Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 5, 1999
Publication Date: N/A
Interpretive Summary: Epidemiologic studies associate the ingestion of lycopene-rich foods, such as tomatoes and tomato products, with reduced risk for certain degenerative diseases. If lycopene is in fact, the beneficial constituent of tomatoes, it needs to be absorbed by the intestine and transported via the circulation to the various tissues where it may exert its effect. The objective of this study was to monitor changes of lycopene content in buccal mucosa cells (from the inside of the cheeks) and in plasma following daily intake of tomato juice and two lycopene supplements for four weeks. Fifteen subjects completed the study. Lycopene in buccal cells increased about two-fold following the supplement treatment and 25 percent upon tomato juice ingestion. In plasma, lycopene increased more slowly during the tomato juice treatment compared with the two supplements, which may explain the smaller increase of lycopene in buccal cells. It is possible that prolonged intake of tomato juice will yield comparable cellular levels of lycopene as those produced by the supplements. Other tomato carotenoids were also increased in buccal cells following the treatments. In light of the potential health benefit of tomato products, the finding that lycopene and other tomato-related carotenoids are reaching the cells for possible utilization is important. These findings will be valuable for other health professionals, dietitians, and policy makers concerned with improving health throughout the world.
Technical Abstract: We studied the appearance of lycopene in buccal mucosa cells (BMC) after daily ingestion of tomato juice and two dietary supplements, each containing 70-75 mg lycopene, in 15 healthy volunteers. Subjects ingested lycopene-rich tomato juice, tomato oleoresin, lycopene beadlets, and a placebo for four weeks each in a randomized cross-over design while consuming self-selected diets. A 6-wk washout period separated the treatment periods. BMC were collected at baseline and after four weeks of supplementation. Lycopene in BMC increased significantly approximately 2- fold after four weeks of oleoresin and beadlet ingestion to 4.95 mcg/g protein (P < 0.001) and 3.75 mcg/g protein (P = 0.053), respectively, but was not significantly affected by tomato juice treatment. The placebo treatment produced a significant decrease in BMC lycopene levels (P = 0.018). We observed significant treatment differences between oleoresin and tomato juice, oleoresin and placebo, and beadlets and placebo. BMC concentrations of phytofluene and beta-carotene, which were present in small amounts in the lycopene-containing treatments, increased significantly upon ingestion of these treatments. Strong correlations were found between plasma concentrations and levels in BMC for lutein, beta- cryptoxanthin, alpha-carotene, beta-carotene, and phytofluene. Significant correlation between lycopene in plasma and in BMC was observed with oleoresin and placebo treatments, but not with tomato juice or beadlets. We conclude that cellular content of lycopene and other tomato related carotenoids with potential beneficial health effects can be increased through prolonged supplementation. Buccal cell content of carotenoids can serve as an indicator for carotenoid status of the individual.