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.     

The consumption of processed tomato products enhances plasma lycopene concentrations in association with a reduced lipoprotein sensitivity to oxidative damage

Lycopene, the predominant carotenoid in tomatoes, is hypothesized to mediate the health benefits of tomato products. We designed a study to examine the change in plasma lycopene and resistance of lipoproteins to ex vivo oxidative stress. Healthy individuals (n = 60; age >40 y; 30 men/30 women) consumed a lycopene-free diet for 1 wk and were subsequently randomized to receive 35 +/- 1, 23 +/- 1 or 25 +/- 1 mg lycopene/d from Campbell's Condensed Tomato Soup (CS), Campbell's Ready To Serve Tomato Soup (RTS) or V8 Vegetable Juice (V8), respectively, for 15 d. Total plasma lycopene concentrations decreased from 0.499 +/- 0.044 to 0.322 +/- 0.027 (35%, P < 0.0001) micro mol/L for the 60 participants during the 7-d washout period. After intervention, total lycopene concentrations increased for those consuming CS, RTS and V8 (compared with the washout period for each group) to 0.784 +/- 0.083 (123%, P < 0.0001), 0.545 +/- 0.061 (57%, P < 0.01) and 0.569 +/- 0.061 (112%, P < 0.0001) micro mol/L, respectively. The concentrations of all lycopene isomers decreased during the washout period. As a percentage of plasma total lycopene isomers for the 60 subjects, all-trans-lycopene decreased from 44.4 +/- 1.2 to 39.6 +/- 1.2 (P < 0.0001), whereas total cis-lycopene isomers increased from 55.6 +/- 1.2 to 60.4 +/- 1.2 (P < 0.0001) during the washout period, a shift that was reversed by consumption of tomato products for 15 d. The ex vivo lipoprotein oxidation lag period, used as a measure of antioxidant capacity, increased significantly from 64.7 +/- 2.4 min at the end of the washout period (all groups) to 70.1 +/- 4.0 (P < 0.05), 68.3 +/- 2.4 (P < 0.05) and 71.7 +/- 4.0 min (P < 0.01) after treatment for the CS, RTS and V8 groups, respectively. This study shows that lycopene concentrations and isomer patterns change rapidly with variation in dietary intake. In addition, 15 d of tomato product consumption significantly enhanced the protection of lipoproteins to ex vivo oxidative stress.     

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.     

Dietary lycopene,tomato-based food products and cardiovascular disease in women

In addition to the inverse association of dietary lycopene with various cancers, studies suggest a role for lycopene in cardiovascular disease (CVD) prevention. We determined whether the intake of lycopene or tomato-based foods is associated with the risk of CVD in a prospective cohort of 39,876 middle-aged and older women initially free of CVD and cancer. Participants completed a food-frequency questionnaire and provided self-reports of coronary risk factors. Dietary lycopene levels were divided into quintiles, and primary lycopene food sources (total tomato-based products, including tomatoes, tomato juice, tomato sauce and pizza) were categorized. During 7.2 y of follow-up, 719 CVD cases (including myocardial infarction, stroke, revascularization and CVD death) occurred. Compared with women in the 1st quintile of lycopene, those in increasing quintiles had multivariate relative risks (RR) of CVD of 1.11, 1.14, 1.15 and 0.90 (P for trend = 0.34). For the consumption of tomato-based products, women consuming 1.5 to <4, 4 to <7, 7 to <10 and >or=10 servings/wk had RR (95% CI) of CVD of 1.02 (0.82-1.26), 1.04 (0.82-1.31), 0.68 (0.49-0.96) and 0.71 (0.42-1.17) (P for trend = 0.029) compared with women consuming <1.5 servings/wk. Among lycopene food sources, those in the highest levels of tomato sauce (>or=2 servings/wk) and pizza intake (>or=2 servings/wk), with multivariate RR of 0.76 (0.55-1.05) and 0.66 (0.37-1.18), respectively, had potential reductions in CVD risk. Dietary lycopene was not strongly associated with the risk of CVD. However, the possible inverse associations noted for higher levels of tomato-based products, particularly tomato sauce and pizza, with CVD suggest that dietary lycopene or other phytochemicals consumed as oil-based tomato products confer cardiovascular benefits.     

Consumption of watermelon juice increases plasma concentrations of lycopene and beta-carotene in humans

Watermelon is a rich natural source of lycopene, a carotenoid of great interest because of its antioxidant capacity and potential health benefits. Assessment of bioavailability of lycopene from foods has been limited to tomato products, in which heat processing promotes lycopene bioavailability. We examined the bioavailability of lycopene from fresh-frozen watermelon juice in a 19-wk crossover study. Healthy, nonsmoking adults (36-69 y) completed three 3-wk treatment periods, each with a controlled, weight-maintenance diet. Treatment periods were preceded by "washout" periods of 2-4 wk during which lycopene-rich foods were restricted. All 23 subjects consumed the W-20 (20.1 mg/d lycopene, 2.5 mg/d beta-carotene from watermelon juice) and C-0 treatments (controlled diet, no juice). As a third treatment, subjects consumed either the W-40 (40.2 mg/d lycopene, 5.0 mg/d beta-carotene from watermelon juice, n = 12) or T-20 treatment (18.4 mg/d lycopene, 0.6 mg/d beta-carotene from tomato juice, n = 10). After 3 wk of treatment, plasma lycopene concentrations for the W-20, W-40, T-20 and C-0 treatments were (least squares means +/- SEM) 1078 +/- 106, 1183 +/- 139, 960 +/- 117 and 272 +/- 27 nmol/L, respectively. Plasma concentrations of beta-carotene were significantly greater after W-20 (574 +/- 49 nmol/L) and W-40 (694 +/- 73 nmol/L) treatments than after the C-0 treatment (313 +/- 27 nmol/L). Plasma lycopene concentrations did not differ at wk 3 after W-20, W-40 and T-20 treatments, indicating that lycopene was bioavailable from both fresh-frozen watermelon juice and canned tomato juice, and that a dose-response effect was not apparent in plasma when the watermelon dose was doubled.     

Tangerine tomatoes increase total and tetra-cis-lycopene isomer concentrations more than red tomatoes in healthy adult humans

Lycopene, or the foods that contain it, may prevent prostate cancer. Studies suggest that some cis-lycopene isomers are more bioavailable than the trans-lycopene isomer. We hypothesized that tangerine tomatoes, which predominantly contain the tetra-cis isomer, should be a good source of bioavailable lycopene. We fed lunches containing 300 g tangerine or red tomato sauce per day to 21 healthy adults in a double-blind crossover design. We collected blood at baseline and after each treatment and washout period. We measured tetra-cis, other cis, and trans lycopene, as well as other carotenoids, by reversed-phase high-performance liquid chromatography. Both tomato sauces increased lycopene concentrations in blood, but the tangerine tomato sauce caused a greater increase of total and tetra-cis-lycopene. The cis isomer(s) may also have facilitated absorption of the trans-lycopene isomer. Indices of oxidative damage decreased as serum lycopene concentrations increased. Our results suggest that total lycopene concentrations can be increased by substituting tetra-cis-lycopene-rich tangerine tomatoes for common red tomatoes in the diet.     

Comparative multiple dose plasma kinetics of lycopene administered in tomato juice,tomato soup or lycopene tablets

Summary. Background: Lycopene is mainly provided in tomato and tomato products in Western diet. Among other factors the systemic availability of lycopene from natural sources is dependent on release from the cell matrix as achieved by food processing. Aims of the study: The purpose of this study was to compare plasma concentration responses of total lycopene and its major isomers to dosing of the carotenoid as tomato juice, tomato soup or tablets containing synthetic lycopene. Methods: Intake of lycopene rich food products was restricted throughout this randomized, parallel group study, including 6 volunteers per group. Following a 14 day lycopene depletion phase subjects ingested 20 mg of lycopene daily for 8 days as tomato juice, soup prepared from tomato paste or lycopene tablets. Lycopene plasma concentrations were monitored throughout the depletion and dosing phases and for 22 days post-dosing and kinetics were evaluated using both empirical and compartmental modelling. Results: Irrespective of the lycopene treatment all-E lycopene was the predominant lycopene isomer, whereas 5-Z lycopene was the most abundant Z isomer. Plasma concentration response of total and all-E lycopene to dosing of the carotenoid in tablets and tomato soup was comparable but exceeded that of intake in tomato juice. No differences were noted in dose normalized 5-Z lycopene concentrations between groups. The estimates of efficient half-life were approximately 5 and 9 days for all-E and 5-Z lycopene, respectively. Conclusions: The systemic availability of synthetic lycopene from a tablet formulation is comparable to that observed from processed tomatoes (soup from tomato paste) and superior to that from tomato juice. No differences were observed in disposition kinetics of natural and synthetic lycopene. The synthetic lycopene tablet formulation used in this investigation may be of value for future clinical investigations.     

Tomato-based food products are related to clinically modest improvements in selected coronary biomarkers in women

Few epidemiologic studies have examined the potential cardiovascular mechanisms of tomato-based food products, the primary dietary source of lycopene. We examined the cross-sectional association between tomato-based food product intake and coronary biomarkers in the Women's Health Study. Tomato-based food products (tomatoes, tomato juice, tomato sauce, pizza) were summed from a semiquantitative FFQ and multiple risk factors ascertained. Plasma from baseline blood samples were assayed for lipids, lipoproteins, hemoglobin A1c, C-reactive protein, fibrinogen, soluble intracellular adhesion molecule-1, and creatinine. A total of 27,261 women aged ≥45 y who were free of cardiovascular disease and cancer provided relevant data for this study. Tomato-based food product intake was modest, with 84% of women consuming <1 serving/d, but those with greater intake had healthier lifestyle and dietary habits. Women consuming ≥10 compared with <1.5 servings/wk of tomato-based food products had significant but clinically modest improvements in total cholesterol (TC) (5.38 vs. 5.51 mmol/L; P = 0.029), the TC:HDL cholesterol ratio (4.08 vs. 4.22; P = 0.046), and hemoglobin A1c (5.02 vs. 5.13%; P < 0.001) in multivariable models. Considering clinical cutpoints, women consuming ≥10 compared with <1.5 servings/wk were 31% (95% CI = 6%, 50%), 40% (95% CI = 13%, 59%), and 66% (95% CI = 20%, 86%) less likely to have elevated TC (≥6.21 mmol/L), LDL cholesterol (≥4.14 mmol/L), and hemoglobin A1c (≥6%), respectively. Other coronary biomarkers were unassociated with tomato-based food products. In conclusion, women consuming ≥10 compared with <1.5 servings/wk of tomato-based food products had clinically modest but significant improvements in TC, the TC:HDL cholesterol ratio, and hemoglobin A1c but not other coronary biomarkers.     

HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia

BACKGROUND: Orange juice-a rich source of vitamin C, folate, and flavonoids such as hesperidin-induces hypocholesterolemic responses in animals. OBJECTIVE: We determined whether orange juice beneficially altered blood lipids in subjects with moderate hypercholesterolemia. DESIGN: The sample consisted of 16 healthy men and 9 healthy women with elevated plasma total and LDL-cholesterol and normal plasma triacylglycerol concentrations. Participants incorporated 1, 2, or 3 cups (250 mL each) of orange juice sequentially into their diets, each dose over a period of 4 wk. This was followed by a 5-wk washout period. Plasma lipid, folate, homocyst(e)ine, and vitamin C (a compliance marker) concentrations were measured at baseline, after each treatment, and after the washout period. RESULTS: Consumption of 750 mL but not of 250 or 500 mL orange juice daily increased HDL-cholesterol concentrations by 21% (P: < 0.001), triacylglycerol concentrations by 30% (from 1.56 +/- 0.72 to 2.03 +/- 0.91 mmol/L; P: < 0.02), and folate concentrations by 18% (P: < 0.01); decreased the LDL-HDL cholesterol ratio by 16% (P: < 0.005); and did not affect homocyst(e)ine concentrations. Plasma vitamin C concentrations increased significantly during each dietary period (2.1, 3.1, and 3.8 times, respectively). CONCLUSIONS: Orange juice (750 mL/d) improved blood lipid profiles in hypercholesterolemic subjects, confirming recommendations to consume >/=5-10 servings of fruit and vegetables daily.     

Prolonged tomato juice consumption has no effect on cell-mediated immunity of well-nourished elderly men and women

The immunomodulatory potential of carotenoids has been investigated thoroughly only for beta-carotene. Data on the immunomodulatory activity of other carotenoids such as lycopene are scarce. The objective of this study was to investigate the effects of prolonged tomato juice consumption on cell-mediated immunity of well-nourished healthy elderly persons. In an intervention study, 33 female and 20 male subjects (aged 63-86 y) consumed 330 mL/d tomato juice (47.1 mg/d lycopene) or mineral water for 8 wk. Immune status was assessed by measuring number and lytic activity of natural killer (NK) cells, secretion of cytokines [interleukin (IL)-2, IL-4, tumor necrosis factor-alpha (TNF-alpha)] by activated peripheral blood mononuclear cells (PBMC), lymphocyte proliferation, and delayed-type hypersensitivity (DTH) skin responses. Tomato juice consumption resulted in significantly increased plasma lycopene and beta-carotene concentrations over time. In both treatment groups, TNF-alpha and IL-4 secretion were increased at the end of the intervention period, whereas IL-2 secretion was decreased. Tomato juice consumption had no effect on lymphocyte proliferation, DTH or the number of NK cells. Lytic activity of NK cells was increased in both groups at the end of the intervention period. In conclusion, these results show that prolonged tomato juice consumption increased plasma lycopene concentrations without significantly affecting cell-mediated immunity in well-nourished elderly subjects.     

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.     

Moderate intervention with carotenoid-rich vegetable products reduces lipid peroxidation in men

Because of their antioxidant properties, carotenoids may have beneficial effects in preventing cancer and cardiovascular disease. However, in humans consuming carotenoid-rich vegetables, data concerning the antioxidant effects of carotenoids are rather scarce. A human intervention trial was conducted, therefore, to determine whether a moderately increased consumption of carotenoid-rich vegetables would influence the antioxidant status in 23 healthy men. This short-term feeding study lasted 8 wk during which the men consumed a low carotenoid diet. A 2-wk low carotenoid period was followed by daily consumption of 330 mL tomato juice, then by 330 mL carrot juice and then by 10 g of spinach powder, each for 2 wk. Antioxidant status [water-soluble antioxidants in serum, ferric reducing ability of plasma (FRAP) and antioxidant enzyme activities] and lipid peroxidation (plasma malondialdehyde and ex vivo oxidation of LDL) were determined. In a subgroup of 10 men, lipoprotein carotenoids were measured. The consumption of carotenoid-rich vegetables significantly increased selected carotenoids in lipoproteins but had only minor effects on their relative distribution pattern. Tomato juice consumption reduced plasma thiobarbituric acid reactive substances (TBARS) by 12% (P: < 0.05) and lipoprotein oxidizability in terms of an increased lag time (18%, P: < 0.05). Carrot juice and spinach powder had no effect on lipid peroxidation. Water-soluble antioxidants, FRAP, glutathione peroxidase and reductase activities did not change during any study period. In evaluating the low carotenoid diet, we conclude that the additional consumption of carotenoid-rich vegetable products enhanced lipoprotein carotenoid concentrations, but only tomato juice reduced LDL oxidation in healthy men.     

Antioxidant capacity of lycopene-containing foods

Increased consumption of tomatoes and tomato products has been associated with decreased cancer risks. One fat-soluble compound identified in tomatoes which may be responsible for this association is lycopene. There may, however, be other antioxidants present in tomato-based foods, and total antioxidant capacity may be another way to rate the health benefits of these foods. In this work, we examined the Trolox-equivalent antioxidant capacity (TEAC) of aqueous and organic extracts of lycopene-containing foods: ketchup, fresh tomatoes, tomato paste, tomato sauce, tomato soup, tomato juice, vegetable juice, canned tomatoes and watermelon. Antioxidant activity in these food extracts was greater in the aqueous versus organic fractions, except for watermelon and tomato sauce where the levels were similar in the two fractions. Lycopene levels in the food samples tested, however, were relatively greater in the organic fractions, with the exception of the two juices, which had similar levels in the two fractions, and two highly concentrated tomato products, tomato paste and ketchup, which had relatively higher lycopene levels in the aqueous fractions. The foods with the highest antioxidant capacity per serving overall (tomato soup was highest) did not have the highest lycopene levels. This indicates that it may be important to consume a variety of tomato-containing products in order to obtain the largest variety of dietary antioxidants possible.     

Antioxidant capacity of lycopene-containing foods

Increased consumption of tomatoes and tomato products has been associated with decreased cancer risks. One fat-soluble compound identified in tomatoes which may be responsible for this association is lycopene. There may, however, be other antioxidants present in tomato-based foods, and total antioxidant capacity may be another way to rate the health benefits of these foods. In this work, we examined the Trolox-equivalent antioxidant capacity (TEAC) of aqueous and organic extracts of lycopene-containing foods: ketchup, fresh tomatoes, tomato paste, tomato sauce, tomato soup, tomato juice, vegetable juice, canned tomatoes and watermelon. Antioxidant activity in these food extracts was greater in the aqueous versus organic fractions, except for watermelon and tomato sauce where the levels were similar in the two fractions. Lycopene levels in the food samples tested, however, were relatively greater in the organic fractions, with the exception of the two juices, which had similar levels in the two fractions, and two highly concentrated tomato products, tomato paste and ketchup, which had relatively higher lycopene levels in the aqueous fractions. The foods with the highest antioxidant capacity per serving overall (tomato soup was highest) did not have the highest lycopene levels. This indicates that it may be important to consume a variety of tomato-containing products in order to obtain the largest variety of dietary antioxidants possible.     

Lycopene from heat-induced cis-isomer-rich tomato sauce is more bioavailable than from all-trans-rich tomato sauce in human subjects

Lycopene is present mainly as cis-isomers in human serum and tissues whereas all-trans-lycopene predominates in tomato products, suggesting that all-trans-lycopene is isomerised in the body or is less bioavailable. The objectives of the present study were to develop processing conditions for tomatoes to obtain products with different cis-trans-lycopene isomer distribution and to assess their bioavailability. Healthy adult subjects (n 12) were recruited for this randomised cross-over trial. Each intervention was preceded by a 2-week washout period. Two tomato sauces, one rich in all-trans-lycopene (32.5 mg total lycopene/100 g sauce; 5 % cis-isomers), the other high in cis-lycopene (26.4 mg total lycopene/100 g sauce; 45 % cis-isomers), were produced by different heat-processing techniques. Each sauce (150 g) was served in a standardised meal at 08.00 hours after overnight fasting. Plasma TAG-rich lipoprotein fractions over 9.5 h following test-meal consumption as a measure of lycopene absorption were obtained and expressed as baseline-corrected area under the concentration v. time curves (AUC), using HPLC-electrochemical detection. AUC values adjusted for the amount lycopene consumed showed that total, total cis-, and all-trans-lycopene responses were significantly higher from the cis-isomer-rich sauce, compared with the all-trans-rich sauce, being 7.30 (sem 1.45) v. 4.74 (sem 1.08) nmol x h/l (P = 0.002), 3.80 (sem 0.76) v. 1.98 (sem 0.37) nmol x h/l (P = 0.0005) and 3.50 (sem 0.76) v. 2.76 (sem 0.76) nmol x h/l (P = 0.01), respectively. The present study demonstrates significant lycopene bioavailability from cis-lycopene-rich tomato sauce and highlights the importance of considering isomer-distribution for lycopene bioavailability. Furthermore, processing parameters can be controlled to alter isomer patterns of tomato products and influence lycopene bioavailability.     

High dose lycopene supplementation increases hepatic cytochrome P4502E1 protein and inflammation in alcohol-fed rats

Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol-induced oxidative stress and inflammation. However, knowledge of possible interactions in vivo between escalating doses of lycopene and chronic alcohol ingestion are lacking. In this study, we investigated potential interactions between alcohol ingestion and lycopene supplementation and their effect on hepatic lycopene concentration, cytochrome P4502E1 (CYP2E1) induction, and inflammation. Fischer 344 rats (6 groups, n = 10 per group) were fed either a liquid ethanol Lieber-DeCarli diet or a control diet (isocaloric maltodextrin substituted for ethanol) with or without lycopene supplementation at 2 doses (1.1 or 3.3 mg x kg body weight(-1) x d(-1)) for 11 wk. Plasma and hepatic concentrations of lycopene isomers were assessed by HPLC analysis. We examined expressions of hepatic CYP2E1 and tumor necrosis factor-alpha (TNFalpha) and the incidence of hepatic inflammatory foci. Both plasma and hepatic lycopene concentrations were greater in alcohol-fed rats than in control rats supplemented with identical doses of lycopene. In contrast, alcohol-fed rats had a lower percentage of lycopene cis isomers in the plasma and the liver compared with control rats fed the same dose of lycopene. Notably, lycopene supplementation at the higher dose significantly induced hepatic CYP2E1 protein, TNFalpha mRNA, and the incidence of inflammatory foci in the alcohol-fed rats but not in the control rats. These data indicate an interaction between chronic alcohol ingestion and lycopene supplementation and suggest a need for caution among individuals consuming high amounts of both alcohol and lycopene.     

Vegetable-borne lutein, lycopene, and beta-carotene compete for incorporation into chylomicrons, with no adverse effect on the medium-term (3-wk) plasma status of carotenoids in humans

BACKGROUND: The results of epidemiologic studies have consistently shown associations between dietary intake or plasma carotenoid status and incidence of cancers and cardiovascular and eye diseases. OBJECTIVE: The aim was to assess whether vegetable-borne carotenoids (lycopene, lutein, and beta-carotene) compete for intestinal absorption and whether this affects the plasma status of carotenoids in the medium term (ie, after 3 wk). DESIGN: During 3-wk periods separated by 3-wk washout periods, 20 women were supplemented with either 96 g tomato purée/d (14.98 mg lycopene + 1.50 mg beta-carotene), 92 g cooked chopped spinach/d (11.93 mg lutein + 7.96 mg beta-carotene), 96 g tomato purée/d + 92 g chopped spinach/d, 96 g tomato purée/d + 2 lutein pills (12 mg lutein), or 92 g chopped spinach/d + 1 lycopene pill (15 mg lycopene). Plasma carotenoids were measured before and after each supplementation period. The subjects also participated in postprandial experiments in which they ingested meals containing double amounts of the supplements described above. Carotenoids were measured in chylomicrons to assess the interaction of carotenoids on absorption. RESULTS: Adding a second carotenoid to a meal that provided a first carotenoid diminished the chylomicron response to the first carotenoid. However, cosupplementation with a second carotenoid of a diet supplemented with a first carotenoid did not diminish the medium-term plasma response to the first carotenoid. CONCLUSION: Consumption of carotenoids from different vegetable sources does not diminish plasma carotenoid concentrations in the medium term, despite the finding in postprandial testing of competitive inhibitory interactions among different carotenoids.     

No differences in DNA damage and antioxidant capacity between intervention groups of healthy, nonsmoking men receiving 2, 5, or 8 servings/day of vegetables and fruit

The effects of different intake levels of vegetables and fruit (VF) on some cancer-relevant biomarkers such as DNA damage and oxidative stress were investigated. In a randomized controlled trial, 64 nonsmoking male subjects were asked to consume a diet with 2 servings of VF/day for 4 wk. Then subjects were randomly assigned to 1 of 3 groups with either a low (2 servings/day), medium (5 servings/day), or high (8 servings/day) intake level of VF for another 4 wk. At the end of study, the plasma lutein, zeaxanthin, alpha-carotene, and beta-carotene but not cryptoxanthin and lycopene concentrations were significantly higher in subjects consuming 8 servings/day than in those receiving 2 servings/day. Different levels of VF consumption and plasma carotenoid concentrations did not result in differences in the levels of endogenous DNA strand breaks, oxidative DNA damage, antigenotoxic capacity of lymphocytes, plasma markers for lipid peroxidation (malondialdehyde, 8-iso-prostaglandin-F2alpha) and antioxidant capacity [trolox-equivalent antioxidant capacity assay]. Thus, although consumption of 8 servings vs 2 servings/day of VF for 4 wk significantly increased the carotenoid level in plasma, there were no differences in DNA damage, lipid peroxidation, and antioxidant capacity markers among healthy, well-nourished, nonsmoking men.     

Effects of ingestion of tomatoes, tomato juice and tomato purée on contents of lycopene isomers, tocopherols and ascorbic acid in human plasma as well as on lycopene isomer pattern

Tomatoes are an important part of the diet. Lycopene, the predominant carotenoid in tomatoes, is hypothesised to mainly mediate the health benefits of tomato products. Anticancer activity of tomato products and lycopene has been suggested by numerous studies. The aim of the present study was to investigate the effect of ingestion of three different tomato-based foodstuffs on plasma contents of lycopene, tocopherols and ascorbic acid. Because isomers of lycopene may have different biological activities, a special interest was to look how the lycopene isomer pattern is changed depending on the matrix of tomato products. Following a 2-week depletion phase volunteers ingested 12.5 mg lycopene/d for 4 weeks comprising tomatoes, tomato juice or tomato purée. The basal levels of lycopene in plasma were comparable for all groups and decreased significantly during the 2 weeks of depletion to approximately half of the basal values. Following intervention, plasma lycopene concentration increased significantly. Conversely, supplementation did not significantly affect levels of tocopherols and ascorbic acid in plasma. Regarding isomers of lycopene, the (Z)-lycopene:(all-E)-lycopene plasma isomer ratio was significantly changed during the study for all groups. A remarkable enrichment of the relative contents of (5Z)-lycopene was observed during the depletion period, which supports the hypothesis that lycopene (Z)-isomers are formed within the human body after ingestion of (all-E)-lycopene. After dietary intervention with lycopene-rich products the isomer ratios returned to those observed at the start of the study. Further investigations will clarify the process of isomerisation in more detail.