Sorry for the late post. I am not sure of the medicinal aspects of Maitake but the Matsutake is the rarest mushroom and the highest on the chart in terms of antioxidants, etc. I do know the Japanese 5 mushroom soup tastes great. Maitakes are grown in the wild in PA, too.
I am of the belief that even though certain foods are better for us than others, compacting them as an extract and taking capsules full of them may not necessarily be better. The body is designed to ingest food and extract the nutrients.
The Japanese believe one of the secrets of long life is to eat long root type vegetables. There are documented cases of certain people living off of gobo root (burdock,radishes as long as 40 feet, the sweet potatoe (yam) diet, etc. I tend to think the taste part is what makes it great and wonder if the people living longer just aren't exposed to as much in the cities, given they are typically on an island or in the mountains.
Just my two cents worth. Pass the mushrooms please.
Ed