Intestinal absorption of lycopene from different matrices and interactionsto other carotenoids, the lipid status, and the antioxidant capacity of human plasma

Background: The bioavailability of carotenoids has been investigated in ani mal studies as well as in human studies, so far mostly for beta-carotene. o nly few results exist for lycopene. In recent studies, lycopene was signifi cantly better available from processed tomatoes compared to raw tomatoes, w hen using daily intakes between 16.5 mg and 75 mg lycopene. Aim of the study In a comparative study the availability of a low oral lyco pene dosage of 5 mg/d from different food matrices versus soft gel capsules containing tomato oleoresin was assessed. In addition to the plasma carote noid content, the effect of lycopene ingestion on other plasma carotenoids, the lipid status parameters, and the antioxidant activity was estimated. Methods Twenty-two female adults (20 - 27 v) were randomized in three group s and were advized to minimize their carotenoid intake for two weeks. After this initial period, two groups received a portion of tomatoes or tomato j uice adjusted to a lycopene dose of 5 mg/d, the third group ingested the sa me dose comprized in soft gel capsules containing tomato oleoresin. During the test period of 6 weeks, the participants continued reducing the intake of carotenoids from food. Fasting blood samples were withdrawn prior to the study, before supplementation started, and then weekly while supple mented. Seven-day dietary records were pre pared before the study started and after one week of supplementation. Carotenoids were analyzed by reversed phase H PLC with diode array detection. Dietary records were evaluated using the co mputer software EBIS 2.1. The plasma total cholesterol. HDL cholesterol, an d triglycerides were determined enzymatically. In addition. the antioxidant activity of plasma was estimated by using the TEAC and the TRAP assays. Results The basal levels of lycopene in plasma were comparable for all grou ps (0.2 - 0.3 mu mol/l) and decreased significantly during the two weeks of depletion to approximately 50 % of the basal values. Other plasma caroteno ids such as beta-carotene and beta-cryptoxanthin decreased significantly, t oo, whereas lutein and zeaxanthin remained unchanged. After supplementation with tomato oleoresin capsules or tomato juice, the plasma lycopene increa sed significantly, while it remained unchanged during intake of tomatoes. N ormal dietary habits were practized of all volunteers before and during the study except vitamin C whose intake was significantly lower during the stu dy period, because the probands were recommended to reduce the intake of fr uits and vegetables. Lycopene supplementation did not affect the lipid stat us parameters of the three groups. After ingestion of lycopene the antioxid ant activity of the plasma was not altered. Mean TEAC values were estimated to 0.33 +/- 0.05 mmol/l and TRAP values to 1.0 +/- 0.1 mmol/l and showed n o significant differences in all groups during the whole study period. Conclusions The bioavailability of lycopene varied significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tom ato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. The daily intake of 5 mg lycopene, an intake comparable to the usual daily carotenoid intake, did not affect cholesterol and triglycerides in plasma o r its antioxidant capacity.