bagel shop
© Gary Cameron / Reuters

Comment: This is priceless! All the warnings about smoking causing lung cancer, and it turns out that smoking correlates with a decrease risk of lung cancer for those with a diet high in GI foods. One would think this would lead to further investigation and a questioning of the 'risks of smoking', but unfortunately the senior author still recommends avoiding smoking as a way to reduce the risk of lung cancer. Propaganda and belief runs deep.

Eating foods that are high on the glycemic index (GI), such as white bread, bagels, and rice, can increase the risk of lung cancer by as much as 49 percent, a new study has found.

Having examined the eating and smoking habits of 4,320 people, of whom 1,905 were diagnosed with cancer and 2,415 had no health issues, researchers found that those with a diet high in GI foods were nearly 50 percent more likely to develop lung cancer.

What many may find even more surprising, however, is that non-smokers with such a diet are more at-risk, with results showing that they were more than twice as likely to develop the cancer as those with a diet mainly low in GI food.

The study, which was conducted at the University of Texas MD Anderson Cancer Center, found that high GI foods, which also include potatoes and corn flakes, produce high levels of blood glucose and insulin, thus causing an increase in insulin-like growth factors (IGFs) associated with increased lung cancer risk.

Previous research has shown that diets including large quantities of red meat, saturated fats, and dairy products can increase the risk of developing cancer, while diets high in fruits and vegetables may decrease the risk.

"The results from this study suggest that, besides maintaining healthy lifestyles, such as avoiding tobacco, limiting alcohol consumption and being physically active, reducing the consumption of foods and beverages with high glycemic index may serve as a means to lower the risk of lung cancer," said Dr. Xifeng Wu, senior author of the study, which was published in the March edition of the Cancer Epidemiology, Biomarkers & Prevention journal.

The study's authors list some examples of low GI foods, including whole-wheat or pumpernickel bread, rolled or steel-cut oatmeal, and pasta.

Lung cancer is the leading cause of cancer mortality in both the US and UK, although smoking is considered to be the leading cause of that disease.

More than 150,000 people will die from lung cancer in the US in 2016, while more than 1 in 5 cancer deaths in the UK will be caused by lung cancer, according to the American Cancer Society.