A diet rich in garlic, onions, shallots, leeks and scallions may cut the risk of prostate cancer. That is according to a new study by researchers at the U.S. National Cancer Institute.

Experts say China has the lowest rate of prostate cancer in the world. And so-called allium foods, including garlic, onions, shallots, leeks and scallions, shown in previous studies to have anti-cancer properties, are a staple of Chinese cooking.

So researchers studied a group of about 200 men with prostate cancer and nearly 500 disease free men in Shanghai, and asked them how often they ate 122 food items, including allium vegetables.

The results: men who ate small amounts of onions, garlic, scallions, shallots and leeks every day appeared to reduce the risk of prostate cancer by more than one-third.

"In our study, consumption of garlic, about two-grams per day, is associated with a 53 (percent) reduction risk of prostate cancer in this population," said Ann Hsing, head of the investigation at NCI.

Investigators found that as little as one clove of garlic per day cut the risk of cancer.

The study also showed that scallions were the most beneficial of the allium foods, lowering the risk of prostate cancer by more than 70 percent.

The study's findings are published in the Journal of the National Cancer Institute.

Ms. Hsing says the results of her study need to be repeated in other studies. She says it is too early to make any recommendations based on her group's findings.

"But I think what it is saying is a healthy diet, a balanced diet, is good and probably will be protective and be associated with a lower risk of cancer," she said.

Experts have long said eating a diet rich in vegetables and fruit is important in maintaining good health.