Plant Compound Reduces Breast Cancer Mortality

Phytoestrogens are plant compounds which, in the human body, can attach to the receptors for the female sexual hormone estrogen and which are taken in with our daily diet. A number of findings have attributed a cancer protective effect to these plant hormones. At the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ), a team headed by Prof. Dr. Jenny Chang-Claude summarized the results of several studies in a meta-analysis last year and showed that a diet rich in phytoestrogens lowers the risk of developing breast cancer after menopause. Now the Heidelberg researchers wanted to find out whether phytoestrogens also have an influence on the course of breast cancer. Prior investigations on this topic had provided contradictory results.

The most important type of phytoestrogens in our Western diet are lignans, which are contained in seeds, particularly flaxseeds, as well as in wheat and vegetables. In the bowel, 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.

From 2002 to 2005, the DKFZ researchers used the MARIE study to take blood samples of 1,140 women who had been diagnosed with postmenopausal breast cancer. After a mean observation time of six years, they related enterolactone levels to clinical disease progression.

The result: 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. There had been prior studies to determine the lignan intake by means of dietary surveys. But the results of such surveys are often unreliable and, in addition, there are big differences in the way individuals actually process the plant substances into effective metabolic products. Therefore, the Heidelberg team chose the more reliable measurement of biomarkers.

However, Chang-Claude narrowed down the result: “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 vessels.

“In order to find out whether enterolactone also inhibits the aggressiveness of estrogen receptors in estrogen-positive tumors, we would need to expand this study to include much larger groups of women,” said Jenny Chang-Claude. Moreover, the scientist 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.”

Phytoestrogens have been the subject of intense scientific debates in past years. On the one hand, the results of several studies of cells as well as epidemiological findings suggest that they have a cancer protective effect. Another observation that may be interpreted in this direction is that Asian women are less frequently affected by breast cancer. Their soy-rich diet contains large amounts of another type of phytoestrogens, isoflavones. On the other hand, scientists fear that isoflavones might imitate the growth-promoting properties of real hormones and, thus, accelerate hormone-dependent tumors such as breast cancer and prostate cancer. “It has not yet been finally determined whether lignans in the body imitate the hormone effect or, on the contrary, counteract it,” says Jenny Chang-Claude. “Our studies will help achieve more clarity in this important question, which also concerns our daily diet.”

 

Reference

Buck K, Vrieling A, Zaineddin AK, Becker S, Hüsing A, Kaaks R, et al. Serum Enterolactone and Prognosis of Postmenopausal Breast Cancer. J Clin Oncol. 2011 Sep 6. [Epub ahead of print].

 

Is Estrogen Going to Your Head?

Growing deposits of bone in the skull means your hormones are out of whack, warns researcher Prof. Israel Hershkovitz at Tel Aviv University 

Girls are growing up faster than ever — and not only when it comes to their taste in fashion and music. Their bodies are reaching puberty at an increasingly earlier age, and this trend to rapid maturity continues through women’s adult lives. That’s bad news, according to Tel Aviv University researchers. Women today are more likely to develop Hyperostosis Frontalis Interna (HFI), a hormonal condition once typically found in post-menopausal women, earlier and more frequently than the female population a century ago.

Women’s hormonal balances are changing and taking a physical toll, says  and his graduate student Hila May of TAU’s Sackler Faculty of Medicine, together with Dr. Natan Peled of Carmel Medical Center in Haifa. That balance is being affected by the hormones we now consume in our food and by our changing fertility patterns, such as having children later in life. Women today are 2.5 times more likely to develop HFI than they were 100 years ago, the study found.

Their research recently appeared in the American Journal of Human Biology 

Prof. Israel Hershkovitz

Sounding the alarm

HFI occurs when a hormonal imbalance leads to the growth of lesions, or bone masses, in the inner skull. This may lead to symptoms such as chronic headaches, weight gain, and thyroid irregularities, and is suspected to have multiple causes, including lifestyle, fertility habits, nutrition, and environment.

To track the growing prevalence of HFI, Prof. Hershkovitz and fellow researchers compared 992 historic female skulls from museum collections aged 20 to 90 years with CT scans of 568 living female participants ranging from 20 to 103 years old. Not only was prevalence of HFI found to be 2.5 times higher in the latter group, but the researchers also discovered that the average age of women who suffered from HFI had fallen drastically.

An age-dependent condition, HFI was once known to primarily strike post-menopausal women, who had then been exposed moderate levels of estrogen throughout their lives. Now it is appearing as well in pre-menopausal women, who have been exposed to higher levels of estrogen earlier in their lifetimes.

Their survey found that only 11 percent of 19-20th century women in the age range 30-39 had HFI. However, in the modern sample, 40 percent of women in that age group were found to be developing the condition. Any number of factors could be to blame, May says. Hormones added to food are one culprit, but not the only one. Women are now having fewer children and getting pregnant later in life. The period of time women breastfeed has also been shortened considerably, from three to four years a century ago to an average of less than six months today. Women are also consuming additional amounts of hormones through birth control medications. It’s now common for girls to be on “the pill” in their early teenage years.

There is currently no cure for HFI, but detection of the condition remains important, says Prof. Hershkovitz, who was among the first scientists to investigate the development of HFI in the human skull. “It’s an alarm within the human body, telling you that your body is out of balance and there is a pathological process going on,” he explains. It can also be a symptom of metabolic diseases.

Not just for women

Although most frequently found in the female population, HFI is not an exclusively female condition. Prof. Hershkovitz points to the case of Farinelli, a famous male opera singer in the 18th century, who suffered from HFI probably as a result of castration to preserve his falsetto voice.

Prof. Hershkovitz, Dr. Peled and May discovered a high prevalence of HFI in men who have been treated for prostate cancer. One of the treatments for prostate cancer, explains Prof. Hershkovitz, is chemical castration. Since the cancer itself feeds on testosterone, this treatment option literally starves the disease, but leads to higher levels of estrogen in the body.

Prof. Hershkovitz does not counsel against the prostate treatment, however — it is part of the physiological “cost-benefit” balance of the body. “If you treat one system in the body, another must pay,” he says. In this case, he says, it’s worth the price.

 

Reference

May H, Peled N, Dar G, Abbas J, Hershkovitz I. Hyperostosis frontalis interna: What does it tell us about our health? Am J Hum Biol 2011; 23 (3): 392-397.