High amounts of dietary sugar, a common component in the typical Western diet, may increase the risk of breast cancer and metastasis to the lungs, according to a study at The University of Texas MD Anderson Cancer Center, published in the online issue of Cancer Research.1
The researchers found that dietary sugar has an effect on the 12-lipoxygenase (12-LOX) enzymatic signaling pathway. A link between dietary sugar intake and breast cancer development, with a supposed role played by inflammation, has been proven in previous epidemiological studies.
In this study, the researchers investigated the direct effect of sugar consumption on the development of breast cancer, and the data suggest dietary sugar induces production of 12-LOX and 12-HETE, a related fatty acid.
To determine the impact of dietary sugar intake on cancer development and metastasis, the researchers conducted 4 different studies in which mice were randomized different groups in which they were fed according to 1 of 4 diets. Measurable tumors were found in 30% of mice fed a starch-control diet at age 6 months, whereas 50% to 58% of mice fed sucrose-enriched diet had developed mammary tumors.
In addition, the numbers of lung metastases were significantly higher in mice fed a sucrose- or a fructose-enriched diet, compared with mice fed a starch-control diet.
These findings indicate a signaling pathway responsible for sugar-promoted tumor growth in mice. However, the researchers report that further investigation into how sucrose or fructose affects breast tumor growth and metastasis is warranted, as how sugar intake induces 12-HETE and whether its effect is direct or indirect is not known.
1. University of Texas M.D. Anderson Cancer Center. Sugar in western diets increases risk for breast cancer tumor and metastasis [press release]. EurekAlert! web site. http://www.eurekalert.org/pub_releases/2016-01/uotm-siw123115.php. Posted January 1, 2016. Accessed January 4, 2016.