Diet and your lung cancer risk

Could your diet be affecting your chances of developing lung cancer? A new study from MD Anderson shows a link between a diet with a high glycemic index and lung cancer risk. The link was especially strong in non-smokers.

The glycemic index is a ranking system that shows how quickly the carbohydrates you eat increase your blood sugar. Foods with a high glycemic index are quickly digested and cause a spike in blood sugar glucose and insulin levels. This can affect cell growth and lead to tumor growth.

“This study shows that living a healthy lifestyle, including cutting back on foods and drinks with a high glycemic index, may help lower a person’s overall lung cancer risk,” says Xifeng Wu, M.D., Ph.D., professor of Epidemiology and senior author of the study.    

Diet is a potential new risk factor for lung cancer

About 80 to 90% of lung cancer cases are caused by smoking. Environmental factors like secondhand smoke and asbestos also have been linked to lung cancer. 

Now researchers are looking at whether diet and other risk factors may increase a person’s lung cancer risk. This new research is the largest study on links between glycemic index and lung cancer. The study surveyed the dietary habits and health histories of 1,905 lung cancer patients and 2,413 healthy individuals. All participants were non-Hispanic whites.

This is the first study to show a significant link between the glycemic index and lung cancer in specific groups of people, such as lifetime non-smokers.

Wu says more research is needed to better understand the link between diet and lung cancer.

Maintain a healthy diet

Specific dietary recommendations can’t be made based on this study. But our experts suggest limiting foods and drinks with a high glycemic index, like white bread and bagels.

“Foods with a high glycemic index tend to be more processed and contain more added sugar,” says Stephanie Melkonian, Ph.D., Epidemiology postdoctoral fellow and lead author of the study. “They’re not quality carbohydrates. They don’t offer a lot of nutrients.”

You don’t need to cut all carbs out of your diet, though. Carbs should make up 45 to 65% of your daily calories, according to the American Institute for Cancer Research.  It’s best to get your carbs from whole grain sources, like brown rice, oats, whole wheat bread, sweet potatoes, corn and peas. That’s because the fiber in whole grains helps you stay full longer and keeps your cholesterol and blood sugar in check. Whole grains also are loaded with vitamins, minerals and plant compounds that help protect your cells from damage that can lead to cancer.

“Ultimately, though, diet is just one factor that affects your cancer risk,” Melkonian says. “What we’re learning is that living a healthy lifestyle is really the important part.”