A recent study done by researchers at The University of Texas MD Anderson Cancer Center reveals that the high amounts of sugar in the typical Western diet could not only increases the risk of breast cancer but also increases the chances of the tumor spreading to the lungs.
The full details of the study are published online in the Jan. 1, 2016 issue of Cancer Research.
In earlier studies which showed that sugar intake has an impact on breast cancer, the researchers concluded that the cause could have been because sugar helps increase inflammation. While that is not being disputed, the scientists feel that the inflammatory cascade may be an alternative route of cancer caused by sugar intake.
During the current study the researchers were able to demonstrate the effect of dietary sugar on an enzymatic signaling pathway known as 12-LOX (12-lipoxygenase).
As is the case in most such studies the scientists used lab mice to determine the effect of sugar on the risk of cancers.
They investigated the impact of dietary sugar on the development of mammary gland tumor in multiple mice. They also analyzed the mechanisms that may be involved in the tumor formation and spread. According to co-author Lorenzo Cohen, Ph.D., professor of Palliative, Rehabilitation, and Integrative Medicine, the team determined that it was fructose, in table sugar and high-fructose corn syrup, which was primarily responsible for facilitating 12-HETE production in breast tumors and their spread to the lungs.
They found that mice given sugar in levels comparable to human consumption in Western diets showed higher risk of increased tumor growth and metastasis, when compared to mice on a non-sugar starch diet. Only 30 percent of mice on a starch-control diet had measurable tumors, whereas a whopping 50 to 58 percent of the mice on sugar-enriched diets developed mammary tumors. The study also revealed that the number of lung metastases were significantly higher in mice on the sugar-enriched diet.
According to Peiying Yang, Ph.D., assistant professor of Palliative, Rehabilitation, and Integrative Medicine, this was because of increased expression of 12-LOX and a related fatty acid called 12-HETE.”
Given that the consumption of sugar in the U.S. has grown to over 100 lbs. per year per person and given the fact that an increase in consumption of sugar has been linked to the obesity epidemic, and also heart disease, identifying sugar intake a risk factor for breast cancer comes as no surprise. And it must now be seen as is a public health priority.
No previous studies have investigated the direct effect of sugar consumption on the development of breast cancer using breast cancer animal models or examined specific mechanisms, she added.
Based on the results of the study, the team believes that further investigation must be done to determine the mechanism by which dietary sucrose or fructose affects growth of breast tumors and their spread to the lungs.