Fructose consumption has increased considerably over the past five decades, largely due to the widespread use of high-fructose corn syrup as a sweetener in beverages and ultra-processed foods. New research from Washington University in St. Louis shows that dietary fructose promotes tumor growth in animal models of melanoma, breast cancer and cervical cancer. However, fructose does not directly fuel tumors, according to the study published Dec. 4 in the journal Nature.
Instead, WashU scientists discovered that the liver converts fructose into usable nutrients for cancer cells, a compelling finding that could open up new avenues for care and treatment of many different types of cancer.
“The idea that you can tackle cancer with diet is intriguing,” said Gary Patti, PhD, the Michael and Tana Powell Professor of Chemistry in Arts & Sciences and a professor of genetics and of medicine at the School of Medicine, all at WashU.
“When we think about tumors, we tend to focus on what dietary components they consume directly. You put something in your body, and then you imagine that the tumor takes it up,” Patti said. “But humans are complex. What you put in your body can be consumed by healthy tissue and then converted into something else that tumors use.”
“Our initial expectation was that tumor cells metabolize fructose just like glucose, directly utilizing its atoms to build new cellular components such as DNA. We were surprised that fructose was barely metabolized in the tumor types we tested,” said the study’s first author, Ronald Fowle-Grider, a postdoctoral fellow in Patti’s lab. “We quickly learned that the tumor cells alone don’t tell the whole story. Equally important is the liver, which transforms fructose into nutrients that the tumors can use.”
Using metabolomics — a method of profiling small molecules as they move through cells and across different tissues in the body — the researchers concluded that one way in which high levels of fructose consumption promote tumor growth is by increasing the availability of circulating lipids in the blood. These lipids are building blocks for the cell membrane, and cancer cells need them to grow.
“We looked at numerous different cancers in various tissues throughout the body, and they all followed the same mechanism,” Patti said.