An increased intake of green leafy vegetables may reduce the risk of lung cancer by 50 per cent, according to a new study from Spain.

A diet higher in potatoes, cabbage, turnip tops and lettuce was also found to boost protection, according to Galician researchers in the journal Nutrition.

The protective effect of the veg was possibly due to content of certain antioxidants, as well as vitamins A and C and flavonoids.

The study, led by Olga Dosil-Diaz from the Galician Public Foundation for Health Emergencies, analysed 617 people, 295 of whom suffered from lung cancer and 322 of whom were healthy.

But the research found no beneficial link between increased fruit intake and a reduction in the risk of developing lung cancer, which the researchers attributed to the lower vitamin A content of fruit, which is around 10 to 100 times lower than that of green leafy veg and other vegetables.