Updated on 7/29/2005
You're no doubt referring to Agaricus blazei, a medicinal mushroom known in Japan as Himmematsutake and in this country as the Almond Portobello or Royal Sun Agaricus. This delicious, edible mushroom has a pronounced almond extract flavor and meaty texture; it also appears to enhance immune system activity.
Agaricus blazei was discovered in Florida but is best known from Brazil, where Japanese growers are producing it commercially. Japanese researchers have done the most studies on its medicinal effects. The mushroom contains beta glucans, a group of polysaccharides (complex sugars) believed to be the compounds responsible for its immune-boosting effects. In addition, research has shown that Agaricus blazei has anti-tumor and anti-viral activity, as well as moderating effects on blood sugar and cholesterol.
Oncologists in both Japan and Brazil use this mushroom in treatment protocols. I hope mushroom growers here will begin producing it as a gourmet species, because it is just delicious. In the meantime you can find it here in dried form as well as in extracts. One very good source for these is Fungi Perfecti in Olympia, Wash. (www.fungi.com).
I also recommend two other mushroom species, maitake and reishi, to cancer patients for their immune-enhancing and anti-cancer effects. Maitake (Grifola frondosa) is an edible mushroom known here as "hen of the woods" because in appearance it resembles the fluffed tail feathers of a nesting hen. In addition to its anti-cancer, anti-viral and immune-enhancing properties, maitake may also reduce blood pressure and blood sugar. Reishi mushrooms (Ganoderma lucidum) are too bitter to eat as food but are widely available in tea bags, capsules and liquid extracts. Animal studies have shown that reishi improves immune function and inhibits the growth of some malignant tumors; it is also a natural anti-inflammatory agent.
Andrew Weil, M.D.