Mushrooms Inhibit Aromatase. That's Good.

Because aromatase makes female hormones - estrogens. And too much estrogen - whether from what we make in our bodies (men make estrogens too) or what we absorb from our environment, and truth be told we're eating, drinking, and breathing more estrogenic compounds now than at any other time in human history (sunscreens, moisturizers, pesticides, herbicides, commercially raised beef/chicken/pork, plastics) - "have been implicated in a variety of medical problems."

(See this post for background on aromatase and how bodybuilders, women at risk for breast cancer, and men as they enter middle age benefit from its inhibition. With the surge in environmental endocrine disruptors (e.g. BPA), aromatase inhibitors are becoming more important for everyone.)

Another food that can inhibit aromatase is the mushroom. Although grapes, grape seeds, and red wine also inhibit aromatase, their consumption has a downside: the alcohol in wine is implicated in breast cancer and drinking grape juice means intaking lots of sugar and associated calories.

Dr. Shiuan Chen¹ has devoted his career to aromatase, and to investigating foods that inhibit it. A few of his studies:

From early 1998:

"The phytoestrogen studies will help to determine which fruits and vegetables (those containing the appropriate phytoestrogens) should be included in the diet of postmenopausal women in order to reduce the incidence for breast cancer by inhibiting estrogen biosynthesis in breast tissue."
- Aromatase And Breast Cancer, Frontiers in Bioscience, 1998

2001:

"The present study was undertaken to screen and evaluate a number of vegetables as potential natural sources of aromatase inhibitors.
...
Using an in vitro human placental microsome aromatase assay, the white button mushroom was found to be a potent inhibitor of aromatase.
...
Of the other extracts evaluated, celery had a modest inhibitory effect. Extracts prepared from green onion, carrot, bell pepper, broccoli and spinach did not inhibit aromatase under these experimental conditions.
...
The white button, shiitake, portabello, crimini and baby button mushroom varieties demonstrated the ability to inhibit aromatase activity in an in vitro assay. The work presented here focused on the white button mushroom because it demonstrated potent inhibition and is easily available during all seasons. Furthermore, the white button mushroom is less costly than other varieties of mushrooms, making it more readily purchased by the average consumer.
...
These results suggest that diets high in mushrooms may modulate the aromatase activity and function in chemoprevention in postmenopausal women by reducing the in situ production of estrogen."
- White Button Mushroom Phytochemicals Inhibit Aromatase Activity and Breast Cancer Cell Proliferation, The Journal of Nutrition, 2001

2006:

"White button mushrooms are a potential breast cancer chemopreventive agent, as they suppress aromatase activity and estrogen biosynthesis.
...
Consumption of 100 g* of mushrooms per day would be sufficient to suppress breast tumor growth in women."
- Anti-Aromatase Activity Of Phytochemicals In White Button Mushrooms (Agaricus Bisporus), Cancer Research, 2006

* 100 g is a little over 1 cup of raw, whole, white mushrooms. One portabella cap is about 50 g. Chen also said, "the anti-aromatase effect of mushrooms remains even after they are cooked."
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Translating science into reality, here's Mark Bittman preparing bok choi with shiitake mushrooms:


His accompanying article in the New York Times' Dining Section:
Vegetables Dressed in Chinese Robes

Don't miss 3:59 minutes: "That's a big shiitake."
________¹ Shiuan Chen PhD is Director and Professor, Division of Tumor Cell Biology, Beckman Research Institute, City of Hope, Duarte, CA
A few more of Dr. Chen's studies.
Dr. Chen answers some layman's questions.
Photo: Bix