Lycopene as a dietary supplement
Lycopene is a natural antioxidant primarily found in tomatoes and pink grapefruit, and is recognized for its distinctive red pigment. As a dietary supplement, lycopene is associated with various potential health benefits, although it is not classified as a necessary nutrient. It is believed to be about twice as potent as beta-carotene in its antioxidant properties. Lycopene has been studied for its possible roles in cancer prevention, cardiovascular health, and conditions such as cataracts, gingivitis, and preeclampsia. Research suggests that it may be best absorbed when consumed with dietary fats, though some studies report mixed results on this. While the optimum dosage remains undetermined, studies indicate that amounts between four to eight milligrams daily may be beneficial. Most researchers consider lycopene to be safe, including for pregnant women, although individuals with specific health concerns should consult a healthcare provider before starting supplementation. Overall, while evidence is emerging regarding the various therapeutic uses of lycopene, further clinical studies are necessary to establish definitive health benefits.
Lycopene as a dietary supplement
DEFINITION: Natural substance promoted as a dietary supplement for specific health benefits.
PRINCIPAL PROPOSED USES: None
OTHER PROPOSED USES: Cancer prevention and treatment, cataracts, exercise-induced asthma, gingivitis, heart disease, high blood pressure, intrauterine growth retardation, leukoplakia, macular degeneration, male infertility, oral submucous fibrosis, preeclampsia, general health benefits
Overview
Lycopene is a powerful antioxidant found in tomatoes and pink grapefruit. Like the better-known supplement beta-carotene, lycopene belongs to the family of chemicals known as carotenoids. As an antioxidant, it is about twice as powerful as beta-carotene.
Sources
Lycopene is not a necessary nutrient. However, like other substances found in fruits and vegetables, it may be important for optimal health.
Tomatoes are the best source of lycopene. Cooking does not destroy lycopene, so pizza sauce is just as good as a fresh tomato. Some studies indicate that cooking tomatoes in oil may provide lycopene in a way that is better used by the body, although not all studies agree. Lycopene is also found in watermelon, guava, and pink grapefruit. Synthetic lycopene is also available and appears to be as well absorbed as natural-source lycopene.
Therapeutic Dosages
The optimum dosage for lycopene has not been established, but the amount found helpful in studies generally fell in the range of four to eight milligrams (mg) daily. It has been suggested that lycopene is better absorbed when it is taken with fats such as olive oil, but one study failed to find any meaningful change in absorption.
Therapeutic Uses
Some studies suggest that foods containing lycopene may help prevent macular degeneration, cataracts, cardiovascular disease, and cancer. Only double-blind studies can determine the effectiveness of medical treatments, and, in the twenty-first century, some have been performed that relate to these potential uses of lycopene.
One study of lycopene evaluated its possible benefits for pregnant women. Participants in this double-blind study of 251 women received either a placebo or two mg of lycopene twice daily. For reasons that are not clear, the use of lycopene appeared to reduce the risk of preeclampsia, a dangerous complication of pregnancy. In addition, the use of lycopene appeared to help prevent inadequate growth of the fetus. However, despite these promising results, researchers are cautious about drawing conclusions: several other nutritional substances have shown promise for preventing preeclampsia in preliminary trials, only to fail when larger and more definitive studies were done.
Lycopene has also shown promise for leukoplakia, a precancerous condition of the mouth and other mucous membranes. In a double-blind, placebo-controlled study, fifty-eight people with oral leukoplakia received either eight mg oral of lycopene daily, four mg daily, or placebo capsules for three months. Participants were then followed for an additional two months. The results indicated that lycopene in either dose was more effective than placebo for reducing signs and symptoms of leukoplakia and that eight milligram daily was more effective than four milligram.
Lycopene (taken at a dose of sixteen grams daily) has shown promise for oral submucous fibrosis, a severe condition of the mouth primarily associated with excessive chewing of betel nuts. Regarding yet another mouth condition, gingivitis (periodontal disease), the results of a small double-blind trial suggest that lycopene can offer benefits when taken on its own or when used to augment the effectiveness of standard care.
Evidence hints that lycopene or a standardized tomato extract containing lycopene might be helpful for treating a number of conditions, including prostate cancer, hypertension, breast cancer, and male infertility, and for preventing heart disease, sunburn, and testicular damage caused by the cancer chemotherapy drug adriamycin. Weak evidence hints that lycopene might help protect against side effects, specifically damage to the heart and to developing sperm cells, caused by the drug doxorubicin. Results of studies have been inconsistent regarding the effects of lycopene and exercise-induced asthma.
As the twenty-first century progressed, more clinical studies on lycopene offered clearer results on its health benefits. A study published in 2020 indicated lycopene may help maintain bone health by affecting bone metabolism. This study, however, was performed in vitro, so more investigation was necessary. Studies also showed a clear correlation between supplementation with lycopene and reduced rates of prostate cancer. This was believed to be due to lycopene’s antioxidant powers. Finally, clearer evidence emerged of lycopene’s potential to fight the symptoms of metabolic disease, including high blood pressure, high blood sugar, and high cholesterol.
Safety Issues
Lycopene is believed to be a safe supplement, as evidenced by researchers feeling comfortable giving it to pregnant women. One evaluation of the literature concluded that the long-term use of lycopene should be generally safe in doses up to seventy-five mg per day. Pregnant women should consult with a physician before taking any herbs or supplements. Maximum safe dosages for young children, pregnant or nursing women, and those with severe liver or kidney disease have not been established.
Bibliography
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Engelhard, Y. N., et al. “Natural Antioxidants from Tomato Extract Reduce Blood Pressure in Patients with Grade-1 Hypertension.” American Heart Journal 151 (2006): 100.
Falk, B., et al. “Effect of Lycopene Supplementation on Lung Function After Exercise in Young Athletes Who Complain of Exercise-Induced Bronchoconstriction Symptoms.” Annals of Allergy, Asthma, and Immunology 94 (2005): 480-485.
Sesso, H. D., J. E. Buring, et al. “Plasma Lycopene, Other Carotenoids, and Retinol and the Risk of Cardiovascular Disease in Men.” American Journal of Clinical Nutrition 81 (2005): 990-997.
Sesso, H. D., S. Liu, et al. “Dietary Lycopene, Tomato-Based Food Products, and Cardiovascular Disease in Women.” Journal of Nutrition 133 (2003): 2336-2341.
Shafe, Mercy O., et al. "Lycopene: A Potent Antioxidant with Multiple Health Benefits." Journal of Nutrition and Metabolism, 2024. Wiley Online Library, doi.org/10.1155/2024/6252426. Accessed 20 Sept. 2024.
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Singh, M., et al. “Efficacy of Oral Lycopene in the Treatment of Oral Leukoplakia.” Oral Oncology 40 (2004): 591-596.
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Wang, L., et al. “The Consumption of Lycopene and Tomato-Based Food Products Is Not Associated with the Risk of Type 2 Diabetes in Women.” Journal of Nutrition 136 (2006): 620-625.