The amounts of each one of these antioxidants present in mushrooms - ergothioneine and glutathione - vary largely by strain and type. There are many different species that exist which have these two antioxidants. The porcini species - a part of the wild variety - has the highest amount. Though the more common types had less of the antioxidants than the porcini, they still had way more than many other food items. White button mushrooms, for example, will still provide a great deal of these antioxidants to the body when readily consumed.