One of the most important effects of the reishi mushroom is to boost human immune systemTrusted Source.
While some details are still uncertain, test-tube studies have shown that reishi can affect the genes in white blood cells, which are critical parts of your immune system.
What’s more, these studies have found that some forms of reishi may alter inflammation pathways in white blood cells (5Trusted Source).
Research in cancer patients has shown that some of the molecules found in the mushroom can increase the activity of a type of white blood cell called natural killer cellsTrusted S
Natural killer cells fight infections and cancer in the body Trusted Sou
Another study found that reishi can increase the number of other white blood cells (lymphocytes) in those with colorectal cancer Trusted Sou
Although most immune system benefits of reishi mushroom have been seen in those who are ill, some evidence has shown that it can help healthy people, too.
However, other research in healthy adults showed no improvement in immune function or inflammation after 4 weeks of taking reishi extract Trusted Sourc
Overall, it is clear that reishi impacts white blood cells and immune function. More research is needed to determine the extent of the benefits in the healthy and ill.