Men who follow a vegan diet may cut their risk of prostate cancer, research suggests.
A study found a 35 per cent lower risk of the cancer for those who followed a vegan diet, which is based on plants and includes vegetables, grains, nuts and fruits.
Vegans avoid food that comes from animals, including dairy products, meat and eggs.
The research, funded by the World Cancer Research Fund (WCRF), comes as a separate study suggests men who have radiotherapy to treat prostate cancer could be at risk of secondary cancers of the bladder, bowel area and rectum.
The WCRF study examined data for more than 26,000 men and looked at the relationship between prostate cancer, meat-eating, fish-based diets and vegan diets.
In total, 1079 cases of prostate cancer were identified among the group. About eight per cent of the men studied said they followed a vegan diet.
Researchers from Loma Linda University in California found men who followed a vegan diet had a "statistically significant protective association", with a 35 per cent reduced risk of developing the disease.
Professor Gary Fraser, who led the study, said: "This new research makes a significant step in linking a vegan diet to reduced prostate cancer risk.
"What we now need is more research into this area to determine to the extent a vegan diet could reduce the number of men developing this cancer."
Prostate cancer is the most common cancer in men in the UK, with more than 47,000 new cases each year.
More than 10,000 men die of prostate cancer each year.
In the second study, published in the British Medical Journal, researchers said they had found a possible link between radiotherapy for prostate cancer and an increased risk of developing secondary cancers of the bladder, colorectal tract and rectum.
But they said the absolute rates of these secondary cancers remained very low.
Experts in Canada and the US analysed the results of 21 studies looking at a possible link.
They found an increased risk of cancers of the bladder, colorectum, and rectum, but not cancers of the lung or blood system, after radiotherapy compared with patients having no radiotherapy or surgery.
In an accompanying editorial, Christine Eyler and Anthony Zietman from the Harvard Radiation Oncology Programme in Boston, said concern about secondary cancers "should not stand in the way of an effective and well-studied treatment being given to men with higher grade, lethal prostate cancer for whom the potential benefit simply dwarfs the risk."
Originally published as Vegan diet cuts prostate cancer risk:study