Lycopene, a carotenoid, is used for preventing atherosclerosis, cardiovascular disease and cancer. It is also used to treat prostate cancer and asthma. It is the pigment that gives some fruits and vegetables, such as tomatoes, their red color. It is also found in watermelons, pink grapefruits, apricots and pink guavas.
Lycopene supplements are used orally to treat prostate cancer. High lycopene plasma levels from dietary intake seem to reduce prostate cancer risk by 83% compared with men with low plasma lycopene levels. Dietary lycopene and other carotenoids are used to prevent lung cancer. There is epidemiological evidence that consumption of lycopene from foods (12 mg per day or more for men, and 6.5 mg per day or more for women) decreases the risk of lung cancer in non-smoking men aged 40 to 75, and non-smoking women aged 30 to 55.
Lycopene has the most potent antioxidant activity of any common carotenoid. It might reduce cancer risk by scavenging free radicals and preventing oxidative damage to DNA. Researchers are interested in lycopene as a prevention of cancer, atherosclerosis and other conditions. Evidence suggests that lycopene may decrease cholesterol synthesis and increase removal of LDL cholesterol from circulation. Lycopene seems to have some direct effects within the prostate, specifically up-regulating tumor suppressor genes.
Lycopene may be immune stimulating and have thymic support properties that may make them helpful for certain health conditions such as prostate cancer, asthma, atherosclerosis, immunity and macular degeneration (vision).
Published Clinical Studiesclin
Antioxidants, carotenoids, and risk of rectal cancer.1
Murtaugh MA, Ma KN, Benson J, Curtin K, Caan B, Slattery ML.
Health Research Center, Department of Family and Preventive Medicine, University of Utah, Salt Lake City, UT.
Numerous properties suggest that antioxidants and carotenoids may be valuable chemopreventive agents. A population-based case-control study of 952 rectal cancer cases and 1,205 controls from Northern California and Utah was conducted between September 1997 and February 2002. Detailed diet history, medical history, and lifestyle factors interviews were conducted. Dietary antioxidants were not associated with rectal cancer risk in men. For women, relative to the highest level of intake, low intake of dietary lycopene (odds ratio (OR) = 1.7, 95% confidence interval (CI): 1.0, 2.8) or vitamin E (OR = 2.2, 95% CI: 1.1, 4.3) was associated with an increased risk of rectal cancer. Alpha-, beta-, and gamma-tocopherol were associated with an approximate twofold increased risk of rectal cancer in women. Associations were stronger for women aged >/==" BORDER="0">60 years for vitamin E and tocopherols (alpha-tocopherol OR = 3.6, 95% CI: 1.4, 9.4; gamma-tocopherol OR = 5.3, 95% CI: 2.1, 13.2; delta-tocopherol OR = 1.9, 95% CI: 0.9, 4.0), except for beta-tocopherol, for which risk increased twofold for all women. Associations differed by estrogen status for beta-carotene, lycopene, and vitamin E. These results suggest that vitamin E and lycopene may modestly reduce the risk of rectal cancer in women.
PMID: 14693657 [PubMed - in process]
2
Plasma lycopene, other carotenoids, and retinol and the risk of cardiovascular disease in women.
Sesso HD, Buring JE, Norkus EP, Gaziano JM.
Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02215, USA. hsesso@hsph.harvard.edu
BACKGROUND: Growing evidence suggests that lycopene has significant in vitro antioxidant potential. Lycopene has rarely been tested in prospective studies for its role in cardiovascular disease (CVD) prevention. OBJECTIVE: We examined the association between plasma lycopene and the risk of CVD in middle-aged and elderly women. DESIGN: A prospective, nested, case-control study was conducted in 39 876 women initially free of CVD and cancer in the Women's Health Study. Baseline blood samples were collected from 28 345 (71%) of the women. During a mean of 4.8 y of follow-up, we identified 483 CVD cases and 483 control subjects matched by age, smoking status, and follow-up time. Plasma lycopene, other carotenoids, retinol, and total cholesterol were measured. RESULTS: In analyses matched for age and smoking, with adjustment for plasma cholesterol, the relative risks (RRs) and 95% CIs of CVD in increasing quartiles of plasma lycopene were 1.00 (referent), 0.78 (95% CI: 0.55, 1.11), 0.56 (0.39, 0.82), and 0.62 (0.43, 0.90). In multivariate models, the RRs were 1.00 (referent), 0.94 (0.60, 1.49), 0.62 (0.39, 1.00), and 0.67 (0.41, 1.11); those in the upper compared with the lower half of plasma lycopene had an RR of 0.66 (0.47, 0.95). For CVD, exclusive of angina, women in the upper 3 quartiles had a significant multivariate 50% risk reduction compared with those in the lowest quartile. The stepwise addition of individual plasma carotenoids did not affect the RRs. CONCLUSIONS: Higher plasma lycopene concentrations are associated with a lower risk of CVD in women. These findings require confirmation in other cohorts, and the determinants of plasma lycopene concentrations need to be better understood.
PMID: 14684396 [PubMed - in process]
Dietary carotenoid intake as a predictor of bone mineral density.3
Wattanapenpaiboon N, Lukito W, Wahlqvist ML, Strauss BJ.
Asia Pacific Health and Nutrition Centre, Monash Asia Institute, Monash University, Melbourne, VIC, Australia. tikky.w@adm.monash.edu.au
Our understanding of the influence of nutrition on bone health is limited because most studies concentrate on the role of calcium and protein, while other nutrients receive less attention. Recent evidence shows a positive link between fruit and vegetable consumption and bone health. In the present study, the relationships of dietary intakes of preformed retinol and carotenoids, one group of phytonutrients abundant in fruit and vegetables, were examined in an Anglo-Celtic Australian population of 68 men and 137 women. Bone mass of total body and lumbar spine were positively related to lycopene intake in men, and to lycopene and lutein/zeaxanthin intake in premenopausal women. In addition, a positive association of lumbar spine bone mass with dietary beta-carotene intake was observed in postmenopausal women. No relationship was found between dietary retinol intake and bone mineral status. The finding of the present study suggests a beneficial effect of fruit and vegetable consumption, as indicated by dietary carotenoid intake, on bone health, possibly via an antioxidant mechanism.
PMID: 14672872 [PubMed - in process]
Lycopene, beta-carotene, and colorectal adenomas.4
Erhardt JG, Meisner C, Bode JC, Bode C.
Department of Physiology of Nutrition, Hohenheim University, Garbenstrasse 28, D-70599 Stuttgart, Germany.
BACKGROUND: Epidemiologic studies found that high tomato intakes reduce the risk of colorectal cancers. This beneficial effect is assumed to be caused by high intakes of lycopene, a carotenoid with strong antioxidant activity that is present predominantly in tomatoes. OBJECTIVE: We assessed the relation between plasma lycopene concentrations and colorectal adenomas, the precursors for most colorectal cancers. In addition, the concentrations of 2 other antioxidants, beta-carotene and alpha-tocopherol, were measured. DESIGN: White subjects undergoing a complete colonoscopy were included in the study (73 with adenomas, 63 without any polyps, and 29 with hyperplastic polyps). A detailed dietary history and information on alcohol consumption and smoking habits were collected from all subjects. Plasma lycopene, beta-carotene, and alpha-tocopherol concentrations were measured by using HPLC. RESULTS: Patients with adenomas and control subjects without polyps did not differ significantly in body mass index; intakes of energy, fat, protein, carbohydrates, fiber, beta-carotene, and alcohol; or prevalence of smoking, but patients with adenomas were slightly older. The median plasma lycopene concentration was significantly lower in the adenoma group than in the control group (-35%; P = 0.016). The median plasma beta-carotene concentration also tended to be lower in the adenoma group (-25.5%), but the difference was not significant. In the multiple logistic regression, only smoking (odds ratio: 3.02; 95% CI: 1.46, 6.25; P = 0.003) and a plasma lycopene concentration < 70 microg/L (odds ratio: 2.31; 1.12, 4.77; P = 0.023) were risk factors for adenomatous polyps. Patients with hyperplastic polyps did not differ significantly from control subjects in any variable. CONCLUSION: Our findings support the hypothesis that lycopene contributes to the protective effect of high tomato intakes against the risk of colorectal adenomas.
PMID: 14668286 [PubMed - indexed for MEDLINE]
Oxidative conversion of carotenoids to retinoids and other products.5
Nagao A.
National Food Research Institute, Tsukuba, Ibaraki 305-8642, Japan.
In vertebrates, provitamin A carotenoids are converted to retinal by beta-carotene-15,15'-dioxygenase. The enzyme activity is expressed specifically in intestinal epithelium and in liver. The intestinal enzyme not only plays an important role in providing animals with vitamin A, but also determines whether provitamin A carotenoids are converted to vitamin A or circulated in the body as intact carotenoids. We have found that a high fat diet enhanced the beta-carotene dioxygenase activity together with the cellular retinol binding protein type II level in rat intestines. Flavonols with a catechol structure in the B-ring and 2,6-di-tert-butyl-4-methylphenol inhibited the dioxygenase activity of pig intestinal homogenates and the conversion of beta-carotene to retinol in Caco-2 human intestinal cells. Thus, the bioavailability of dietary provitamin A carotenoids might be modulated by the other food components ingested. Regulation of the dioxygenase activity and its relation to the retinoid metabolism as well as to lipid metabolism deserve further study. In contrast to enzymatic cleavage, it is known that both retinal and beta-apocarotenals are formed in vitro from beta-carotene by chemical transformation, which cleaves conjugated double bonds at random positions under various oxidative conditions. Moreover, recent studies have indicated that the oxidation products formed by chemical transformation might have specific actions on the proliferation of certain cancer cells. We have found that lycopene, a typical nonprovitamin A carotenoid, was cleaved in vitro to acycloretinal, acycloretinoic acid and apolycopenals in a nonenzymatic manner, and that the mixture of oxidation products of lycopene induced apoptosis of HL-60 human promyelocytic leukemia cells. Thus, it is worth evaluating the formation of oxidation products and their biological actions, in order to elucidate the underlying mechanisms of the beneficial effects of carotenoids on human health.
PMID: 14704326 [PubMed - in process]
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