Anyway, reishi mushrooms have roots in Eastern Asia, where Chinese, Korean, and Japanese royalty, herbalists, and spiritual practitioners have used the antioxidant-rich fungi for more than 2,000 years to increase longevity, boost immune function, and treat illnesses.
Also known as lingzhi (Chinese for "spirit plant"), reishi are pretty rare in the wild, growing in humid conditions on plum, maple, chestnut, oak, and hemlock trees. Fortunately, humans have learned how to cultivate the "10,000-year mushroom," so you don't have to find a spiritual guru to get reishi -- you can just order it on Amazon.
About those benefits, though -- reishi may help prevent cancer
The sugar molecules in reishi mushrooms stimulate the immune system, giving a kick in the pants to immune cells like T-cells and macrophages, whose job it is to attack cancer and other foreign cells. This is a good preventative measure, but some cancer patients also use reishi to keep their cancer in remission.