Men can halve their risk of developing prostate cancer by ensuring their diet is rich in onions, garlic, leeks and scallions.

It was reported in the Metro newspaper that researchers asked 238 Chinese men with the disease, and 471 without, how often they ate 122 types of food.

They found the men who ate more than a third of an ounce a day from the allium food group – which includes onions and its family – had a much lower risk of the disease. While eating a tenth of an ounce of salad onion a day reduced the risk by 70 per cent.