A nine-year study into how our bodies process sugar has shed new light on cancer development, and how sugar-heavy diets may wind up increasing the risk of tumor growth.

By better understanding how cancer cells metabolize sugars we eat, scientists are a step closer to figuring out how those cells trigger the development of cancerous diseases. The research also helps scientists understand how cancer cells’ metabolism of sugar relates to the aggressiveness of cancerous tumors.

“Our research reveals how the hyperactive sugar consumption of cancerous cells leads to a vicious cycle of continued stimulation of cancer development and growth,” said Johan Thevelein, one of the researchers, in a statement.

The findings are the product of nine years of research by three Belgian scientists, published this week (Oct. 13) in the journal Nature Communications.

The sugars that people eat—be they from apples, bananas, breads, or soda—are crucial for life because the cells in our bodies use them to create energy. But cancer cells eat a lot more sugar than the healthy cells in our bodies, turning the glucose—a byproduct of the sugar we eat—into an excess of lactic acid, which has been found to help fuel tumor growth. For years, scientists have been working to better understand that process, which is known as the Warburg effect.

To conduct their work, the Belgian researchers observed how yeast eats and processes sugar to better understand how so-called Ras proteins—which are in all animals—are activated.For the last quarter century, scientists have learned that Ras proteins are key components of our bodies’ signaling networks, which control cell growth and differentiation. Sometimes those Ras cells are mutated; mutated Ras cells are often found in abundance in human tumors. Put in simple terms, the researchers found that excess sugar caused the yeast to produce overactive, fast-growing Ras proteins.

There’s still more work to be done to better understand how certain cells eat and process sugar, and the research doesn’t point to any guidance as to how people might alter their diets to decrease chances of cancer growth. Still, it suggests there may be yet another reason for people to move away from sugar-heavy diets, which have already wreaked havoc on populations, particularly in the US, where obesity, heart disease, and Type 2 diabetes—all connected to sugar—are rampant.