Study links higher glycemic index diets with increased lung cancer risk

Background: In this study, researchers examined whether people who follow higher-GI or higher-GL diets have different risks of developing lung cancer. They used data from 101,732 adults in the U.S. National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial cohort who filled out a detailed diet questionnaire when they joined the study (1993–2001). These adults were followed for about 12 years to see who developed lung cancer. The researchers then compared people with the highest GI and GL to those with the lowest, accounting for smoking and other factors.

What this study found:

• Glycemic index: People who ate diets with the highest glycemic index had a higher chance of lung cancer than those with the lowest glycemic index - about 13% higher overall - including higher risks for both non–small cell and small cell lung cancer.

• Glycemic load: People who ate diets with the highest glycemic load had a lower chance of lung cancer than those with the lowest glycemic load - about 28% lower overall - and the pattern was similar for non–small cell lung cancer. There was no clear link for small cell lung cancer.

Implications: Diets that contain fewer amounts of high glycemic index foods and higher amounts of high-quality carbohydrates, such as vegetables, fruits, and whole grains, may be linked to lower lung cancer risk.