Eating lots of vegetables and increasing exercise could help men prevent the progression of prostate cancer, a researcher says.

As if prostate cancer were not scary enough, hundreds of men with the disease are being subjected to a menu of raw, bitter vegetables for five years.

That means lots of kale, turnips and radishes to go with their carrots and tomatoes.

This and exercise could help slow the disease, even in its advanced stages, says study leader Dr Kellogg Parsons, a speaker at the Urological Society of Australia and New Zealand Annual Scientific Meeting in Brisbane.

He is studying 464 US men with low-grade prostate cancer for five years to see how the disease progresses if they eat well and exercise regularly.

His previous population-based studies have shown people who regularly eat vegetables significantly reduce their chance of dying from bladder, kidney or prostate cancer.

“This is likely to be the case for all cancers,” said Dr Parsons, an associate professor of urology at the University of California, San Diego.

“People are likely to benefit from eating more vegetables, less fat, less meat, less processed carbohydrates and doing three or four exercise sessions a week.”

Thirty minutes of moderate exercise a day can be beneficial for prostate cancer patients, but research suggests more rigorous exercise is especially beneficial.

Men in his study are encouraged to eat at least seven cups of vegetables a day.

“It’s a lot, so juicing some of the servings could make it easier,” Dr Parsons said.

“Our perspective is that raw vegetables are better than cooked.”