Men may be able to lower their risk of developing prostate cancer, or slow its progression, by watching their diets, a new research review suggests.

In an analysis of previous studies, mostly published since the 1990s, Australian researchers found that, in general, diets relatively high in fat, processed or grilled meats, or dairy products were linked to an increased risk of prostate cancer.

In contrast, men who regularly eat their vegetables - in particular, tomatoes and cruciferous vegetables like broccoli, cauliflower, cabbage and Brussels sprouts - seem to have a relatively lower risk of developing the cancer.

The same appears true of men who consume greater amounts of vitamin E, soy, fish and omega-3 fatty acids - “good” fats found in oily fish and certain other foods, such as flaxseeds.

What’s more, the review found, there is evidence that a similar eating pattern may help slow tumor progression in men who have prostate cancer.

The findings appear in the current issue of the Journal of Human Nutrition and Dietetics.

The role of diet in prostate cancer is still not completely clear. Studies on individual foods or nutrients - including dairy, calcium, tomatoes and lycopene - have often come to conflicting confusions.

But while the evidence is “not concrete,” men should be aware that diet may influence their risk of prostate cancer, lead researcher Dr. Robert Ma, of the University of New South Wales in Sydney, told Reuters Health.

On balance, he explained, research suggests that eating grilled or processed meat more than five times per week is associated with a higher risk of prostate cancer. Similarly, men who eat dairy products more than five times per week may have a higher risk than those who consume such foods infrequently.

On the other hand, a diet low in saturated fat, but high in tomatoes, cruciferous vegetables, fish and omega-3 fats may help lower the chances of prostate cancer development or progression.

That said, Ma advised that men with prostate cancer discuss any diet and lifestyle changes with their doctors.

Those hoping to prevent the disease should exercise some caution as well, according to Ma, who pointed out that the review did not look at the effects of excessively high consumption of any nutrients, some of which could be harmful.

Men should be careful about taking high doses of any supplement, he and his colleagues say.

Last year, a large U.S. study found that vitamin E and selenium supplements, together or alone, did not lower men’s chances of developing prostate cancer - and among men on vitamin E alone, there was a slightly higher number of cancer cases, though the link may have been due to chance.

SOURCE: Journal of Human Nutrition and Dietetics, June 2009.