A team headed by Prof. Dr. Jenny Chang-Claude, Deutsches Krebsforschungszentrum Heidelberg (DKFZ), The German Cancer Research Center, summarized the results of several studies in a meta-analysis and showed that a diet rich in phytoestrogens lowers the risk of developing breast cancer after menopause.
Importance of consuming lignans:
The most important type of phytoestrogens in Western diet are lignans, which are contained in seeds, particularly flaxseeds, as well as in wheat and vegetables. These substances are turned into enterolactone, which is absorbed by the mucous tissue and which was determined by the Heidelberg researchers as a biomarker in the patients’ blood.
What did the DKFZ study involve?
DKFZ researchers used the MARIE study to take blood samples of 1,140 women who had been diagnosed with postmenopausal breast cancer. A mean observation was made for six years and reseachers related enterolactone levels to clinical disease progression.
What were results of the study?
Compared to the study subjects with the lowest enterolactone levels, the women with the highest blood levels of this biomarker had an approximately 40 percent lower mortality risk. When the scientists additionally took account of the incidence of metastasis and secondary tumors, they obtained a similar result, women with the highest enterolactone levels also had a lower risk for such an unfavorable disease progression.
“We now have first clear evidence showing that lignans lower not only the risk of developing postmenopausal breast...
cancer, but also the mortality risk,” says Jenny Chang-Claude.
Enterolactone helps in arresting cancer growth:
Chang-Claude concluded that the result was significant only for the group of tumors that have no receptor for the estrogen hormone (ER-negative tumors). This gives reason to suspect that enterolactone protects from cancer not only by its hormone-like effect.” Indeed, studies of cells and animals had already provided evidence suggesting that the substance also has an influence on cancer growth irrespective of estrogen. Thus, it promotes cell death and inhibits sprouting of new blood vesse firmly emphasized: “By eating a diet that is rich in wholemeal products, seeds and vegetables, which is considered to be health-promoting anyway, everybody can take in enough lignans. At the present time, we can only discourage people from taking any food supplements.” says Jenny Chang-Claude. “Our studies will help achieve more clarity in this important question, which also concerns our daily diet.”