Study links high sugar intake to increased breast cancer risk

High amounts of dietary sugar increased the risk that mice would develop breast cancer, and that it would spread to their lungs, MD Anderson researchers found in a recent study published in the journal Cancer Research.

Peiying Yang, Ph.D., the study’s co-author, said previous studies identified a link between dietary sugar and breast cancer, possibly as a result of inflammation. However, the studies didn’t demonstrate the biological reasons behind the sugar-breast cancer connection, said Yang, assistant professor of Palliative, Rehabilitation and Integrative Medicine at MD Anderson.

With this in mind, Yang and his team set out to determine the mechanism by which sugar affects breast cancer development in mice. They fed mice bred to have a high breast cancer risk several different diets, including a sucrose-enriched diet, a fructose-enriched diet, and a starch-control diet.

“We found that just over half of the mice fed an amount of sugar comparable to that found in a typical western diet developed breast cancer, compared to less than a third of mice on a starch-control diet,” said study co-author Lorenzo Cohen, Ph.D., professor of Palliative, Rehabilitation and Integrative Medicine. “Furthermore, mice that were fed a diet high in two forms of sugar, sucrose or fructose, had a higher likelihood that their breast cancer would spread to their lungs.”

The researchers found that sugar intake affected an enzyme-signaling pathway, which in turn boosted levels of a type of fatty acid. They believe these processes could promote breast cancer tumor growth, but further research will be needed to see if what occurred in mice will transfer to people.

This study is particularly important, the researchers note, given that more than 100 pounds of sugar are consumed annually in the U.S. That translates to 30 teaspoons of sugar a day per person.

Learn more about sugar’s effect on breast cancer risk on MD Anderson’s website.