A US study has found a link between lung cancer and eating a diet with a high glycaemic index (GI), a measure of carbohydrate content.

The study, conducted for The Daily Mail newspaper, included more than 4,000 white people from Texas – some newly diagnosed with lung cancer and some healthy, as controls.

The researchers assessed their diet to look at whether there was any link between their diagnosis and their intake of high-GI foods, such as white bread, potatoes and rice. Researchers found people in the highest intake group for high-GI foods were about 49% more likely to have lung cancer than someone in the lowest intake group.

But this study is difficult to draw firm conclusions from, as it was a cross-sectional assessment of diet in people who had already been diagnosed with lung cancer – there is no way of knowing whether this is a reliable indication of lifetime dietary patterns, so cause and effect cannot be proved.

Needs further investigation

Overall, the study concluded that the possible link between carbohydrates and lung cancer needed further investigation to see whether there was a direct link, and, if there was, the possible cause needed investigation.

The NHS posted an article in reaction to the study which said: “On its own, this study does not provide strong evidence that ‘carbs are the new cigarettes’.”