Lycopene

Lycopene

Background

Lycopene is a carotenoid, and is present in human serum, liver, adrenal glands, lungs, prostate, colon, and skin at higher levels than other carotenoids. Lycopene has been found to possess antioxidant and antiproliferative properties in animal and in vitro studies, although activity in humans remains controversial.

Numerous epidemiological investigations have correlated high intake of lycopene-containing foods or high lycopene serum levels with reduced incidence of cancer, cardiovascular disease, and macular degeneration. However, estimates of lycopene consumption have been based on reported tomato intake, not on the use of lycopene supplements. Since tomatoes are sources of other nutrients including vitamin C, folate, and potassium, it is not clear that lycopene itself is beneficial.

There is no established definition of "lycopene deficiency," and no direct evidence that repletion of low lycopene levels has any benefit.

Synonyms

ψ, ψ-carotene, all-trans lycopene, lycopersicon, solanorubin, tomato.

Evidence

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidenceGrade*Cancer prevention (general)
Studies have examined large populations to identify which lifestyle factors affect health. Many of these "epidemiologic" or "population" studies suggest a link between diets high in fruits and vegetables and a decreased risk of developing cancer. However, it is not entirely clear which foods are most beneficial, or if reduced cancer is due to other (non-dietary) aspects of a "healthy lifestyle." High levels of lycopene are found in tomatoes and in tomato-based products. Tomatoes are also sources of other nutrients such as vitamin C, folate, and potassium. Several laboratory and human studies examining tomato-based products and blood lycopene levels suggest that lycopene may be associated with a lower risk of developing cancer. However, due to a lack of well-designed human research using lycopene supplements, this issue remains unclear.

C

Breast cancer prevention
Research in animals and observations of large human populations have examined the relationship between developing breast cancer and tomato intake or lycopene levels in the body. The evidence in this area is not clear, and further studies are needed before a firm conclusion can be drawn.

C

Cervical cancer prevention
Observations of large human populations suggest possible benefits of tomato product intake in preventing cervical cancer. However, other studies report no benefits. Research that specifically studies lycopene supplements is lacking.

C

Lung cancer prevention
Several studies observing large populations report a lower risk of developing lung cancer in people who regularly eat tomatoes. However, other studies report no benefits of tomato consumption. Research that specifically studies lycopene supplements is lacking.

C

Prostate cancer prevention
Studies of large populations report mixed results as to whether eating tomatoes/tomato-based products reduces the risk of developing prostate cancer. Research that specifically studies lycopene supplements is lacking.

C

Gastrointestinal tract and colorectal cancer prevention
Multiple studies have examined whether intake of tomatoes or tomato-based products helps prevent digestive tract cancers, including oral, pharyngeal, esophageal, gastric, colon, and rectal. Results have been inconsistent, with some studies reporting significant benefits, and others finding no effects. Research that specifically studies lycopene supplements is limited, and more research is needed in this area before a conclusion can be drawn.

C

Age-related macular degeneration prevention
Based on antioxidant properties observed in laboratory studies, lycopene has been suggested as a preventive therapy for age-related macular degeneration. Preliminary human studies have overall not found a clear benefit. More research is needed before a recommendation can be made.

C

Antioxidant
Laboratory research suggests that lycopene, like other carotenoids, may have antioxidant properties. However, it is not clear if lycopene has these effects in the human body. Results of different studies do not agree with each other, and better research is needed before a firm conclusion can be drawn.

C

Asthma caused by exercise
Laboratory research suggests that lycopene, like other carotenoids, may have antioxidant properties. It has been suggested that antioxidants may be helpful in the prevention of asthma that is caused by exercise. There is limited, poor-quality research in this area, and further evidence is needed before a recommendation can be made.

C

Atherosclerosis ("clogged" arteries) and high cholesterol
It has been suggested that lycopene may be helpful in people with atherosclerosis or high cholesterol, possibly due to antioxidant properties. Several studies have been published in this area, most using tomato juice as a treatment. Results have not agreed with each other, and this issue remains unclear.

C

Sun protection
Lycopene in combination with other carotenoids such as beta-carotene, vitamins C an E, selenium and proanthocyanidins, may help in reducing sunburn. Selected protective effects from UV rays have been observed in small, short-term studies. More research is needed before a firm conclusion can be drawn.

C

Immune stimulation
It has been proposed that lycopene and other carotenoids, such as beta-carotene, may stimulate the immune system. However, several studies of lycopene supplements and tomato juice intake in humans report no effects on the immune system.

D

* Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use (it may not work);
F: Strong scientific evidence against this use (it likely does not work).

Uses based on tradition or theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

AIDS, bladder cancer, breast cancer, cataracts, cognitive function, diabetes mellitus, esophageal cancer, heart disease, inflammatory conditions, laryngeal cancer, mesothelioma, melanoma, ovarian cancer, pancreatic cancer, pancreatitis, Parkinson's disease, periodontal disease, pharyngeal cancer, rheumatoid arthritis, skin cancer, stroke prevention, stomach cancer, urinary tract cancer.

Dosing

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

Cancer prevention : Most research examining prevention of cancer has studied tomato and tomato-based products (tomato sauce or juice), not lycopene supplements specifically. Effectiveness has not been proven.

Immune system enhancement : 13.3 milligrams of lycopene daily, supplied as Lyco-O-Pen®, LycoRed Natural Products Industries Ltd., Israel) has been studied.

Asthma (exercise-induced) : 30 milligrams of lycopene daily, supplied as Lyc-O-Mato® (LycoRed Natural Products Industries Ltd., Israel) has been studied.

Atherosclerosis prevention : 1.243 grams of 6% lycopene oleoresin capsules daily (LycoRed Natural Product Industries Ltd., Israel) has been studied.

Sun protection : 8 milligrams of lycopene in combination with other antioxidants has been studied.

Children (younger than 18 years)

There is not enough scientific evidence to recommend use of lycopene supplements in children.

Safety

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Avoid lycopene in people with allergy/hypersensitivity to lycopene or tomatoes.

Side Effects and Warnings

The safety of lycopene supplements has not been thoroughly studied. Review of available scientific literature finds no reports of serious toxicity or adverse effects from eating tomatoes, tomato-based products, or lycopene supplements. Tomatoes and tomato-based products may be acidic and irritate stomach ulcers.

Pregnancy & Breastfeeding

There is not enough scientific research to recommend use of lycopene supplements during pregnancy and breastfeeding. In one study, lycopene components were found in samples of human breast milk, at approximately 10% of blood concentrations. Amounts of lycopene found in foods are usually assumed to be safe.

References

1. Agarwal S, Rao AV. Tomato lycopene and low density lipoprotein oxidation: a human dietary intervention study. Lipids 1998;33 (10) :981-984.

2. Barber N. The tomato: an important part of the urologist's diet? BJU Int. 2003 Mar;91(4):307-9.

3. Bowen P, Chen L, Stacewicz-Sapuntzakis M, Duncan C, Sharifi R, Ghosh L, Kim HS, Christov-Tzelkov K, van Breemen R. Tomato sauce supplementation and prostate cancer: lycopene accumulation and modulation of biomarkers of carcinogenesis. Exp Biol Med (Maywood). 2002 Nov;227(10):886-93.

4. Broekmans WM, Klopping-Ketelaars IA, Weststrate JA, Tijburg LB, van Poppel G, Vink AA, Berendschot TT, Bots ML, Castenmiller WA, Kardinaal AF. Decreased carotenoid concentrations due to dietary sucrose polyesters do not affect possible markers of disease risk in humans. J Nutr. 2003 Mar;133(3):720-6.

5. Bureau I, Laporte F, Favier M, Faure H, Fields M, Favier AE, Roussel AM. No antioxidant effect of combined HRT on LDL oxidizability and oxidative stress biomarkers in treated post-menopausal women. J Am Coll Nutr. 2002 Aug;21(4):333-8.

6. Cerhan JR, Saag KG, Merlino LA, Mikuls TR, Criswell LA. Antioxidant micronutrients and risk of rheumatoid arthritis in a cohort of older women. Am J Epidemiol. 2003 Feb 15;157(4):345-54.

7. Chen G, Djuric Z. Detection of 2,6-cyclolycopene-1,5-diol in breast nipple aspirate fluids and plasma: a potential marker of oxidative stress. Cancer Epidemiol Biomarkers Prev. 2002 Dec;11(12):1592-6.

8. Clarke R, Armitage J. Antioxidant vitamins and risk of cardiovascular disease. Review of large-scale randomized trials. Cardiovasc Drugs Ther. 2002 Sep;16(5):411-5.

9. Corridan BM, O'Donoghue M, Hughes DA, et al. Low-dose supplementation with lycopene or beta-carotene does not enhance cell-mediated immunity in healthy free-living elderly humans. Eur J Clin Nutr 2001;55(8):627-635.

10. Dietrich M, Block G, Norkus EP, Hudes M, Traber MG, Cross CE, Packer L. Smoking and exposure to environmental tobacco smoke decrease some plasma antioxidants and increase gamma-tocopherol in vivo after adjustment for dietary antioxidant intakes. Am J Clin Nutr. 2003 Jan;77(1):160-6.

11. Djuric Z, Uhley VE, Naegeli L, Lababidi S, Macha S, Heilbrun LK. Plasma carotenoids, tocopherols, and antioxidant capacity in a 12-week intervention study to reduce fat and/or energy intakes. Nutrition. 2003 Mar;19(3):244-9.

12. Dorgan JF, Sowell A, Swanson CA, et al. Relationships of serum carotenoids, retinol, alpha-tocopherol, and selenium with breast cancer risk: results from a prospective study in Columbia, Missouri (United States). Cancer Causes Control 1998;9(1):89-97.

13. Edwards AJ, Vinyard BT, Wiley ER, Brown ED, Collins JK, Perkins-Veazie P, Baker RA, Clevidence BA. Consumption of watermelon juice increases plasma concentrations of lycopene and beta-carotene in humans. J Nutr. 2003 Apr;133(4):1043-50.

14. Flood V, Smith W, Wang JJ, Manzi F, Webb K, Mitchell P. Dietary antioxidant intake and incidence of early age-related maculopathy: the Blue Mountains Eye Study. Ophthalmology. 2002 Dec;109(12):2272-8.

15. Franceschi S, Bidoli E, La Vecchia C, et al. Tomatoes and risk of digestive-tract cancers. Int J Cancer 1994;59(2):181-184.

16. Gianetti J, Pedrinelli R, Petrucci R, Lazzerini G, De Caterina M, Bellomo G, DeCaterina R. Inverse association between carotid intima-media thickness and the antioxidant lycopene in atherosclerosis. Am Heart J. 2002 Mar;143(3):467-74.

17. Giovannucci E, Clinton SK. Tomatoes, lycopene, and prostate cancer. Proc Soc Exp Biol Med 1998;218(2):129-139.

18. Giovannucci E. Tomatoes, tomato-based products, lycopene, and cancer: review of the epidemiologic literature. J Natl Cancer Inst 1999; 91(4):317-331.

19. Giovannucci E, Rimm EB, Liu Y, Stampfer MJ, Willett WC. A prospective study of tomato products, lycopene, and prostate cancer risk. J Natl Cancer Inst. 2002 Mar 6;94(5):391-8.

20. Greul AK, Grundmann JU, Heinrich F, Pfitzner I, Bernhardt J, Ambach A, Biesalski HK, Gollnick H. Photoprotection of UV-irradiated human skin: an antioxidative combination of vitamins E and C, carotenoids, selenium and proanthocyanidins. Skin Pharmacol Appl Skin Physiol. 2002 Sep-Oct;15(5):307-15.

21. Gross M, Yu X, Hannan P, Prouty C, Jacobs DR Jr. Lipid standardization of serum fat-soluble antioxidant concentrations: the YALTA study. Am J Clin Nutr. 2003 Feb;77(2):458-66.

22. Hadley CW, Clinton SK, Schwartz SJ. The consumption of processed tomato products enhances plasma lycopene concentrations in association with a reduced lipoprotein sensitivity to oxidative damage. J Nutr. 2003 Mar;133(3):727-32.

23. Hak AE, Stampfer MJ, Campos H, Sesso HD, Gaziano JM, Willett W, Ma J. Plasma carotenoids and tocopherols and risk of myocardial infarction in a low-risk population of US male physicians. Circulation. 2003 Aug 19;108(7):802-7. Epub 2003 Aug 04. Comment in: Circulation. 2003 Aug 19;108(7):e9012-3.

24. Heinrich U, Gartner C, Wiebusch M, Eichler O, Sies H, Tronnier H, Stahl W. Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema. J Nutr. 2003 Jan;133(1):98-101.

25. Holick CN, Michaud DS, Stolzenberg-Solomon R, Mayne ST, Pietinen P, Taylor PR, Virtamo J, Albanes D. Dietary carotenoids, serum beta-carotene, and retinol and risk of lung cancer in the alpha-tocopherol, beta-carotene cohort study. Am J Epidemiol. 2002 Sep 15;156(6):536-47.

26. Huang HY, Alberg AJ, Norkus EP, Hoffman SC, Comstock GW, Helzlsouer KJ. Prospective study of antioxidant micronutrients in the blood and the risk of developing prostate cancer. Am J Epidemiol. 2003 Feb 15;157(4):335-44.Erratum in: Am J Epidemiol. 2003 Jun 15;157(12):1126.

27. Hughes DA, Wright AJ, Finglas PM, et al. Comparison of effects of beta-carotene and lycopene supplementation on the expression of functionally associated molecules on human monocytes. Biochem Soc Transactions 1997;25(2):206S.

28. Neuman I, Nahum H, Ben Amotz A. Reduction of exercise-induced asthma oxidative stress by lycopene, a natural antioxidant. Allergy 2000;55(12):1184-1189.

29. Porrini M, Riso P. Lymphocyte lycopene concentration and DNA protection from oxidative damage is increased in women after a short period of tomato consumption. J Nutr 2000;130(2):189-192.

30. Schmidt R, Hayn M, Reinhart B, et al. Plasma antioxidants and cognitive performance in middle-aged and older adults: results of the Austrian Stroke Prevention Study. J Am Geriatr Soc 1998;46(11):1407-1410.

31. Simon MS, Djuric Z, Dunn B, et al. An evaluation of plasma antioxidant levels and the risk of Breast Cancer: A Pilot Case Control Study. Breast J 2000;6(6):388-395.

32. Smith-Warner SA, Elmer PJ, Tharp TM, et al. Increasing vegetable and fruit intake: randomized intervention and monitoring in an at-risk population. Cancer Epidemiol Biomarkers Prev 2000;9(3):307-317.

33. Steinberg FM, Chait A. Antioxidant vitamin supplementation and lipid peroxidation in smokers. Am J Clin Nutr 1998;68(2):319-327.

34. Sutherland WH, Walker RJ, De Jong SA, et al. Supplementation with tomato juice increases plasma lycopene but does not alter susceptibility to oxidation of low-density lipoproteins from renal transplant recipients. Clin Nephrol 1999;52(1):30-36.

35. Vogel S, Contois JH, Tucker KL, et al. Plasma retinol and plasma and lipoprotein tocopherol and carotenoid concentrations in healthy elderly participants of the Framingham Heart Study. Am J Clin Nutr 1997;66(4):950-958.

36. Watzl B, Bub A, Blockhaus M, et al. Prolonged tomato juice consumption has no effect on cell-mediated immunity of well-nourished elderly men and women. J Nutr 2000;130(7):1719-1723.

37. Wright AJ, Hughes DA, Bailey AL, et al. Beta-carotene and lycopene, but not lutein, supplementation changes the plasma fatty acid profile of healthy male non-smokers. J Lab Clin Med 1999;134(6):592-598.

January 01, 2004