Lycopene Usage

Some but not all observational studies suggest that foods containing lycopene may help prevent macular degeneration , cataracts , cardiovascular disease , and cancer . ¹ However, observational studies are highly unreliable means of determining the effectiveness of medical treatments; only double-blind studies can do so, and few have yet been performed that relate to these potential uses of lycopene. (For more information on why double-blind trials are so important, see Why Does this Database Rely on Double-blind Studies? )

The best study of lycopene thus far evaluated its possible benefits for pregnant women. ² Participants in this double-blind study of 251 women received either placebo or 2 mg of lycopene twice daily. For reasons that are not at all clear, use of lycopene appeared to reduce risk of preeclampsia , a dangerous complication of pregnancy. In addition, 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. ³ Lycopene has also shown promise for leukoplakia , a precancerous condition of the mouth and other mucous membranes. In a double-blind, placebo-controlled study, 58 people with oral leukoplakia received either 8 mg oral lycopene daily, 4 mg daily, or placebo capsules for three months. ⁴ 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 8 mg daily was more effective than 4 mg.

Lycopene (taken at a dose of 16 g daily) has shown promise for oral submucous fibrosis, a severe condition of the mouth primarily associated with excessive chewing of betel nuts. ⁵ Regarding yet another mouth condition, gingivitis (periodontal disease), the results of a small double-blind trial suggest that lycopene can offers benefits when taken on its own, or when used to augment the effectiveness of standard care. ⁶ Much weaker evidence—far too weak to rely upon at all—hints that lycopene or a standardized tomato extract containing lycopene might be helpful for treating a number of conditions, including prostate cancer, ⁷ hypertension , ⁸ breast cancer ⁹ and male infertility , ¹⁰ and for preventing heart disease , ¹¹ sunburn , ¹² and testicular damage caused by the cancer chemotherapy drug adriamycin. ¹³ Weak evidence hints that lycopene might help protect against side-effects caused by the drug doxorubicin , specifically damage to the heart and to developing sperm cells. ^{14 15} Results of studies have been inconsistent regarding the effects of lycopene and exercise-induced asthma . ¹⁶ One observational study failed to find that high consumption of lycopene reduced risk of developing diabetes . ¹⁷