Cabbages offering heart to smokers

Eat up your veges - it could be the next best thing to giving up smoking.

Scientists have found that a diet rich in cruciferous vegetables - cabbage, broccoli and brussels sprouts - protects against lung cancer.

However, the protective effect only works in people who have one of two genes shared by half the population. Among those with the genes who ate cabbage or its relatives at least once a week the risk of lung cancer was cut by a third.

The effect was seen only in smokers. Among non-smokers, in whom lung cancer is rare, there was no difference between those who ate cabbage and those who didn't.

Many health claims have been made for cruciferous vegetables, which include watercress, pak choi and cauliflower, and the Chinese love of boiled cabbage is credited with contributing to their longevity.

They contain high concentrations of isothiocyanates which have been shown to prevent lung cancer by increasing the excretion of tobacco-derived toxins.

The level of isothiocyanates in the body is controlled by two genes - GSTM1 and GSTT1 - which determine how quickly they are eliminated. People with inactive forms of the genes GSTM1 (50 per cent of the population) and GSTT1 (20 per cent) have higher levels of isothiocyanates because they do not produce the enzymes that break them down.

In a study of more than 2100 patients with lung cancer who were matched with a similar number of controls, researchers from the International Agency for Research on Cancer in Lyon, France, found that those with the inactive form of the gene GSTM1 had a 33 per cent reduced risk of lung cancer.

Among those with the inactive form of the gene GSTT1, the protective effect was greater with a 37 per cent reduced risk.

In those with both genes, the risk was cut by 72 per cent. But people with the active form of the gene had no protection.

Paul Brennan, who led the research published in the Lancet, said: "These data provide strong evidence for a substantial protective effect of cruciferous vegetable consumption on lung cancer." The study was carried out in six countries in central and eastern Europe with traditionally high consumption of cabbage - Poland, Slovakia, Czech Republic, Romania, Russia and Hungary.

Participants detailed their consumption of 23 different foods of which three were cruciferous vegetables.

Those who ate vegetables at least once a week gained the protective effect from them. Those who ate them less than once a month did not.

The findings accord with those of several smaller studies which have shown a protective effect of cabbage on lung cancer, breast cancer and bowel cancer in people with the inactive form of the genes.

In another study, a faulty gene has been found that greatly increases the risk of breast cancer in women with relatives who have the disease.

Having a defective version of the Chek2 gene doubles a woman's risk of getting breast cancer.

But new research published in the Lancet shows that the gene variant also has a big impact on relatives of carriers, especially when there is a family history of cancer in both breasts.

The lifetime risk for the average woman is 7.9 per cent but for the woman with a relative who has had cancer in both breasts it rises to 23.8 per cent.

Among those with a relative who also had the defective version of the Chek2 gene - about 2 per cent of the 2000 women a year diagnosed with cancer in both breasts - their lifetime risk rises to 58.8 per cent.

- INDEPENDENT