A component of tomato sauce may help reduce DNA damage in the prostate, a new study suggests. This may have implications for the prevention or treatment of prostate cancer. The active ingredient appears to be lycopene, an antioxidant found in large amounts in tomatoes.
Men with prostate cancer who consumed one tomato sauce-based pasta dish a day for 3 weeks had a statistically significant decrease in the amount of DNA damage in their white blood cells and prostate tissues.
The pasta treatments also led to a reduction in their blood levels of prostate-specific antigen (PSA), a protein used to assess prostate cancer risk, report Longwen Chen M.D., Ph.D., Phyllis Bowen, Ph.D., R.D., and their colleagues at the University of Illinois at Chicago. The findings appear in the Dec. 19 issue of the Journal of the National Cancer Institute.
Human prostate tissue may be particularly vulnerable to oxidative DNA damage caused by free radicals, and an accumulation of this damage may play a role in the development of prostate cancer.
Antioxidants such as lycopene can help remove free radicals. Tomatoes are especially rich in lycopene. In past epidemiologic studies, men who reported eating more tomato-based foods had a lower risk for prostate cancer - the second leading cause of cancer-related deaths among U.S. men.
In the new study, investigators measured blood leukocyte and prostate lycopene concentration, blood PSA levels, and blood leukocyte DNA damage in 32 men with localised prostate cancer. The subjects then ate one tomato-based pasta dish a day for 3 weeks before their scheduled prostate cancer surgery. Entrees consisted of a three-fourth cup of spaghetti sauce incorporated into four different dishes: sausage lasagne, baked rigatoni, penne pasta, and stuffed shells.
After the 3-week regimen and after surgery, there was an accumulation of lycopene in the prostate tissues and a statistically significant 21.3 per cent decrease in oxidative DNA damage in leukocytes compared with pre-intervention levels. Their prostate DNA damage was 28.3 per cent lower than a control group's. PSA levels decreased 17.5 per cent after the intervention, but the authors note that it is unclear whether lycopene was the cause of the reduction.
The authors note that this answer may come from the results of an ongoing clinical trial involving lycopene and a placebo.