FROM:
Eur J Nutr 1999 (Jun); 38 (3): 118–125
Bohm V; Bitsch R
BACKGROUND: The bioavailability of carotenoids
has been investigated in animal studies as well as in human
studies, so far mostly for beta- carotene. Only few results exist
for lycopene. In recent studies, lycopene was significantly
better available from processed tomatoes compared to raw
tomatoes, when 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 lycopene dosage of 5 mg/d from
different food matrices versus soft gel capsules containing
tomato oleoresin was assessed. In addition to the plasma
carotenoid 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 y) were
randomized in three groups and were advised to minimize their
carotenoid intake for two weeks. After this initial period, two
groups received a portion of tomatoes or tomato juice adjusted to
a lycopene dose of 5 mg/d, the third group ingested the same dose
comprised 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samples were withdrawn prior to the study, before supplementation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 supplemented. Seven-day dietary
records were prepared before the study started and after one week
of supplementation. Carotenoids were analyzed by reversed phase
HPLC with diode array detection. Dietary records
were evaluated using the computer software EBIS 2.1. The plasma
total cholesterol, HDL cholesterol, and 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 groups (0.2-0.3 mumol/l) and decreased
significantly during the two weeks of depletion to approximately
50% of the basal values. Other plasma carotenoids such as beta-
carotene and beta-cryptoxanthin decreased significantly, too,
whereas lutein and zeaxanthin remained unchanged. After
supplementation with tomato oleoresin capsules or tomato juice,
the plasma lycopene increased significantly, while it remained
unchanged during intake of tomatoes. Normal dietary habits were
practised of all volunteers before and during the study except
vitamin C whose intake was significantly lower during the study
period, because the probands were recommended to reduce the
intake of fruits and vegetables.
Lycopene supplementation did not affect the lipid status
parameters of the three groups. After ingestion of lycopene the
antioxidant 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 no 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 tomato 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 or its antioxidant
capacity.