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Lycopene

 

Lycopene Introduction

Naturally occurring in both fruits and vegetables, lycopene is a member of the carotenoid family of chemical pigments. Carotenoids are the primary pigments responsible for the unique colors found in these nutritiously dense food sources. Other pigments of considerable importance include Beta-Carotene, Lutein, and Zeaxanthin. Lycopene is responsible for the reddish pigments of vegetables, being the main color constituent to tomatoes. This pigment is also responsible for the color found in fruits such as papaya, pink grapefruit, pink guava, and watermelon.

In various laboratory studies, lycopene has been found to possess the most protective effects against free radical damage when compared to the entire family of the aforementioned biological carotenoids. [1] Lycopene acts as an antioxidant within the body and is considered a powerful nutritional accessory in the protection against the toxic effects of both light and oxygen. It serves as a catalyst for the protection and reparation of damage caused by free radicals upon numerous cellular membranes throughout the human body. Free radicals are agreed upon by leading health experts to be the prime cause of serious diseases including; cancer, blocking of the arteries (atherosclerosis), aging (associated with age related joint deterioration), and nervous system degradation.

Lycopene Food Sources

More than 80% of dietary lycopene obtained daily in the United States results from the consumption of tomato-based products. Lycopene containing fruits also contribute to this consumption percentage. Studies theorize that approximately 25 milligrams of this antioxidant is consumed in the typical American diet per day.

The amount of lycopene contained in a given fruit or vegetable greatly varies and often depends on the type, and ripeness of the food source. Lycopene appears to be quite stable during the processing of foods, and its bioavailablity is considerably influenced by heat and lipid consumption. This supports scientific findings that lycopene is more abundant and accessible in cooked and processed foods (primarily tomatoes) than from the raw variety. [2]

Most popular sources of dietary lycopene include:

Foods:Lycopene content (exp. In micrograms per gram of net weight):
Fresh tomatoes 8.8 – 42.0
Cooked tomatoes 37.0
Tomato sauce 62
Tomato paste 54.0 – 1,500.0
Tomato powder 1,126.0 – 1,265.0
Tomato soup 80.0
Tomato juice 50.0 – 116.0
Pizza sauce 127.0
Ketchup 99.0 – 134.0
Watermelon 23.0 – 72.0
Pink guava 54.0
Pink grapefruit 34.0
Papaya 20.0 – 53.0

Lycopene Uses

The majority of clinical applications on lycopene supplementation are largely based upon its ability to protect cells against oxidative damage. Several studies have indicated that lycopene may harness anticancer benefit. In particular, a recent case-controlled study highlighted a 50% reduction in the occurrence of specific digestive cancers from individuals who increased tomato consumption, as opposed to persons who did not include tomatoes in their diets. [3] Prostate cancer patients may also benefit from the addition of lycopene into diet via direct food sources or dietary supplementation.

Lycopene is a nutrient easily absorbed in the testes, adrenal, and prostate glands. Clinical application suggests that tomato-based food consumption and proper lycopene supplementation may be in direct correlation to the building of resistance in the development of cancer of the prostate. [4, 5] Men who include lycopene in their diets have the lowest risk of developing this type of cancer. A reduction of up to 35% has been observed in clinical study in men who consumed greater than 10 servings of tomato products per week.

Adequate intakes of lycopene have also been reported to reduce the risk of colon, bladder, and breast cancers. [6, 7] Clinical trials of lycopene have been done in these patients to determine its antioxidative effects regarding the development, growth, and size of tumors. Although initial results from diverse studies have been promising, the majority of this research has proven inconclusive. Nonetheless, nutritional scientists agree that by increasing one’s tomato and lycopene intake, one ultimately reduces the occurrence of development and death from certain forms of cancers. [2]

Lycopene has also been proven to inhibit cholesterol synthesis, thereby decreasing the risk for associated diseases resulting from increased LDL plasma levels of cholesterol. [8] Excessive cholesterol levels increase the risk of developing conditions of the heart, primarily coronary artery disease and atherosclerosis. Epidemiological evidence has reported a converse relationship between blood serum levels of lycopene and the risk in developing this disease. [9]

In vitro studies suggest that lycopene may lessen the overall risk factors for the development of cardiovascular disease. In addition, lower lycopene levels in the fatty (adipose) tissue of, primarily, men may be an solid indicator of a risk of a heart attack. [10] Men with higher deposits of lycopene in adipose tissue show a decreased risk for myocardial infarction.

Although unsubstantiated, supplemental lycopene may also be effective in the management of HIV disease and other immunological dysfunctions. [11] This may be due to recent findings, which suggest that lycopene may act as an effective immunomodulator.

Initial studies confirm lycopene’s legitimacy in the treatment of diverse and chronic conditions. Today, lycopene research continues and studies are exploring this carotenoid’s role in various conditions such as skin cancer and macular degeneration.

Lycopene Dosages

The most advantageous dosage for lycopene is debatable, and requires further clinical study. There is not an established Recommended Dietary Allowance (RDA) of this nutrient because it is considered nonessential in human physiology. The most common dosages of supplemental lycopene typically range from 5 - 15 milligrams daily.

Lycopene is available for supplemental use in the form of oleoresin, or a preparation consisting of lycopene and phospholipid complexes in oils. These lipids are usually of the medium chain tryglyceride variety. Nutritional supplements vary in amount per serving, but regularly offer dosages ranging from 5 - 10 milligrams.

Form of supplemental lycopene:Average dosages:
Most popular forms include capsules, tablets, and soft gels Dosages ranging from 5 – 15 milligrams per day are usually well tolerated

Lycopene Side Effects and Interactions

There are no known toxicities associated with the supplementation of lycopene. Lycopene supplements are considered safe when used in accordance with the accompanying dosage guidelines supplied by various lycopene manufacturers. Lycopene, as with any dietary supplement, is contraindicated to those who have an underlying hypersensitivity to lycopene containing foods.

A deficiency of lycopene may be correlated to an elevated risk of developing certain eye disorders, like macular degeneration. [12] More research is necessary to determine the actual occurrence and probability of lycopene deficiencies.

Possible drug interactions include: Cholestyramine, Colestipol, Mineral Oils, and Orlistat.

References

1. DiMascio P, Kaiser S, Sies H. Lycopene as the most effective biological carotenoid singlet oxygen quencher. Arch Biochem Biophys 1989; 274:532-8.

2. Gartner C, Stahl W, Sies H: lycopene is more biovailable from tomato paste than from fresh tomatoes. Am J Clin Nutr 1997; 66:116-22.

3. Franceschi S, Bidoli E, LaVeccia C, Talamini R, D’Avanzo B, Negri E. Tomatoes and risk of digestive-tract cancers. Int J Cancer 1994; 59:181-4.

4. Rao AV, Fleshner N, Agarwal S. Serum and tissue lycopene biomarkers of oxidation in prostate cancer patients: a case-control study. Nutr Cancer. 1999; 33:159-164.

5. Kucuk O, Sarkar FH, Sakr W, et al. Phase II randomized clinical trial of lycopene supplementation before radical prostatectomy. Cancer Epidemiol Biomarkers Prev. Aug 2001; 10(8):861-8.

6. Helzlsouer KJ, Comstock GW, Morris JS. Selenium, lycopene, (-tocopherol, (-carotene, retinal, and subsequent bladder cancer. Cancer Res 1989; 49:6144-8.

7. Dorgan JF, Sowell A, Swanson CA, Potischman N, Miller R, Schussler N, Stephenson HEJr. Relationship of serum carotenoids, retinal, (-tocopherol, and selenium with breast cancer risk: results from prospective study in Columbia, Missouri (United States). Cancer Causes Control 1998; 9:89-97.

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

9. Arab L, Steck S. Lycopene and cardiovascular disease. Am J Clin Nutr. 2000; 71(suppl); 1691S-1695S.

10. Kohlmeir L, Lark JD, Gomez-Gracia E, Martin BC, Steck SE, Kardinaal AFM, Ringstad J, Thamm M, Masaev V, Riemersma R, Martin-Moreno JM, Huttunen JK, Kok FJ. Lycopene and myocardial infarction risk in the EURAMIC study. Am J Epidemiol 1997; 146:618-626.

11. Chew BP. Antioxidant vitamins affect food animal immunity and health. J Nutr. Jun1995;125(6 Suppl):1804S-1808S.

12. Mares-Perlman JA, et al. Serum Antioxidants and Age-related Macular Degeneration in a Population-based Case-control Study. Arch Ophthalmol. Dec 1995;113(12):1518-1523.