Sunday June 30, 2013 (foodconsumer.org) -- A study in Cancer Epidemiology, Biomarkers & Prevention suggests that women eating too much carbohydrates particularly sucrose (cane sugar) and fructose may increase their risk for developing breast cancer.

The study led by I. Romieu from Instituto Nacional de Salud Publica in Cuernavaca, Mexico and colleagues shows women in the highest quartile of total carbohydrate intake were 122 percent more likely to develop breast cancer risk, compared with those in the lowest quartile. 

The authors hypothesized that high intake of carbohydrates may be a risk factor for breast cancer because intake of carbohydrates is associated with elevated levels of free insulin, estrogens, and insulin-like growth factor-1, which promote the development of breast cancer.

The current study involved 475 women aged 20 to 75 years who were diagnosed with breast cancer and 1391 controls residing in Mexico City.

As a result, intake of  carbohydrates    was found positively correlated with breast cancer risk. Specifically, women in the highest quartile of intake were 2.22 times as likely as those in the lowest quartile of total carbohydrate intake to develop breast cancer.   Sucrose and fructose were associated with the risk of breast cancer more strongly than other types of carbohydrates (such as starches).   But total fat intake was not associated with breast cancer risk.

The researchers concluded "In this population, a high percentage of calories from carbohydrates, but not from fat, was associated with increased breast cancer risk."

They also said that "This relation deserves to be investigated further, particularly in populations highly susceptible to insulin resistance." (reporting by Jimmy Downs)