Most of the discussion about carbohydrates circles around weight control, especially whether they or fats represent the most dieting dangers. But a study out of New York University adds a different dimension to the dialogue: the energy-dense carbs found in foods such as sugary beverages were associated with a 3 times greater risk of prostate cancer.
The good news coming out of the study was that carbo-rich foods like legumes, non-starchy vegetables, fruits and whole grains were collectively associated with a 67 percent lower risk for breast cancer.
“One of the most important findings here is that the type of carbohydrate-containing foods you consume can impact your cancer risk,” said Nour Makarem, the study’s lead author. “It appears that healthy carbohydrate sources, such as legumes, tend to protect us from cancer, but non-healthy ones, such as fast foods and sugary beverages, seem to increase the risk of these cancers.”
The study examined the health records of 3,100 subjects, tracked since the early 1970s. The researchers sorted all the study participants' foods sources by glycemic index, which is the metric used to gauge dietary carbohydrate quality based on a food’s relative impact on blood sugar levels as compared to a reference food. The also tracked the foodstuffs' glycemic load, which is a measure of both the quantity and quality of carbohydrates in a given food item. These carb data were then cross-referenced versus the individual volunteers' rates of cancer.
“Our study showed very strong associations between certain foods and cancer, in particular with prostate cancer,” said Makarem. “There had not been very many studies on food sources and prostate cancer previously.”
Processed lunch foods and especially sugary beverages (this includes the so-called “fruit juices” as well as soda) were the big cancer-causing culprits.
“Americans consume almost half of their added sugars in beverages,” said Makarem. “Sugar-sweetened beverages have been shown to increase the risk of obesity and diabetes, and our study documents that they may also have a detrimental impact on cancer risk.”
But foods with a low glycemic index, such as whole grains, legumes, most fruits an starchy vegetables had the opposite effect on breast cancer, lowering the risk by 67 percent.
What's the science? Previous studies have indicated that malignant cancer cells thrive on sugar.
“Current cancer prevention guidelines recommend avoiding sugary drinks and limiting the consumption of energy-dense foods, which tend to be high in refined carbohydrates,” said Makarem. “I think our findings add to the body of evidence behind this recommendation and strengthen the associations between these types of food and cancer.”
The research was presented at the American Society for Nutrition Scientific Sessions and Annual Meeting during Experimental Biology 2016.