Between them, cauliflower can cut the chances of developing the cancer by 52 per cent, while broccoli can reduce the risk by as much as 45 per cent, say researchers. Although the two vegetables have long been thought to protect against the disease, this is the first study to show they are particularly good at preventing dangerous forms of prostate cancer.
At the same time, this study shows that other fruits and vegetables do not have the same impact.
The findings stemmed from a survey of 29,000 men spanning four years. They were regularly screened for signs of prostate cancer. Researchers also monitored their eating habits, particularly their intake of different vegetables.
The results published in the Journal of the National Cancer Institute also question the cancer-preventing powers of foods such as tomatoes.
In the study, the researchers could notice that the numbers diagnosed with fast-growing tumors likely to spread through the body, were much lower for those who ate broccoli or cauliflower at least once a week. Incidentally, these vegetables are thought to be rich in compounds that protect against damage to DNA.
Almost 32,000 cases of prostate cancer are diagnosed every year in Britain, and 10,000 men die from it which is, more than one an hour.
The risks increase with age; men over 50 more likely to develop a tumor. A strong genetic link exists too.
One of the first signs of prostate cancer can be frequent urination, as the tumor presses on the urethra (the tube that carrying urine out of the body.)
Some prostate tumors are slow-growing and rarely spread to other organs, while others are much more aggressive. The survival rate for patients diagnosed with the latter is poor.
The researchers were quoted: "One way to reduce the burden of this disease may be primary prevention through increased consumption of broccoli and cauliflower."
Cancer Research UK welcomed the findings and said vegetables such as broccoli and cauliflower could also help reduce the risks of different cancers.
The organization is backing a trial, called CRISP-1, to see if a chemical called diindolylmethane that is found in green leafy vegetables can help ward off cervical cancer in women.