If you’re not a smoker, you might think lung cancer isn’t something that could affect you. But as we learn more about the intricacies of cancer, we’re seeing that lung cancer is more complex than that. There is a connection between the glycemic index and lung cancer.
In a study published this month in the journal Cancer Epidemiology, Biomarkers & Prevention, researchers examined the link between the glycemic index and lung cancer. They found that people who eat a diet heavy in high-glycemic index foods like white bread, white-flour pasta, refined cereal and instant oatmeal had a 49 percent higher risk of developing lung cancer.
This increased risk existed in non-smokers as well as smokers. One interesting takeaway from the study was that the quantity of carbohydrates (glycemic load) didn’t have a correlation — meaning it’s all about the specific carbohydrate choices we make.
So, what does the glycemic index have to do with lung cancer?
The link lies in insulin resistance.
First a bit of background on the process of how food and insulin works. Glycemic index tells how quickly a carbohydrate increases blood glucose levels, also called blood sugar levels. As your blood glucose increases, your pancreas produces insulin which helps cells absorb the glucose and use it for energy.
Insulin resistance occurs when the cells in the body stop responding to insulin. When that happens, glucose builds up in the bloodstream, leading to health problems like diabetes.
But that’s not all. When insulin resistance develops, it also may lead to the activity of certain cellular growth factor chemicals that play a role in cancer development. Previous studies have suggested a possible correlation between high-GI diets and/or insulin resistance and colorectal cancer, breast cancer and prostate cancer.
This new lung cancer study is particularly interesting because the association between a high-GI diet and lung cancer was so pronounced among non-smokers. That said, it’s important to note that these results show only an association — not cause and effect, as the researchers didn’t take into account other illnesses that may cause cancer, such as heart disease, high blood pressure and diabetes.
But even so, this study contributes to the growing body of evidence that poor diet and obesity play a critical role in the development of cancer. As we seek to better understand the mechanisms of cancer, it’s empowering to know that our everyday choices could have a profound impact on cancer prevention.
About the Author
Douglas Reznick, MD, is a board-certified medical oncologist specializing in thoracic (lung), brain, head and neck cancers. After earning his MD from the Sackler School of Medicine, he completed his residency at HealthOne/Presbyterian-St. Luke’s Medical Center and a fellowship at the University of Colorado Health Sciences Center. He actively participates in Rocky Mountain Cancer Center’s clinical trial program and is a member of the Colorado Medical Society.