-Carotene. The utility of red carrot as a functional food depends in part on the bioavailability of its constituent carotenoids. Lycopene bioavailability was compared in Mongolian gerbils (Meriones unguiculatus) fed freeze-dried red carrot and tomato paste (Study 1, n = 47) and whole food extracts dissolved in cottonseed oil (Study 2, n = 39). Diets and supplements were equalized for lycopene and intakes were not different. Both studies utilized negative (oil) and positive [purified lycopene (Lyc)] controls. In Study 1, red carrot group vitamin A liver stores (0.68 + 0.13 'mol/liver) were not different from baseline (0.63 + 0.13 'mol/liver) and greater than tomato paste (0.43 + 0.12 'mol/liver), Lyc (0.51 + 0.14 'mol/liver), and control (0.38 + 0.17 'mol/liver) groups (P < 0.003). A similar pattern was observed in Study 2. In both studies, hepatic lycopene was higher in the tomato paste (82.7 + 26.7 and 80.7 + 20.2 nmol/liver) groups compared to red carrot groups (59.3 + 21.9 and 39.5 + 14.1 nmol/liver, P < 0.0001). Hepatic lycopene from tomato paste was higher than Lyc in Study 1, but tomato paste extract and Lyc did not differ in Study 2 when both were dissolved in oil. Red carrot maintains vitamin A status, but constituent ß-Carotene may interfere with lycopene bioavailability. These results confirm prior studies in humans on the relative bioavailability of lycopene from red carrots and tomato paste and expand them by suggesting mechanism and determining vitamin A value.