As estrogen is a known risk factor for some forms of breast cancer, there has been some concern that plant-based compounds with weak estrogen-like effects called phytoestrogens may increase the risk of breast cancer in women.

Studies investigating a possible association between phytoestrogens and breast cancer risk have yielded mixed results. Interestingly, some of the best data seems to suggest that some phytoestrogens may actually reduce the risk of breast cancer.

For example, a new German study found that regular consumption of three particular phytoestrogens was associated with a reduced risk of breast cancer in post menopausal women: soy foods (17% reduction) sunflower and pumpkin seeds (34% reduction).

The study consisted of 2,884 postmenopausal women diagnosed with breast cancer and 5,509 age-matched “controls” without breast cancer. Each filled out detailed food-frequency questionnaires and answered additional questions regarding consumption of specific phytoestrogen-rich foods. Each woman’s individual risk factors for breast cancer were also assessed and considered when analyzing the data.

Unanswered Questions

From this study it appears that at least some forms of phytoestrogens may be beneficial, even though they act on some of the same hormone receptors that estrogen normally stimulates. While this may seem counterintuitive, it supports other research that suggests that phytoestrogens are more complex than once thought.

In fact, some believe that phytoestrogens may actually block the effects of estrogen on estrogen receptors within breast cells. We’ll need more research to understand the exact cause and effect of phytoestrogens on breast cancer.

Sources:

PubMed

Dr. Robert Wascher

Researchers investigating the association between soy food intake and breast cancer outcomes among survivors found that soy food consumption did not increase the risk of cancer recurrence or death among survivors of breast cancer.

The research was part of a multi-national collaborative study, the After Breast Cancer Pooling Project, which involved over 16,000 women between the ages of 20 and 83 years who had invasive primary breast cancer.

The researchers assessed the intake of soy isoflavones among the women after breast cancer diagnosis using food frequency questionnaires. Breast cancer outcomes were assessed, on average, nine years after cancer diagnosis.

Women in the highest intake category of more than 23 mg of isoflavones per day had a 9 percent reduced risk of mortality and a 15 percent reduced risk for recurrence, compared to those who had the lowest intake level. The average daily soy isoflavone intake among U.S. women was 3.2 mg; however, in a group of women in China, the amount was significantly higher at 45.9 mg.

The study appears to ease concerns about the safety of soy food for women with breast cancer because soy foods contain large amounts of isoflavones that are known to bind to estrogen receptors and have both estrogen-like and anti-estrogenic effects. One concern was that isoflavones might increase the risk of cancer recurrence among breast cancer patients because they have low estrogen levels due to cancer treatment. Another issue in question was whether isoflavones interfere with tamoxifen treatment as they both bind to estrogen receptors.

So, for now it appears women with a history of breast cancer can enjoy soy.

Sources:

American Association for Cancer Research

According to a recent report in Herbalgram (published by the American Botanical Council), domestic sales of herbal and botanical dietary supplements rose by a very healthy 4.8 percent in 2009, exceeding an estimated $5 billion for the very first time, dispelling concerns about any linkage between the "imaginary value" of supplements and the Tooth Fairy described in a recent Reader's Digest article.

The biggest increase in herbal supplement sales was seen in the mass market sector (grocery stores, drug stores, warehouse clubs and c-stores) with a jump of nearly 15 percent, nearly tripling that of natural and health food chains like Whole Foods and specialty retail outlets like GNC.

What follows are the top 10 selling herbal dietary supplements among U.S. food, drug and mass market outlets. (For expanded, more complete lists, hit the free report link below.)

1. Cranberry

2. Soy

3. Saw palmetto

4. Garlic

5. Echinacea

6. Gingko

7. Milk thistle

8. St. John's wort

9. Ginseng

10. Black cohosh

No doubt, you have many options about where to buy a healthy, good-for-you supplement. But, do you really know what you're getting -- namely quality and safety -- for the amount you're spending each month? Review CNCA’s Nutritional Supplement Quality -- The Facts, just to be sure.

HerbalGram, No. 86, pp. 62-65, Summer 2010 Free Full Text Report

Nutraceuticals World May 7, 2010