We’ve reported on a new study that indicates sugar may lead to breast cancer, but there’s an even more alarming finding: once you have the cancer, you can actually make it worse by continuing to eat sugar.

The study in question found that high levels of fructose was tied to an increased risk of breast cancer tumors, a major problem since Western diets are so heavy in sugar and above health guidelines. In the study, about 50 to 58 percent of mice with a diet heavy in sucrose got mammary tumors by six months of age, compared to just 30 percent in mice that were not on a heavy sugar diet. But that may not be the most scary aspect about the study.

Most people think that once you have cancer, your diet isn’t going to change much about your status. But this study found that’s not the case: in fact, continuing to eat sugar after you get cancer may actually cause it to spread to other areas of the body.

That’s because fructose affects a metabolic process called 12-LOX, will helps a cancer metastasize, a medical term for spreading. As it turns out, most cancer patients die of a metastatic disease, not the original tumor, according to a Today report.

The scientists found in the study that the more sugar they fed the mice, the larger their tumors grew. Fructose in particular helped drive the inflammatory process, even more than glucose.

“Prior research has examined the role of sugar, especially glucose, and energy-based metabolic pathways in cancer development,” said Peiying Yang, Ph.D., assistant professor of Palliative, Rehabilitation, and Integrative Medicine, in a statement. “However, the inflammatory cascade may be an alternative route of studying sugar-driven carcinogenesis that warrants further study.”