Carbohydrates, long blamed for fuelling obesity, have now been linked to lung cancer. 
 
 A new study has revealed a 49 per cent increase in risk among people consuming a diet with a high glycemic index. 
 
 The index measures how quickly blood sugar levels are raised after a meal, and foods with a high GI include white bread or bagels, corn flakes and puffed rice. 
 
 However, diets high in fruits and vegetables were found to decrease the risk. 
 
 Lead study author Dr Stephanie Melkonian, of University of Texas MD Anderson Cancer Center, said: "We observed a 49 per cent increased risk of lung cancer among subjects with the highest daily GI compared to those with the lowest daily GI. 
 
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 "Diets high in glycemic index result in higher levels of blood glucose and insulin, which promote perturbations in the insulin-like growth factors (IGFs). 
 
 "Previous research suggests increased levels of IGFs are associated with increased lung cancer risk. 
 
 "However, the association between glycemic index and lung cancer risk was unclear." 
 
 In the UK, there are around 45,525 new cases of the disease diagnosed each year, while 35,371 people lose their life to the disease annually, according to Cancer Research UK. 
 
 Photo: Alamy 
 
 In the US, lung cancer is the second most common cancer in both men and women. 
 
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 The study, published in the journal Cancer Epidemiology, Biomarkers & Prevention, is the largest ever to investigate the potential link between glycemic index and lung cancer. 
 
 Scientists surveyed 1,905 patients newly diagnosed with lung cancer and compared the results with 2,413 healthy individuals. 
 
 Senior study author Dr Xifeng Wu said: "The associations were more pronounced among subjects who were never smokers, diagnosed with squamous cell carcinoma or had less than 12 years of education. 
 
 "This suggests that it is the average quality, instead of quantity, of carbohydrates consumed that may modulate lung cancer risk." 
 
 Photo: Alamy 
 
 Dr Wu added: "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." 
 
 • Lung cancer victims lack sympathy ||||| Scientists from the University of Texas MD Anderson Cancer Center have found that people who eat a diet full of high glycemic index foods—think processed white bread, bagels, white rice, baguettes—had a 49% higher risk of developing lung cancer, even if they’ve never smoked a single cigarette. 
 
 The study, which was published in Cancer Epidemiology, Biomarkers & Prevention this week, is the largest ever to investigate the potential links between glycemic index and lung cancer, according to the authors. A glycemic index is a measurement of how rapidly carbohydrates elevate blood sugar levels in the body. The higher the glycemic index, the more rapidly blood sugar levels rise after a meal which results in elevated levels of blood glucose and insulin. That in turns raises what’s called insulin-like growth factors, which are linked to an increased lung cancer risk, according to the scientists. 
 
 Scientists at MD Anderson surveyed 1,905 patients newly diagnosed with lung cancer and another 2,413 healthy individuals, all non-Hispanic whites. Those subjects reported their past dietary habits and health histories, and they were then divided into groups based on their associated glycemic index and glycemic load, a measure of carbohydrate quantity. 
 
 “We observed a 49% increased risk of lung cancer among subjects with the highest daily glycemic index compared to those with the lowest daily glycemic index,” said Xifeng Wu, professor of epidemiology and senior author of the study. “The associates were more pronounced among subjects who were never smokers.” 
 
 Interestingly, there was no link between the glycemic load—i.e. the quantity of carbohydrates consumed—and lung cancer, which suggests that it’s the quality, not the amount of carbohydrates, that has the biggest effect on lung cancer risk, said Wu. 
 
 Lung cancer is the second most common cancer among both men and women in the U.S. It’s also the leading cause of cancer mortality, with over 150,000 deaths from lung cancer expected in the U.S. this year alone, according to the American Cancer Society. Smoking and tobacco use is still the leading cause, though it doesn’t account for all cases. Researchers had long suspected a link between a high-glycemic index diet and lung cancer risk, but the link between the two was unclear until now. 
 
 Among non-smokers in the study, those within the highest glycemic index group were more than twice as likely to develop lung cancer as those in the lowest group. For smokers, the difference was elevated by 31% between the two groups. 
 
 “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 Wu. 
 
 Low glycemic index foods include things like 100% stone-ground whole wheat bread, rolled or steel-cut oatmeal, most fruits, and non-starchy vegetables. ||||| Breaking News Emails Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings. SUBSCRIBE 
 
 People who eat a sugary, starchy diet may be raising their risk of lung cancer, even if they don’t smoke, researchers say. 
 
 They found that people who recall eating more foods that have a high glycemic index also were more likely to develop lung cancer. Glycemic index is a term that’s familiar to people with diabetes. It describes food that raises blood sugar and stimulates production of insulin — think bagels, white rice and some fruits such as melon and pineapple. 
 
 It’s not the first study to link glycemic index with cancer risk, but it’s rare to link it with lung cancer. That may be mostly because lung cancer is so overwhelmingly caused by smoking. 
 
 The team at MD Anderson Cancer Center in Houston studied 1,905 people who had just been diagnosed with lung cancer and compared them to 2,415 people without cancer. They quizzed them about their eating habits, smoking, income and other factors. 
 
 "Reducing the consumption of foods and beverages with high glycemic index may serve as a means to lower the risk of lung cancer." 
 
 People who ate the most foods with a high glycemic index were about 50 percent more likely to be in the lung cancer group than people who reported they ate the fewest high-glycemic foods, the team reported in the journal Cancer Epidemiology and Biomarkers. 
 
 The link was stronger among people who never smoked; non-smokers were more than twice as likely to have lung cancer if they reported eating a high-glycemic diet. 
 
 “The results from this study suggest that, besides maintaining healthy lifestyles, 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, who led the study. 
 
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 How can this happen? Doctors aren’t sure, but there’s a theory that high-glycemic foods stimulate the body to make insulin, which in turn affects the growth of cells via compounds called insulin-like growth factors or IGF. Cancer is the uncontrolled proliferation of cells, so it might be that the high-glycemic foods are fueling the growth of tiny tumors. 
 
 “IGFs have been shown to play a critical role in regulating cell proliferation and differentiation in cancer and there is evidence to suggest that IGFs are elevated in lung cancer patients,” Wu’s team wrote. 
 
 It’s a suspect in several types of cancer. 
 
 “Previous studies have investigated the association between glycemic index, and the related measure glycemic load, and a variety of cancers including colorectal, stomach, pancreas, endometrial, ovarian, prostate, and thyroid but these studies are limited and results have been largely inconclusive,” the researchers wrote. 
 
 This study is not conclusive, either. For one thing, the researchers asked their volunteers to remember what they ate. For another, it’s an association. People who eat high-glycemic foods may also do something else that also raises their risk of cancer. And this particular study focused only on non-Hispanic white people. 
 
 Marji McCullough, an expert in nutritional epidemiology at the American Cancer Society, says it will be important to look at people who don't have cancer now and watch what they eat for years or decades, and see who develops cancer. 
 
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 Lung cancer is the No. 1 cancer killer in the U.S., killing more than 150,000 people a year. It causes only vague symptoms at first, so when most people are diagnosed, the cancer has already spread and is then far more likely to be fatal. 
 
 Experts know diet and lifestyle can affect cancer. Obesity, lack of exercise, eating red meat and lots of high-fat dairy foods, and eating too few fruits and vegetables can all raise a person’s odds of developing cancer. 
 
 This study adds to a growing body of evidence that people can lower their cancer risk not only by staying away from tobacco and exercising more, but by choosing a healthier diet. 
 
 "Aside from not smoking, it’s important to follow cancer prevention guidelines that maintain healthy body weight, physical activity, and eating an overall healthy diet rich in vegetables and plant food and lower red and processed meat. Choose foods that help maintain healthy body weight," McCullough said. 
 
 According to the American Diabetes Association, low-glycemic foods include: 
 
 100 percent stone-ground whole wheat or pumpernickel bread 
 
 Oatmeal (rolled or steel-cut), oat bran, muesli 
 
 Pasta, converted rice, barley, bulgar 
 
 Sweet potato, corn, yam, lima/butter beans, peas, legumes and lentils 
 
 Most fruits, non-starchy vegetables and carrots 
 
 Medium glycemic index foods include: 
 
 Whole wheat, rye and pita bread 
 
 Quick oats 
 
 Brown, wild or basmati rice, couscous 
 
 High glycemic index foods include: ||||| Abstract 
 
 Background: Postprandial glucose (PPG) and insulin responses play a role in carcinogenesis. We evaluated the association between dietary glycemic index (GI) and glycemic load (GL), markers of carbohydrate intake and PPG, and lung cancer risk in non-Hispanic whites. 
 
 Methods: GL and GI were assessed among 1,905 newly diagnosed lung cancer cases recruited from the University of Texas MD Anderson Cancer Center (Houston, TX) and 2,413 healthy controls recruited at Kelsey-Seybold Clinics (Houston, TX). We assessed associations between quintiles of GI/GL and lung cancer risk and effect modification by various risk factors. ORs and 95% confidence intervals (CI) were estimated using multivariable logistic regression. 
 
 Results: We observed a significant association between GI [5th vs. 1st quintile (Q) OR = 1.49; 95% CI, 1.21–1.83; P trend <0.001] and lung cancer risk and GI ac (5th vs. 1st Q OR = 1.48; 95% CI, 1.20–1.81; P trend = 0.001) and lung cancer risk. We observed a more pronounced association between GI and lung cancer risk among never smokers (5th vs. 1st Q OR = 2.25; 95% CI, 1.42–3.57), squamous cell carcinomas (SCC; 5th vs. 1st Q OR = 1.92; 95% CI, 1.30–2.83), and those with less than 12 years of education (5th vs. 1st Q OR = 1.75; 95% CI, 1.19–2.58, P interaction = 0.02). 
 
 Conclusion: This study suggests that dietary GI and other lung cancer risk factors may jointly and independently influence lung cancer etiology. 
 
 Impact: Understanding the role of GI in lung cancer could inform prevention strategies and elucidate biologic pathways related to lung cancer risk. Cancer Epidemiol Biomarkers Prev; 25(3); 532–9. ©2016 AACR.
– That morning bagel, bowl of corn flakes, or packet of instant oatmeal could be increasing your risk of lung cancer, according to a study published this month. NBC News reports researchers in Texas found a link between foods with a high glycemic index and lung cancer, which kills more Americans per year than any other cancer. After comparing the diets of more than 1,900 people with lung cancer and more than 2,400 without it, researchers found a 49% increase in lung cancer risk for those who ate the most high glycemic foods versus those who ate the least, according to the Telegraph. Forbes reports the glycemic index measures how quickly carbs raise blood sugar levels. Foods with a high glycemic index include white bread, many breakfast cereals, white rice, pineapple, melons, popcorn, and more. High glycemic foods have been linked to other cancers in the past, but doctors aren't sure why they would contribute to lung cancer. One possibility is that as foods with a high glycemic index increase insulin levels, they also increase insulin-like growth factors. Those IGFs could play a role in growing small tumors. Another interesting result from the study: nonsmokers who ate a lot of high glycemic foods were more than twice as likely to have lung cancer than nonsmokers who ate the least amount of those foods. While the study isn't conclusive, the doctor who led it says eating foods with a low glycemic index may lower the risk of lung cancer. Those foods include stone-ground whole wheat bread, rolled oatmeal, non-starchy vegetables, and most fruits. (These five states have the most cancer deaths.)