A new study by researchers at Curtin University of Technology shows that eating yellow, orange and red fruits such as tomatoes, watermelon and citrus, and vegetables such as red capsicum or sweet pepper, pumpkin and spinach may reduce the risk of developing prostate cancer by up to 50 per cent.
The study by the School of Public Health's Dr Le Jian, Professor Colin Binns and Associate Professor Andy Lee looked at a total of 404 Chinese subjects - comprising patients who had developed prostate cancer and controls who were not suffering from any cancer. Comparisons were made between the two groups with respect to dietary and lifestyle factors.
According to Professor Binns the study shows the risk of developing prostate cancer was reduced by about half in the men who regularly consumed tomatoes, watermelon, citrus, pumpkin and spinach as compared to those who did not eat much of these sorts of fruits and vegetables.
"We recommend eating more yellow, orange and red vegetables and fruits such as tomatoes, - watermelon, citrus and pumpkin plus dark green vegetables such as spinach because the risk of prostate cancer declines with increased consumption of the lycopene and other carotenoids found in these fruits and vegetables," Professor Binns said.
"Lycopene found in the red colourings in fruit and vegetables is a powerful antioxidant that helps prevent damage to DNA in cells - which is one of the key factors to the development of cancer. Lycopene also slows down the growth of human cancer cells.
"We recommend eating two serves of fruit and five serves of vegetables each day as outlined in the Australian Government's Dietary Guidelines.
"This is the first time such findings have been reported in an Asian population and confirm other studies that have identified lycopene as a protective agent against some types of cancers."
The Curtin study was conducted in Hangzhou, China because of its large population, the relatively stable diet of the older residents and the fact that the incidence of prostate cancer is much lower than that in Australia. The findings were recently published in the International Journal of Cancer.
Prostate cancer is the most common cancer in Australian men and the second leading cause of death among cancers. The prevalence of prostate cancer varies a lot around the world, suggesting that there are factors in diet, lifestyles and environment that might increase the cancer risk or protect against cancer development.