Carbohydrates Possibly Linked to Breast Cancer

BALTIMORE -- Scientists have found that women in Mexico with high-carbohydrate diets were twice as likely to get breast cancer as those who ate less starch and sugar, reported the Baltimore Sun.

The study is one of the few to probe how the popular but controversial low-carb diet might affect the odds of getting cancer, rather than heart disease. The new findings also don't mean that it is safe or healthful to eat lots of meat, cheese or fats, as many people who go on low-carb diets do, experts say.

"There are many concerns with eating diets high in animal fat," said Dr. Walter Willett, chief of nutrition at the Harvard School of Public Health. "If people do want to cut back on carbohydrates, it's really important to do it in a way that emphasizes healthy fats, like salads with salad dressings."

Willett worked on the study with doctors at Instituto Nacional de Salud Publica in Cuernavaca, Mexico. It was funded by the U.S. Centers for Disease Control and Prevention, the Ministry of Health of Mexico and the American Institute for Cancer Research. Results were published Friday in the journal Cancer Epidemiology, Biomarkers & Prevention.

Being overweight is known to raise risk, but the new study took that into account and still found greater risk from high carbohydrate consumption. Scientists say carbs rapidly raise sugar in the blood, which prompts a surge of insulin. This causes cells to divide and leads to higher levels of estrogen in the blood, both of which can encourage cancer.

Little research has been done on carbs' effect on breast cancer, and results have been mixed. One study last year found greater risk among young women who ate a lot of sweets, especially sodas and desserts.

For this study, researchers enrolled 475 women newly diagnosed with breast cancer and a group of 1,391 healthy women in Mexico City who were matched for factors that affect the odds of getting the disease. Those who got 62 percent or more of their calories from carbs were 2.22 times more likely to have breast cancer than those in the lowest category, with a carb intake of 52 percent or less.