All forms of breast cancer are either estrogen-receptor positive or estrogen-receptor negative. The ER-negative forms tend to be more aggressive because they don’t respond well to hormone therapy, which is why women diagnosed with ER-negative breast cancer have very few options for recovery. In the trials with mice, the research team found that when mice ate a diet rich in broccoli sprouts and green tea, their tumors transformed from ER-negative to ER-positive and became easily treatable with the hormone drug tamoxifen, an estrogen receptor inhibitor.
“This is an important breakthrough that may give hope to those with estrogen receptor-negative breast cancer that is often fatal,” Tollefsbol said.
The link between a diet rich in cruciferous vegetables and preventing and treating certain types of cancer has been studied previously, but this is the first research to directly show that consuming these compounds can change this lethal variety of cancer into a treatable form.
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Tollefsbol has also researched the efficacy of an epigenetic diet in treating other forms of cancer as well.
“We have looked primarily at breast cancer but have also received good data for effects in colon cancer,” Tollefsbol said. “Other [studies] have shown that the compounds given individually, rather than in combination as we have introduced, can be quite effective for prostate cancer and many other cancers as well.”
Clinical trials on humans are next.
“We’re thinking about initially starting with giving [study participants] the whole foods, about two cups of broccoli sprouts a day and about two to three cups of green tea a day,” Tollefsbol said. “However, it is possible that we may move to a supplemental pill that combines these compounds if we find that there are any issues with patient compliance.”
The American Cancer Society estimates that about 252,710 new cases of breast cancer will be diagnosed in 2017 in the US and about 40,610 women will die from the disease. This plant-based diet approach could provide a more effective treatment for women suffering from ER-negative breast cancer in the US and around the world.
Tollefsbol noted that such a diet could be useful in preventing cancer as well as treating it.
“Our studies indicate that it can help to prevent the incidence of breast cancer in transgenic mice that are programmed to develop breast cancer,” he said. “We also recommend this diet for cancer prevention.”
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