Uptake of lycopene and its geometrical isomers is greater from heat-processed than from unprocessed tomato juice in humans.

Lycopene and beta-carotene are the most abundant carotenoids in human blood and tissues. Although lacking provitamin A activity, lycopene may be biologically active by contributing to the antioxidative defense system of the organism. We studied the uptake of lycopene from processed (boiled with 1% corn oil for 1 h) and unprocessed tomato juice in humans. Lycopene concentrations in human serum increased only when processed tomato juice was consumed. Lycopene uptake varied with individuals, but peak serum concentrations were always reached between 24 and 48 h. The carotenoid was eliminated from serum with a half-life of 2-3 d. The increase in peak serum concentrations was dose-dependent but not linear with the dose. Repeated doses led to a continual rise of lycopene in human serum. Of the different geometrical isomers (all-trans, 9-cis and 13-cis), the cis isomers seemed to be somewhat better absorbed than the all-trans form.     

Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema

Carotenoids are useful oral sun protectants, and supplementation with high doses of beta-carotene protects against UV-induced erythema formation. We compared the erythema-protective effect of beta-carotene (24 mg/d from an algal source) to that of 24 mg/d of a carotenoid mix consisting of the three main dietary carotenoids, beta-carotene, lutein and lycopene (8 mg/d each). In a placebo-controlled, parallel study design, volunteers with skin type II (n = 12 in each group) received beta-carotene, the carotenoid mix or placebo for 12 wk. Carotenoid levels in serum and skin (palm of the hand), as well as erythema intensity before and 24 h after irradiation with a solar light simulator were measured at baseline and after 6 and 12 wk of treatment. Serum beta-carotene concentration increased three- to fourfold (P < 0.001) in the beta-carotene group, whereas in the mixed carotenoid group, the serum concentration of each of the three carotenoids increased one- to threefold (P < 0.001). No changes occurred in the control group. The intake of either beta-carotene or a mixture of carotenoids similarly increased total carotenoids in skin from wk 0 to wk 12. No changes in total carotenoids in skin occurred in the control group. The intensity of erythema 24 h after irradiation was diminished in both groups that received carotenoids and was significantly lower than baseline after 12 wk of supplementation. Long-term supplementation for 12 wk with 24 mg/d of a carotenoid mix supplying similar amounts of beta-carotene, lutein and lycopene ameliorates UV-induced erythema in humans; the effect is comparable to daily treatment with 24 mg of beta-carotene alone.     

Carotenoid and tocopherol composition of human adipose tissue

Concentrations of individual carotenoids and tocopherols were determined in abdominal adipose tissue from 19 adults undergoing corrective surgery. Samples were extracted and saponified before separation and quantitation of carotenoids and tocopherols by reverse-phase high-performance liquid chromatography. Total carotenoid concentration varied 40-fold between individuals, from 0.34 to 13.51 micrograms/g adipose tissue. Beta-carotene and lycopene were the predominant carotenoids, averaging 20.2 and 18.5% of total carotenoids, respectively. In 10 of 19 subjects, the lycopene concentration exceeded that of beta-carotene. Total tocopherol concentrations varied 11-fold, with alpha-tocopherol representing 80.6 +/- 8.1% of the total. Absolute concentrations of both carotenoids and tocopherols were more variable than their relative concentrations. Both beta-carotene and lycopene concentrations were highly correlated with total carotenoid content but there was no correlation between beta-carotene and lycopene or between beta-carotene and alpha-tocopherol concentrations.     

Carotenoids in human buccal mucosa cells after 4 wk of supplementation with tomato juice or lycopene supplements.

BACKGROUND: Lycopene has been identified as a phytochemical with potentially protective health benefits. OBJECTIVE: Our objective was to monitor lycopene changes in buccal mucosa cells (BMCs) in response to 3 vehicles for oral delivery of lycopene. DESIGN: Fifteen healthy subjects ingested lycopene-rich tomato juice, tomato oleoresin, lycopene beadlets (each containing 70-75 mg lycopene) and a placebo for 4 wk each in a randomized crossover design while consuming self-selected diets. A 6-wk washout period separated the treatment periods. BMCs were collected at baseline and after 4 wk of supplementation. RESULTS: Lycopene in BMCs increased significantly ( approximately 2-fold) after 4 wk of ingestion of oleoresin and of beadlets to 4.95 (P < 0.001) and 3.75 microg/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 concentrations (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 with ingestion of these products. Strong correlations were found between plasma and BMC concentrations of lutein, beta-cryptoxanthin, alpha-carotene, and beta-carotene. In contrast, correlations between lycopene concentrations in plasma and in BMCs were weak and not significant for any treatment. CONCLUSIONS: The cellular content of lycopene and other tomato-related carotenoids with proposed beneficial health effects can be increased through prolonged supplementation.     

Changes in serum retinol,alpha-tocopherol,vitamin C,carotenoids, xinc and selenium after micronutrient supplementation during alcohol rehabilitation

OBJECTIVE: To test the effect of a 21-day supplementation with moderate doses of antioxidant nutrients on biochemical indicators of vitamin, carotenoid and trace element levels in alcohol-dependent patients during a program of alcohol rehabilitation. DESIGN: A randomized double-blind trial was performed comparing two groups receiving daily either a combination of micronutrients (beta-carotene: 6 mg, vitamin C: 120 mg, vitamin E: 30 mg, zinc: 20 mg, selenium: 100 micro g) or a placebo. SUBJECTS: 106 alcohol-dependent patients 20 to 60 years of age without severe liver disease, hospitalized for a 21-day rehabilitation program. Measure of Outcome: Vitamin C, retinol, alpha-tocopherol, zeaxanthin/lutein, beta-cryptoxanthin, lycopene, alpha- and beta-carotene, zinc and selenium were measured in serum, initially and after supplementation. RESULTS: (1) In the placebo group, after 21 days of rehabilitation, serum concentrations of vitamin C and all five carotenoids significantly increased, whereas retinol and alpha-tocopherol concentrations decreased; zinc and selenium levels were unaffected. (2) At the end of the hospital stay, serum indicators were significantly improved in the supplement group as compared to the placebo group for vitamin C, alpha-tocopherol, beta-carotene, zinc and selenium; conversely, lycopene changes were higher in the placebo group than in supplement group. (3) Of the serum antioxidants measured at entrance, only vitamin C was significantly depleted in heavy smokers, and, after the supplementation period, vitamin C was efficiently repleted in this later group. CONCLUSION: Our results indicate that a short-term supplementation with physiological doses of antioxidant vitamins, carotenoids and trace elements during alcohol rehabilitation clearly improves micronutrient status indicators. Heavy smokers in particular seem to respond to vitamin C supplementation.     

Circulating levels of retinol, tocopherol and carotenoid in Nepali pregnant and postpartum women following long-term beta-carotene and vitamin A supplementation

OBJECTIVE: To characterize circulating carotenoid and tocopherol levels in Nepali women during pregnancy and post-partum and to determine the effects of beta-carotene and vitamin A supplementation on their concentration in serum. DESIGN: Randomized community supplementation trial. SETTING: The study was carried out from 1994 to 1997 in the Southern, rural plains District of Sarlahi, Nepal. SUBJECTS: A total of 1431 married women had an ascertained pregnancy, of whom 1186 (83%) provided an analyzable serum sample during pregnancy; 1098 (77%) provided an analyzable 3-4 months post-partum serum sample. INTERVENTIONS: Women received a weekly dose of vitamin A (7000 microg RE), beta-carotene (42 mg) or placebo before, during and after pregnancy. Serum was analyzed for retinol, alpha-tocopherol, gamma-tocopherol, beta-carotene, alpha-carotene, lycopene, lutein + zeaxanthin, and beta-cryptoxanthin concentrations during mid-pregnancy and at approximately 3 months post-partum. RESULTS: Compared to placebo, serum retinol, beta-carotene, gamma-tocopherol, beta-cryptoxanthin and lutein + zeaxanthin concentrations were higher among beta-carotene recipients during pregnancy and, except for beta-cryptoxanthin, at postpartum. In the vitamin A group, serum retinol and beta-cryptoxanthin were higher during pregnancy, and retinol and gamma-tocopherol higher at postpartum. Lutein + zeaxanthin was the dominant carotenoid, regardless of treatment group, followed by serum beta-carotene. Serum lycopene level was lowest, and very low compared to the US population. Serum retinol was higher, and carotenoid and alpha-tocopherol lower, at postpartum than during pregnancy in all groups. CONCLUSIONS: Pregnant and lactating Nepali women have lower serum carotenoid and tocopherol levels than well-nourished populations. beta-carotene supplementation appeared to increase levels of tocopherol and other carotenoids in this population.     

Plasma carotenoid response to chronic intake of selected foods and beta-carotene supplements in men.

We determined serial changes in four major plasma carotenoid fractions (alpha-carotene, beta-carotene, lutein/zeaxanthin, and lycopene) in 30 men consuming defined daily doses of carotenoids from foods (broccoli, carrots, or tomato juice) or from purified beta-carotene in capsules (12 or 30 mg) for 6 wk while fed a controlled diet. Compared with baseline, beta-carotene increased in the 30- and 12-mg-capsule and carrot groups whereas alpha-carotene increased in the carrot group and lutein increased in the broccoli group. Lower lutein concentrations in recipients of beta-carotene capsules suggested an interaction between these two carotenoids. Lycopene declined in all groups except the tomato-juice group. Total carotenoid concentration changes only reflected the large increases in beta-carotene concentrations and not the smaller changes observed in other individual carotenoids. Overall, purified beta-carotene produced a greater plasma response than did similar quantities of carotenoids from foods sources. However, some foods increased plasma concentrations of certain carotenoids.     

Loss of carotene-9',10'-monooxygenase expression increases serum and tissue lycopene concentrations in lycopene-fed mice

Two enzymes have been identified for the oxidative metabolism of carotenoids in mammals. Carotene-15,15'-monooxygenase (CMO-I) primarily centrally cleaves β,β-carotene to form vitamin A. We hypothesize that carotene-9',10'-monooxygenase (CMO-II) plays a key role in metabolism of acyclic nonprovitamin A carotenoids such as lycopene. We investigated carotenoid bioaccumulation in young adult, male, wild-type (WT) mice or mice lacking CMO-II (CMO-II KO). Mice were fed an AIN-93G diet or identical diets supplemented with 10% tomato powder, 130 mg lycopene/kg diet (10% lycopene beadlets), or placebo beadlets for 4 or 30 d. Lycopene preferentially accumulated in CMO-II KO mouse tissues and serum compared with WT mouse tissues. β-Carotene preferentially accumulated in some CMO-II KO mouse tissues compared with WT mouse tissues. Relative tissue mRNA expression of CMO-I and CMO-II was differentially expressed in mouse tissues, and CMO-II, but not CMO-I, was expressed in mouse prostate. In conclusion, the loss of CMO-II expression leads to increased serum and tissue concentrations of lycopene in tomato-fed mice.     

Carotenoids in human blood and tissues

The occurrence of carotenoid pigments in human blood and tissues has recently become an area of renewed interest due to the observed inverse relationship between consumption of carotenoid-rich fruits and vegetables and risk of certain cancers. This article reviews current knowledge of the kinds and concentrations of carotenoids in human plasma (or serum) and solid tissues. Most reports have focused on the hydrocarbon carotenoids (lycopene, alpha-carotene, and beta-carotene) with fewer dealing with the more polar xanthophyll pigments. The available literature indicates substantial interindividual heterogeneity with respect to blood levels of both total and individual carotenoids. Reports of solid tissue levels are few, but also indicate large variation, with adipose tissue and liver seemingly the major sites of deposition. The relationship between the types and concentrations of circulating carotenoids and those in solid tissues of the same individuals is not known, but preliminary investigations in our laboratory show considerable qualitative homology between the carotenoids in fasting serum and those in fatty tissue.     

Lipoprotein carotenoid profiles and the susceptibility of low density lipoprotein to oxidative modification in healthy elderly volunteers

OBJECTIVES: To determine antioxidant levels in plasma, low density lipoprotein (LDL) and high density lipoprotein (HDL) before and after supplementation with a carotene mixture or lycopene; to examine the interrelationships between carotenoids and tocopherols in plasma, LDL and HDL under normal dietary conditions and after supplementation with carotene or lycopene; and to investigate whether supplementation with a carotene mixture or lycopene could enhance the ability of LDL to withstand oxidative stress in vitro, in a group of healthy elderly people aged > or =65 y. DESIGN: Randomized placebo controlled double blind study. SETTING: Free living urban adults in Ireland. Subjects: Fifty-one volunteers aged > or =65 y. INTERVENTIONS: Volunteers were each provided with capsules providing either 13.3 mg lycopene, or 11.9 mg carotene or placebo for 12 weeks. RESULTS: Both absolute and cholesterol standardized plasma carotenoid concentrations correlated strongly with LDL and HDL concentrations of carotenoids before and after supplementation with carotene or lycopene. Supplementation with a carotene mixture or lycopene had no effect on oxidative modification of LDL in vitro despite significant increases in plasma and LDL concentrations of lycopene, alpha-carotene and beta-carotene. CONCLUSIONS: The results of this study suggest that, in unsupplemented individuals, plasma can act as a biomarker of carotenoid and gamma-tocopherol concentrations in both LDL and HDL. Supplementation with carotenes or lycopene do not reduce or delay oxidation of LDL. These results support the assumption that carotenoids, such as beta-carotene and lycopene, may show protective effects because they are good markers of fruit and vegetable intake.     

Longitudinal associations between body mass index and serum carotenoids: the CARDIA study

Cross-sectional studies report an inverse association between BMI and serum carotenoid concentration. The present study examined the prospective association between BMI and the serum concentration of five carotenoids in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Serum carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, zeaxanthin/lutein, lycopene), BMI, dietary intake, physical activity and dietary supplement use were measured at years 0 and 7 in 3071 black and white male and female participants, who were either persistent smokers or non-smokers. Among non-smokers, year 0 BMI predicted year 7 serum carotenoid levels: obese subjects (BMI > or =30 kg/m2) had an average concentration of the sum of four carotenoids (alpha-carotene +beta-carotene + zeaxanthin/lutein+beta-cryptoxanthin) that was 22 % lower than the concentration among subjects with a BMI of less than 22 kg/m2. In contrast, the sum of carotenoids among smokers was only 6 % lower. Relationships between BMI and serum lycopene were weak. The change from year 0 to year 7 in serum carotenoids, except for lycopene, was inversely associated with the change in BMI among non-smokers but not among smokers. Parallel findings were observed for BMI and serum gamma-glutamyl transferase level. In summary, the observation that BMI predicted the evolution of serum carotenoids during a 7-year follow-up among young non-smoking adults is consistent with the hypothesis that carotenoids are decreased in protecting against oxidative stress generated by adipose tissue, while smokers maintain a minimal level of serum carotenoids independent of adiposity. The results for lycopene were, however, discordant from those of the other carotenoids.     

In vitro micellarization and intestinal cell uptake of cis isomers of lycopene exceed those of all-trans lycopene

The ratio of cis and all-trans lycopene (LYC) in human and animal tissues exceeds that in foods. The basis for this difference remains unknown, although differences in their stability, transport, and metabolism have been suggested. Here, we systematically compared the digestive stability, efficiency of micellarization, and uptake and intracellular stability of cis and all-trans isomers of LYC and carotenes using the coupled in vitro digestion and Caco-2 human intestinal cell model. Aril and oil from the carotenoid-rich gac fruit (Momordica cochinchinensis Spreng) were cooked with rice to provide a natural source of LYC and carotenes. The ratio of cis:trans isomers of LYC and beta-carotene was similar before and after simulated gastric and small intestinal digestion with recovery of total carotenoids in the digesta exceeding 70%. Micellarization of cis isomers of LYC during digestion of meals with both gac aril and oil was significantly greater than that of the all-trans isomer but less than for the carotenes. Uptake of cis isomers of LYC by Caco-2 cells was similar to that of carotenes and significantly greater than all-trans LYC. Micellarized carotenoids were relatively stable in micelles incubated in the cell culture environment and after accumulation in Caco-2 cells. These data suggest that the greater bioaccessibility of cis compared with all-trans isomers of LYC contributes to the enrichment of the cis isomers in tissues and that gac fruit is an excellent source of bioaccessible LYC and provitamin A carotenoids.     

A food-based formulation provides lycopene with the same bioavailability to humans as that from tomato paste

Lycopene from fresh and unprocessed tomatoes is poorly absorbed by humans. Absorption of lycopene is higher from processed foods such as tomato paste and tomato juice heated in oil. The aim of the present study was to develop a food-grade lycopene formulation that is bioavailable in humans. A formulation of lycopene named "lactolycopene" has been designed in which lycopene is entrapped with whey proteins. Healthy subjects (n = 33; 13 men and 20 women) participated and were allocated randomly to one of the three treatment groups. After a 3-wk deprivation of dietary lycopene, subjects ingested 25 mg lycopene/d for 8 wk from lactolycopene, tomato paste (positive control) or a placebo of whey proteins while consuming their self-selected diets. Plasma lycopene concentrations reached a maximum after 2 wk of supplementation in both lycopene-treated groups and then a plateau was maintained until the end of the treatment. Increases in plasma lycopene at wk 8 were not different between supplemented groups (mean +/- SEM): 0.58 +/- 0.13 micromol/L with lactolycopene and 0.47 plus minus 0.07 micromol/L with tomato paste, although they were different from the control (P < 0.001). Similar time-concentration curves of lycopene incorporation were observed in buccal mucosa cells. Although lycopene was present mainly as all-trans isomers (>90%) in both lycopene supplements, plasma lycopene enrichment consisted of 40% as all-trans and 60% as cis isomers. The precursor of lycopene, phytofluene, was better absorbed than lycopene itself. The lactolycopene formulation and tomato paste exhibited similar lycopene bioavailability in plasma and buccal mucosa cells in humans.     

Lycopene inhibits disease progression in patients with benign prostate hyperplasia

Lycopene is a promising nutritional component for chemoprevention of prostate cancer (PCa). A possibly beneficial role of lycopene in patients diagnosed with benign prostate hyperplasia (BPH), who are at increased risk of developing PCa, has been suggested, although clinical data are lacking. Therefore, this pilot study aimed to investigate the effects of lycopene supplementation in elderly men diagnosed with BPH. A total of 40 patients with histologically proven BPH free of PCa were randomized to receive either lycopene at a dose of 15 mg/d or placebo for 6 mo. The effects of the intervention on carotenoid status, clinical diagnostic markers of prostate proliferation, and symptoms of the disease were assessed. The primary endpoint of the study was the inhibition or reduction of increased serum prostate-specific antigen (PSA) levels. The 6-mo lycopene supplementation decreased PSA levels in men (P < 0.05), whereas there was no change in the placebo group. The plasma lycopene concentration increased in the group taking lycopene (P < 0.0001) but other plasma carotenoids were not affected. Whereas progression of prostate enlargement occurred in the placebo group as assessed by trans-rectal ultrasonography (P < 0.05) and digital rectal examination (P < 0.01), the prostate did not enlarge in the lycopene group. Symptoms of the disease, as assessed via the International Prostate Symptom Score questionnaire, were improved in both groups with a significantly greater effect in men taking lycopene supplements. In conclusion, lycopene inhibited progression of BPH.     

Modification of lymphocyte DNA damage by carotenoid supplementation in postmenopausal women

BACKGROUND: Oxidative stress has been implicated in the pathogenesis of chronic diseases related to aging such as cancer and cardiovascular disease. Carotenoids could be a part of a protective strategy to minimize oxidative damage in vulnerable populations, such as the elderly. OBJECTIVE: Our aim was to determine the protective effect of carotenoids against DNA damage. DESIGN: A randomized, double-blind, placebo-controlled intervention study was conducted. Thirty-seven healthy, nonsmoking postmenopausal women aged 50-70 y were randomly assigned to 1 of 5 groups and were instructed to consume a daily dose of mixed carotenoids (beta-carotene, lutein, and lycopene; 4 mg each), 12 mg of a single carotenoid (beta-carotene, lutein, or lycopene), or placebo for 56 d. Plasma carotenoid concentrations were analyzed by using HPLC, and lymphocyte DNA damage was measured by using a single-cell gel electrophoresis (comet) assay. RESULTS: At day 57, all carotenoid-supplemented groups showed significantly lower endogenous DNA damage than at baseline (P < 0.01), whereas the placebo group did not show any significant change. Significantly less (P < 0.05) endogenous DNA damage was found as early as day 15 in the mixed carotenoid (P < 0.01) and beta-carotene (P < 0.05) groups. CONCLUSIONS: The results indicate that carotenoid supplementation decreases DNA damage and that a combination of carotenoids (4 mg each of lutein, beta-carotene, and lycopene), an intake that can be achieved by diet, or a larger dose (12 mg) of individual carotenoids exerts protection against DNA damage.     

Lycopene supplementation elevates circulating insulin-like growth factor binding protein-1 and -2 concentrations in persons at greater risk of colorectal cancer

BACKGROUND: Higher circulating insulin-like growth factor I (IGF-I) concentrations have been related to a greater risk of cancer. Lycopene intake is inversely associated with cancer risk, and experimental studies have shown that it may affect the IGF system, possibly through an effect on IGF-binding proteins (IGFBPs). OBJECTIVE: The objective of our study was to investigate the effect of an 8-wk supplementation with tomato-derived lycopene (30 mg/d) on serum concentrations of total IGF-I, IGF-II, IGFBP-1, IGFBP-2, and IGFBP-3. DESIGN: We conducted a randomized, placebo-controlled, double-blinded crossover study in 40 men and 31 postmenopausal women with a family history of colorectal cancer, a personal history of colorectal adenoma, or both. RESULTS: Lycopene supplementation significantly (P = 0.01) increased serum IGFBP-1 concentrations in women (median relative difference between serum IGFBP-1 concentrations after lycopene supplementation and after placebo, 21.7%). Serum IGFBP-2 concentrations were higher in both men and women after lycopene supplementation than after placebo, but to a lesser extent (mean relative difference 8.2%; 95% CI: 0.7%, 15.6% in men and 7.8%; 95% CI: -5.0%, 20.6% in women). Total IGF-I, IGF-II, and IGFBP-3 concentrations were not significantly altered by lycopene supplementation. CONCLUSIONS: This is the first study known to show that lycopene supplementation may increase circulating IGFBP-1 and IGFBP-2 concentrations. Because of high interindividual variations in IGFBP-1 and IGFBP-2 effects, these results should be confirmed in larger randomized intervention studies.     

Non-nutritive bioactive constituents of plants: lycopene,lutein and zeaxanthin

Lycopene, lutein, and zeaxanthin are major carotenoids in human blood and tissues but unlike beta-carotene do not contribute to vitamin A supply. These carotenoids are efficient antioxidants quenching singlet molecular oxygen which is formed in photooxidative processes and thus may contribute to the prevention of light-exposed tissue, skin and eyes, from light-induced damage. Increasing lycopene intake by daily consumption of tomato paste over a period of ten weeks provides protection against erythema formation following UV-irradiation. Lycopene and other carotenoids may be used as oral sun protectants and contribute to the maintenance of skin health. The yellow color of the macula lutea is due to the presence of the carotenoid pigments lutein and zeaxanthin. These macula carotenoids are suggested to play a role in protection against light-dependent damage. Filtering of blue light and scavenging of reactive intermediates generated in photooxidation are considered to be the underlying protective mechanisms. Epidemiological studies provide evidence that an increased consumption of lutein is associated with a lowered risk for age-related macular degeneration, a disease with increasing incidence in the elderly.     

Dietary Intake and Serum Level of Carotenoids in Lung Cancer Patients: A Case-Control Study

The aim of this study was to compare the dietary intake and serum levels of some selected carotenoids of lung cancer patients with healthy subjects. Thirty-five lung cancer patients and 33 healthy people were enrolled into this case-control study. Daily intake of nutrients was estimated using a semiquantitative food frequency questionnaire and a 3-day 24-h food recall questionnaire. The concentration of serum beta-carotene and lycopene were analyzed using a high performance liquid chromatography method. Case and control groups did not differ by the means of age, gender, smoking habits, weight, body mass index, mean daily energy intake, mean daily fat intake, and the percentage of daily energy provided by fat to total daily energy intake. The beta-carotene and lycopene intake of the case subjects was 96% and 195% greater than that of the control subjects. Daily intake of fruits and vegetables in the cancer group was higher than the control group. However, the serum concentration of 118% beta-carotene and 60% lycopene were higher in the control group. Despite a higher daily dietary intake of beta-carotene and lycopene by lung cancer patients, serum beta-carotene and lycopene concentrations were significantly lower than the group without cancer.     

Lycopene--a natural antioxidant

Lycopene is a carotenoid found predominantly in tomatoes and tomato products. In contrast to beta-carotene it is not a precursor of vitamin A in humans. Lycopene is not destroyed during food processing, moreover its bioavailability improves. Lycopene is the most powerful antioxidant amongst carotenoids. Beside the antioxidant effect it influences the expression of various proteins (enzymes of biotransformation, cyclin D1, connexins). According to epidemiologic studies tomato lycopene may reduce the risk of prostate cancer and cardiovascular diseases. Positive effects are also hypothesized in case of other diseases such as osteoporosis, neurodegenerative diseases and hypertension. Neither adverse effects upon lycopene supplementation nor lycopene toxicity have been reported. Therefore, several arguments support the consumption of natural lycopene, whilst there are no contraindications according to the present knowledge.