Lycopene, a red pigment that gives tomatoes their distinctive colour, could help prevent prostate cancer, say scientists.
Lycopene is a potent antioxidant and some studies have shown that tomato-rich diets may lower the risk of certain cancers, especially those of the prostate, lung and stomach.
"We're not setting out to treat cancer, but to prevent it, and we're hoping to do so with lycopene," said Richard van Breemen, University of Illinois' professor of medicinal chemistry, who led the study, reports the journalCancer Prevention Research.
Each day, half of the study's 105 participants aged between 50 and 80 years, received two gel capsules containing 30 mg of lycopene, while the other half received placebo capsules that contained only soybean oil.
The lycopene approximated the amount that can be ingested daily by eating foods rich in tomato sauce, such as spaghetti and pizza, van Breemen said.
Researchers wanted to see if lycopene would rise in the blood and prostate tissue, and if it could lower markers of oxidative stress -- a factor in many diseases, such as cancer and Alzheimer's, and in the body's normal aging process.
Oxidative stress injures cells within the body, while antioxidants help cells cope against the damage, van Breemen said.
After receiving lycopene or placebo for three weeks, all subjects underwent needle biopsies to diagnose BPH (enlarged prostate) or prostate cancer. Two additional biopsies were taken to measure lycopene and DNA oxidation, he said.
The pathology indicated that 51 men had prostate cancer while 65 had BPH. Men who received lycopene showed "a significant increase" of the antioxidant in the blood, van Breemen said, compared to the placebo control group.