Broccoli May Cut Prostate Cancer Risk
Study Shows Link Between Eating Broccoli and Gene Changes
Why Not Peas?
Broccoli and other cruciferous vegetables have compounds known as glucosinolates. Peas do not.
Glucosinolates convert to other compounds known as isothiocyanates, which are widely believed to have tumor-suppressing activities.
Studies suggest that about half the population carries a gene called GSTM1, which may make these compounds even more protective.
Study participants who expressed the gene showed the most beneficial gene changes after eating broccoli.
But Mithen says the finding does not mean that only 50% of people derive a benefit from broccoli.
"It may mean that people without the gene need to eat a bit more broccoli to get the same benefits," he says. "But the good news is that nobody has to eat huge amounts. A few portions a week seems to make a big difference."
Benefits Not Proven
National Cancer Institute researcher Richard B. Hayes, PhD, says the new research strengthens, but does not prove, the hypothesis that a healthy diet can protect against prostate cancer.
Hayes' own 2007 study suggested a link between a high intake of cruciferous vegetables -- especially broccoli and cauliflower -- and protection from aggressive prostate cancer.
"There is a fairly consistent body of evidence suggesting that fruits and vegetables are protective against many cancers and other diseases," Hayes tells WebMD. "But it may be stretching the point at the moment to say that broccoli prevents prostate cancer."
Hayes says the suggestion that any one compound or group of compounds is responsible for the protective benefits seen in animal and epidemiological studies is premature.
"We can too easily go down that road of looking to develop a pill based on this compound or that compound to protect against cancer, but the truth is we may never find that," he says.