Lycopene is no longer considered a useful dietary tool in the fight against prostate cancer. But, you may have decided to try, anyway. We present what little we know, for you to decide for yourself.
Lycopene is categorized as a carotenoid, a colorful compound found in red fruits and vegetables. It is one of the strongest antioxidants found in nature and is present in high concentrations in tomatoes, tomato products and several other foods. The mechanism by which lycopene exerts a protective effect against prostate cancer is poorly understood. However, we do know that it quenches free radicals, which are harmful molecules that form in the body as a result of oxidation. They are highly reactive and can cause damage to DNA, RNA, lipids and proteins in normal healthy cells. Free radicals are believed to be involved in the development of cancerous cells.
A Phase II Randomized Trial of Lycopene Rich Tomatoe Extract Among Men with PINS A Poster Presentation at the 2012 AACR Meeting Dr. Peter Gann of the University of Illinois at Chicago reported on a randomized phase II trial he conducted using lycopene with men with high grade PINs, thought to be a precursor to the development of prostate cancer. He started the study because there is observational epidemiology evidence, animal models and cell culture experiments that have suggested that lycopene might inhibit the development of prostate cancer. Despite this evidence, Dr. Gann pointed out that prior to his study there was little clinical trial evidence of the effectiveness of lycopene. The trial was a 6 month repeat biopsy trial with men who had PINs. Men were randomly assigned to either a placebo control group or to the investigational group. The investigational group received 30 mg a day of a lycopene supplement. They found that at 6 months, despite a large difference in serum (blood) lycopene concentrations in the investigational group, there was no apparent differences between the two groups. They concluded that lycopene had no effect on cell proliferation or on prostate cancer cell inhibition.
Examples of products containing lycopene include:
High concentrations: Tomatoes and tomato products (sauce, soup, paste, juice and ketchup)
Lower concentrations: Guava juice, fresh watermelon, fresh papaya and dried apricot
Sources of Lycopene
Giovannucci and colleagues studied the dietary lycopene intake of a group of men. They found that men who consumed more than 10 servings of tomatoes and tomato products per week had a 35% lower risk of prostate cancer than men who ate less than 1.5 servings per week. In the same study, the consumption of tomato products also decreased the risk of being diagnosed with advanced or aggressive prostate cancer.
In a study at Wayne State University, a pure tomato extract was given to newly diagnosed prostate cancer patients who had chosen surgery as their primary treatment. The researchers hypothesized that lycopene would affect the prostate cancer between the time of diagnosis and the prostatectomy date. Patients taking the lycopene had smaller tumors at the time of prostatectomy. Even further, 73% of the lycopene treated group had organ-confined prostate cancer versus 18% in the untreated group.
Eat tomatoes and tomato products several times per week. Our recommendation is to eat one to two servings of lycopene-rich foods per day (refer to table for serving sizes). Consuming one to two servings of lycopene-rich foods should give you 30-60 mg of lycopene per day.
Avoid lycopene supplements. Instead obtain lycopene from natural food sources.
Cook tomatoes! When tomatoes are heated during cooking and processing, the lycopene is more available to the body. Processed tomato products, such as juices, pasta sauces, cooked tomatoes and soups are excellent sources of bio-available lycopene.
Do not eat high-fat and high-sodium foods that contain lycopene, such as pizza. Instead choose low-fat foods containing lycopene (such as low-fat tomato sauces).