'Poor Carb' Diets and Nonsmoker Lung Cancer Risk
Study suggests link for regimens rich in refined carbs, potatoes, but it can't prove cause-and-effect
By EJ Mundell
FRIDAY, March 4, 2016 (HealthDay News) -- Even people who've never smoked can get lung cancer, and a new study suggests their risk for the disease may rise if they eat a diet rich in certain carbohydrates.
These so-called "high glycemic index" diets -- regimens that trigger higher levels of insulin in the blood -- tend to be heavy in refined, "poor quality" carbs, one expert explained.
"The glycemic index and glycemic load are methods to estimate the quality and quantity of dietary carbohydrates," said Dr. Rishi Jain, a medical oncologist at Fox Chase Cancer Center in Philadelphia. "Examples of foods with a high glycemic index include white bread and white potatoes."
Jain explained that as rates of obesity and heart risk factors rise in the United States, so does the number of Americans with "insulin resistance," a precursor to diabetes. And he said insulin-linked disorders, which are often tied to high-glycemic diets, "have been implicated as potential contributors to a variety of chronic conditions, including certain cancers."
Could lung cancer be one of those malignancies? Dr. Xifeng Wu, chair of cancer prevention at the University of Texas MD Anderson Cancer Center in Houston, conducted the new study to help answer that question.
Her team looked at the health and dietary histories of more than 1,900 people with lung cancer and more than 2,400 people without the disease.
The investigators looked specifically at the intake of foods with a high glycemic index, such as the white bread and potatoes cited by Jain.
Overall, people who registered in the top fifth in terms of a high-glycemic diet had a 49 percent greater risk of developing lung cancer versus those in the bottom fifth, Wu's team reported.
But the trend was even stronger when the study focused on people who had never smoked. In that group, those who scored highest in terms of a high-glycemic diet had more than double the odds of lung cancer compared to never-smokers who had the lowest glycemic index scores.
Wu and her colleagues reported their findings March 4 in the journal Cancer Epidemiology, Biomarkers & Prevention.