In ancient Egypt, mushrooms were a rare delicacy and were associated with immortality and were being consumed with meals as long as 4,500 years ago. Mushrooms are associated with longevity and strength, partly because some of the most popular mushrooms are known for stimulating the immune system. Shiitake and maitake mushrooms, in particular, have been used in herbal remedies for centuries. Mushrooms have been used by many cultures throughout time as part of ritual and religion. The toxin psilocybin is found in certain mushrooms, and the use of psychedelic fungi has been documented in rituals dating back thousands of years.