According to a new study in mice, elevated sugar levels typical of Western diets raise the risk for breast cancer tumors and metastasis to the lungs. University of Texas MD Anderson Cancer Center researchers have discovered that fructose boosts the growth of breast tumor, and helps it spread.
Fructose is present in table sugar and high-fructose corn syrup, and is used in high percentage in lot of food items.
As per the Dana-Farber Cancer Center, earlier research has linked dietary sugar to many kinds of cancer, and other studies have displayed an association between sugar and inflammation that can result into cancer development.
In a press release, Dr. Lorenzo Cohen, a professor of palliative, rehabilitation, and integrative medicine at MD Anderson, said that the present study has investigated the effect of dietary sugar on mammary gland tumor development in a number of mouse models, along with mechanisms that could have involvement in it.
Dr. Cohen added, “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”.
The study was published in the journal Cancer Research. During the study, researchers carried out 4 separate studies randomizing mice to diet groups given one of 4 diets with differing sucrose and fructose levels.
Cohen said the study data has suggested that either form of sugar induced 12-LOX and 12-HETE production in breast tumor cells, resulting into tumors growth. But, he has mentioned that further research is required to determine whether sugar has a direct or indirect effect on the growth of tumor.
A UPI report informed, "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. 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."
Research has also pointed to refined sugar as one of the culprits. But this factor is harder to pin down, since "sugar" is a very broadly used term, some sugars are vital nutrients and the body uses a form of sugar called glucose to generate energy.
Cohen's team used mice for their study but say they took many steps to make sure the process was as close as possible to what happens in people. They fed the mice sugar in doses very similar to what Americans eat every day and they used mice that are genetically predisposed to breast cancer in much the same way that many people are.
"It seems that fructose is driving this inflammatory process more than glucose," Cohen said. "It seems from these series of experiments that it really fructose that within the sucrose that is the driver of the tumorigenic process."
Any sugar helped make the tumors grow faster, but fructose did it significantly more.
It's still not quite clear just how this happens and it's not clear how the LOX-12 pathway affects cancer, Cohen and colleague Peiying Yang said. But it appears fructose makes LOX-12 more active.
There are other reasons to minimize sugar. Other studies show sugar-heavy diets can fuel heart disease, diabetes and Alzheimer's disease. But cutting sugar can lower blood pressure and blood sugar levels after only a few days, according to a report published in Today magazine.