Joan H. Schiller, MD, is internationally recognized for her work in lung cancer research and is founder and president of Free to Breathe, an advocacy organization dedicated to raising awareness of and funding for lung cancer.
A new study by scientists at The University of Texas MD Anderson Cancer Center has found that certain types of diets are associated with an increased risk of developing lung cancer, especially in people who have never smoked. The finding adds important new clues for preventing and treating the disease.
Glycemic Index: Increasing Cancer Risk
It’s clear that smoking is the biggest cause of lung cancer. Indeed, smoking causes an estimated 80 to 90 percent of all lung cancer cases. Yet people who have never smoked still get lung cancer. The big question is: What’s causing it?
Exposure to radon is one culprit. Radon is a radioactive gas that is naturally present in some areas. Air pollution is another possible cause. Now, we have evidence that certain diets might also increase the risk of lung cancer.
The new research focused on glycemic index (GI), a measure of how quickly carbohydrates elevate blood sugar levels. The study showed that people who consumed high-GI diets had an increased risk of developing lung cancer.
Intriguingly, the link between GI and lung cancer was especially significant among people who had never smoked.
Sugar Fuels Cancer
High-GI foods are those that make a person’s blood sugar spike quickly. Sugary foods and refined carbohydrates such as cakes, cookies, potatoes, white rice and white bread are high on the GI scale, while whole-grain carbohydrates have a lower GI.
The link between sugar and cancer isn’t new. We’ve known for some time that sugar is important to the growth of cancer cells.
In fact, the PET scans that doctors often use to diagnose cancer rely on that principle. In these scans, patients are injected with a sugar solution tagged with radioactive atoms. Cancer cells metabolize, or process, that sugar faster than healthy cells, making tumors light up on the scan.
But this study extends our understanding of sugar and cancer by showing for the first time that diet can increase a person’s risk of developing lung cancer.
Attacking Lung Cancer
This research is exciting for a number of reasons. For one thing, it helps us better understand some of the lifestyle factors that can increase the risk of lung cancer.
Perhaps even more importantly, the research could lead to new ways of attacking lung cancer. If we can learn more about how cancer cells use sugar to fuel their growth, we might be able to block that process and starve the tumors — not only in the lungs, but throughout the body.
Compared to major risk factors, such as smoking, I suspect that a high-GI diet will prove to be a relatively small risk for lung cancer. Still, lower-GI diets are important for preventing diseases, such as diabetes, and promoting overall good health. This study adds yet one more reason to adopt healthier eating habits.