THE humble tomato could become a potent weapon in the fight against prostate cancer.

A number of studies have suggested that lycopene - a powerful antioxidant in tomatoes - could reduce a man's chance of developing the disease.

And cancer charities believe that tomatoes and tomato-based products should play a prominent part in a varied and healthy diet.

The advice comes as research has revealed that a Mediterranean- style diet, which is rich in fresh vegetables and olive oils, is better for health than a typical Western diet.

Dr Ian Lewis, Tenovus's scientific officer, said, "Many people believe that getting cancer is purely down to chance, but around a half of all cancers could be prevented if people made healthier lifestyle choices.

"Tenovus supplies many kinds of prevention advice and information brochures as well as funding important genetic research work which helps determine the likelihood of certain cancers. Increasingly, scientists are showing that a healthy, balanced diet is an important factor in the prevention of cancer. Tomatoes are high in content of a substance called lycopene which is found in many red fruits and vegetables. Although not fully understood as yet, it is thought that lycopene has a protective effect against prostate cancer when consumed as part of a healthy diet.

"Roasting tomatoes is thought to release the health benefits of the lycopene even further and tomato ketchup acts like a shot of lycopenes as the tomatoes have been concentrated."

Increasing numbers of men are being diagnosed with prostate cancer in Wales - it is not yet clear whether this is due to increased awareness and the popularity of the PSA test, or whether it reflects a growing prevalence.

Cases of the disease in Wales rose by 38.9% between 2000 and 2004, from 1,647 to 2,288, according to figures from the Welsh Cancer Intelligence and Surveillance Unit.

Dr Chris Hiley, head of policy and research for the Prostate Cancer Charity, said, "Lycopene is a powerful antioxidant found in tomatoes, which may reduce the chance of prostate cancer developing.

"Processed tomatoes, especially tomato sauce, are particularly rich in lycopene. It is also found in other red fruits and vegetables, for example strawberries.

"Over recent years prostate cancer researchers have repeatedly returned to questions about the role of the antioxidant lycopene in diet - particularly from tomato-based products - in light of its apparent association with a reduced risk of prostate cancer.

"Not all studies are positive, but many are. We still cannot come to a firm conclusion that the risk of prostate cancer is reduced by increasing lycopene intake, but it is very clear that men should eat a varied and healthy diet, and tomato and tomato-based products have a place in that.

"We also advise men to eat a diet containing plenty of fruit and vegetables, to reduce their intake of animal fat, particularly red meat and, of course, keep their weight under control."

The advice about tomatoes and lycopene comes after new evidence from the French research institute Inserm found that eating a Mediterranean diet halves the risk of serious lung diseases like emphysema and chronic bronchitis in comparison with those eating a more traditional Western diet.

Dr Paul Walker, chair of PHA Cymru, the Welsh Public Health Association, said, "We have known for many years that such a diet promotes cardiovascular health and reduces the risks of heart attacks, strokes and peripheral vascular disease and probably reduces the risks of certain cancers and of developing Alzheimer's disease, but its protective impact on chronic respiratory disease is a recent finding.

"By the year 2020 it is estimated that chronic respiratory disease will be the world's third leading cause of premature death so the implications of this new finding are truly global.

"It is not clear yet whether the protective effect of the Mediterranean diet for chronic respiratory disease is due solely to its high content of antioxidants which are known to reduce the risk of tissue inflammation, or whether the lower levels of sugars and nitrates in such a diet also contribute."

A factsheet on prostate cancer and diet is available from the Prostate Cancer Charity at www.prostate-cancer.org.uk