Lycopene and Prostate Cancer
There are research studies published in scientific journals that investigate the effects of lycopene on various cancer cells in culture or in animal models. Laboratory experiments showed that lycopene slows the growth of tumors in the brain and breast tissues of laboratory animals. Further studies are needed to know whether tumor growth inhibition of lycopene applies in human.
Research funding has been directed on studies investigating the relationship of lycopene and prostate cancer incidence among men. The findings of these studies are inconclusive and contradict each other.
Studies performed in a male population found that consumption of tomatoes and tomato-based products was correlated with a low incidence of prostate cancer in the population. However, a study in 2004 reported that tomatoes have weak protective effects against prostate cancer.
One study reported that lycopene supplements reduce the rapid growth of tumor in a small group of men with prostate cancer. However, another study reported that lycopene supplements do not significantly reduce the growth rate of prostate tumor among men that did not receive hormone therapy. These findings imply that hormone therapy may be responsible in suppressing the growth of tumor and lycopene has no inhibitory effect at all. It may also be possible that lycopene works best in the presence of the hormone.
In 2007, researchers from the National Cancer Institute and Fred Hutchinson Cancer Research Center conducted a study to investigate whether the blood lycopene levels of men that developed prostate cancer differed significantly with the blood lycopene level of men that didn’t developed prostate cancer. The sample size of the study was 28,000 men aged 55-74. The researchers were very frustrated when they learned that there is no significant difference in the blood lycopene levels between healthy men and the men who later on developed prostate cancer.
Prostate cancer is the second leading cause of death among males in the United States. It is not surprising that the researchers showed frustration when they found out that cheap and readily available tomatoes and tomato-products could not effectively protect men from prostate cancer.