Christine McGourty on the benefits of processed tomato

Two major studies suggest that lycopene - a natural pigment that gives tomatoes their red colour and is found in high concentrations in processed products such as tomato ketchup, tomato soup, puree and pizza - is good for your health.

The research indicates that a lycopene-rich diet can reduce the risk of heart disease and prostate cancer.

Further research is also under way to find out whether lycopene can have a positive effect on breast, cervical, endometrial and lung cancer.

Medical experts from Britain and the USA are meeting at the Royal Society of Medicine in London on Thursday for a one-day seminar called "Tomatoes - Lycopene and Health" to review the latest findings.

Lycopene in fresh tomatoes is less easy to digest

A six-year study of 48,000 male health professionals, conducted by Harvard Medical School in 1995, found that consuming tomato products more than twice a week, as opposed to never, reduced the risk of prostate cancer by up to 34%.

Tomato sauce is best

Of the tomato-based products, the link was greatest for tomato sauce followed by canned tomatoes and pizza, with little or no benefit being found from tomato juice. Lycopene present in fresh tomatoes is less easy to digest.

Another study by the University of North Carolina published in 1997 - which compared 1,379 American and European men who had suffered a heart attack with the same number of healthy men - found that the risk of another heart attack was halved for those with high levels of lycopene.

Dr Nigel Dickie, director of the newly established Lycopene Project, funded by ketchup and soup makers Heinz, said: "It's often supposed that fresh vegetables are nutritionally superior to processed.