Eating a diet rich in bad carbohydrates can increase risk of lung cancer, according to a new study.

A research team headed by Xifeng Wu at the University of Texas MD Anderson Cancer Center set out to examine the effects of eating a diet that consists of foods with a high glycemic index on lung health. Glycemic index refers to how much and how fast carbohydrates increase the body's blood glucose levels right after eating.

Wu and her colleagues conducted in-person interviews with 1,905 patients who were newly diagnosed with lung cancer and 2,413 people who did not have lung cancer about their dietary intake, which included what they ate, how often they ate and how large their food portions were. The researchers focused on food with a high glycemic index, such as white bread and potatoes.

The researchers found that people who ate diets that ranked at the highest for glycemic index were 49 percent more likely to develop lung cancer in comparison to the participants who ate diets that included foods with the lowest glycemic indexes. The risk for squamous cell lung carcinoma, specifically, was 92 percent greater in people with the highest glycemic index levels.

Additionally, the researchers found that the link between glycemic index and lung cancer was even more pronounced in participants who were not smokers. Non-smokers with high levels of glycemic indexes were 81 percent more likely to develop lung cancer when compared to non-smokers with low glycemic index levels.

"Although smoking is a major, well-characterized risk factor for lung cancer, it does not account for all the variations in lung cancer risk. This study provides additional evidence that diet may independently, and jointly with other risk factors, impact lung cancer etiology," Wu said.

The researchers added that their findings suggest that people can lower their risk of lung cancer by improving their diets.

"Traditionally, glycemic index is only emphasized for diabetes prevention and management. However, if the results from this study are confirmed, health care providers should be made aware of the link between glycemic index and lung cancer so they can communicate with their patients and the public about dietary changes for lung cancer prevention," Wu concluded.

The study was published in the journal Cancer Epidemiology, Biomarkers & Prevention.