Aromatase converts androgen to estrogen. Because estrogen promotes the development of breast cancer, especially in postmenopausal women, compunds that inhibit aromatase are currently being used in the treatment of estrogen dependend cancers.

Aromatase activity is increased by factors including age, obesity, insulin, gonadotropins, and alcohol.

Along with certain medications, aromatase inhibitors--compounds which halt the conversion of androgen to estrogen-- occur naturally in some plant foods, including mushrooms.

References

ANTI-CANCER ACTIVITIES OF WHITE BUTTON MUSHROOMS. Shiuan Chen, Ph.D., Department of Surgical Research, Beckman Research Institute of the City of Hope, 1450 East Duarte Rd., Duarte, CA 91010