Cancer researchers in Texas have a word of advice for women at risk of breast cancer – go easy on the sugar.
In a report, the University of Texas MD Anderson Cancer Center said high amounts of sugar, prevalent in the typical Western diet, may increase the risk of breast cancer and metastasis to the lungs.
The findings zeroed in on dietary sugar's effect on an enzymatic signaling pathway known as 12-LOX.
"We found that sucrose intake in mice comparable to levels of Western diets led to increased tumor growth and metastasis, when compared to a non-sugar starch diet," said Peiying Yang, assistant professor of Palliative, Rehabilitation, and Integrative Medicine. "This was due, in part, to increased expression of 12-LOX and a related fatty acid called 12-HETE."
There have been a few previous studies that looked for links between sugar and breast cancer. Some of these studies have suggested high levels of sugar can affect inflammation, which can be associated with cancer development.
"The current study investigated the impact of dietary sugar on mammary gland tumor development in multiple mouse models, along with mechanisms that may be involved," said co-author Lorenzo Cohen, professor of Palliative, Rehabilitation, and Integrative Medicine. "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 sugar industry was quick to respond to the study. The Sugar Association, a trade group, points out the results were based only on animal studies and charged the results are being sensationalized.
“As with other studies on this subject, this study has serious limitations that should be disclosed, particularly when the headlines are as serious as these have been,” the group said in a statement. “Not only do the authors misstate and exaggerate current U.S. sugar consumption and trends in consumption, they also claim the mice in the study were fed sugar levels comparable to levels in a Western diet. Yet, the data provided shows the mice were fed massive amounts of fructose (as part of sucrose) with the lowest level of fructose fed more than double U.S. consumption.”
But the authors say identifying risk factors for breast cancer is a public health priority. They say moderate sugar consumption is critical, and disagree with the Sugar Association about the current level of per capita consumption, claiming it is over 100 pounds per year.
The industry, however, may be correct in its contention that it is an over-estimate. As the New York Times reported in 2012, the Department of Agriculture lowered its estimate of per capita sugar consumption to 76.7 pounds annually.