A diet rich in tomatoes (including in pizza) reduced the risk of developing prostate cancer by up to 45% a Harvard study suggested. Tomatoes contain lycopene, for which other studies have claimed anti-cancer properties.

A separate study from the University of Kentucky found that elderly women with low lycopene levels were four times as likely to need help looking after themselves as those with normal levels.

The beneficial effects of the substance which makes tomatoes red, lycopene, has been shown many times. A small case-controlled study* suggested that an over-the-counter supplement, Lyc-o-Mato, protected and acted against prostate cancer.

Twenty-six prostate cancer patients were given either the lycopene supplement or a placebo twice a day for three weeks before their prostate operation. When analysed, the tumours from the men who had taken Lyc-o-Mato were smaller, and less likely to have spread.

The results need confirmation by a larger study.