Are carbs the new tobacco?
Carbohydrates, long blamed for fuelling obesity, have now been linked to lung cancer.
A new study has revealed a 49% increase in risk among people consuming a diet with a high glycemic index.
The index measures how quickly blood sugar levels are raised after a meal, and foods with a high GI include white bread or bagels, corn flakes and puffed rice.
However, diets high in fruits and vegetables were found to decrease the risk.
Lead study author Stephanie Melkonian, of University of Texas MD Anderson Cancer Centre, said: "We observed a 49% increased risk of lung cancer among subjects with the highest daily GI compared to those with the lowest daily GI.
"Diets high in glycemic index result in higher levels of blood glucose and insulin, which promote perturbations in the insulin-like growth factors (IGFs).
"Previous research suggests increased levels of IGFs are associated with increased lung cancer risk.
"However, the association between glycemic index and lung cancer risk was unclear."
The study is the largest ever to investigate the potential link between glycemic index and lung cancer.
Senior study author Xifeng Wu said: "The associations were more pronounced among subjects who were never smokers, diagnosed with squamous cell carcinoma or had less than 12 years of education."