HOUSTON, Jan. 1 (UPI) -- High levels of sugar typical of Western diets increase the risk for breast cancer tumors and metastasis to the lungs, according to a new study in mice.
Researchers at the University of Texas MD Anderson Cancer Center found fructose -- in table sugar and high-fructose corn syrup, and used in a high percentage of food items -- encouraged breast tumor growth, and helped it spread.
Previous research has linked dietary sugar to several types of cancer, according to the Dana-Farber Cancer Center, and other studies have shown a connection between sugar and inflammation that can lead to cancer development.
"The current study investigated the impact of dietary sugar on mammary gland tumor development in multiple mouse models, along with mechanisms that may be involved," Dr. Lorenzo Cohen, a professor of palliative, rehabilitation, and integrative medicine at MD Anderson, said in a press release. "We determined that it was specifically fructose, in table sugar and high-fructose corn syrup, ubiquitous within our food system, which was responsible for facilitating lung metastasis and 12-HETE production in breast tumors."
Researchers in the study, published in the journal Cancer Research, conducted four separate studies randomizing mice to diet groups fed one of four diets with differing levels of sucrose and fructose.
Between 50 and 58 percent of mice on a sucrose-enriched diet developed mammary tumors by the time they were six months old, but just 30 percent of mice on a starch-control diet had measurable tumors at the same age. There were also more lung metastases among mice fed diets higher in fructose or sucrose than in those given a starch-control diet, the researchers reported.
Cohen said data from the study suggests either form of sugar induced 12-LOX and 12-HETE production in breast tumor cells, causing tumors to grow. He said, however, further research is needed to find whether sugar has a direct or indirect effect on tumor growth.
"Prior research has examined the role of sugar, especially glucose, and energy-based metabolic pathways in cancer development," said Dr. Peiying Yang, an assistant professor of palliative, rehabilitation, and integrative medicine at MD Anderson. "However, the inflammatory cascade may be an alternative route of studying sugar-driven carcinogenesis that warrants further study."