Q. Are mushrooms friend or foe? As a fungus, does that exclude them from a vegetarian diet?
Mushrooms are not a fruit or a vegetable but they are classified as a fungus. Almost all edible mushrooms have agents in them that block the synthesis of estrogen. Because breast cancer is sensitive to estrogen this can help prevent breast cancer growth. Via a different mechanism other foods also help prevent breast cancer by blocking estrogen. Soy beans have genestein which is a weak phytoestrogen and binds the estrogen receptor sites in breast and other hormone sensitive tissue. This prevents the binding of the more powerful natural estrogens in the body. Because of our high fat, and animal protein diet. Americans generally overproduce estrogens.
One thing to be careful of in mushrooms are a fungus some people who are allergic to fungi in general should be aware of a possible allergic reaction to mushrooms.
I think it would be best if one does eat mushrooms to be sure to eat fresh and not canned as the processing may alter some of the good properties in the mushroom. Anything in a can is not as healthy as something fresh.