Reishi mushrooms are large, shiny-looking mushrooms native to Asia. They have a long history in traditional Eastern medicine, believed to promote long-term health and longevity.
Texts documenting ancient Chinese medicine praise reishi mushrooms for their ability to:
- Strengthen heart function
- Increase memory
- Detoxify the body
Over time, the mushrooms’ use extended to treat a variety of conditions, like asthma, dizziness, insomnia, and irregular heartbeat.
While not all of reishi mushrooms’ traditional uses are backed up by modern science, studies show that they have biological effects that can benefit your health. You can eat reishi mushrooms fresh, and they’re also sold as a nutritional powder, dietary supplement, and tea.
Reishi mushrooms have more than 400 different nutrients. This includes beta-glucans and triterpenoids, compounds that can lower blood sugar and blood pressure levels, reducing your diabetes and heart disease risk.
Studies show the mushrooms also have high antioxidant activity, which protects your body from cell damage that can increase your risk of many chronic diseases.
While research is ongoing, reishi mushrooms may also help:
Boost Your Immune System
Reishi mushroom’s claim to promote long-term health may be due to their effect on our white blood cells — the cells that flow through the bloodstream to fight viruses, bacteria, and other pathogens, protecting the body from illness. Studies show reishi mushrooms may increase the number of white blood cells in your body and improve their function.
Promote Anti-Cancer Effects
Reishi mushrooms contain beta-glucans, complex sugars that can slow or stop tumor growth. While more research is needed in humans, lab studies show that reishi mushrooms also stimulate a type of white blood cell called “natural killer cells” that target abnormal — including cancerous — cells.
Chronic fatigue is a condition where tiredness isn’t relieved by getting enough rest. The causes of ongoing fatigue aren’t well understood, but experts think it could be triggered by a combination of factors like infections, immune system problems, hormonal imbalances, and stress.
Studies show that reishi mushrooms may reduce the severity of chronic fatigue. This effect may be due to the mushrooms’ ability to boost the immune system and fight free radical damage. Reishi mushrooms can also help regulate the body’s testosterone levels, which promotes good energy levels.
Reishi mushrooms are considered safe for most people, and throughout their long medicinal history there’s no evidence of toxic effects. But because nutritional supplements are not well regulated, a product’s quality and consistency can vary by brand. Talk to your doctor before adding a new supplement to your diet to make sure you’re consuming a healthy product.
Reishi mushrooms may cause complications for some people. Consider the following before adding them to your diet:
May Increase Bleeding
Reishi mushrooms may increase the risk of bleeding in people taking blood thinners like warfarin. They may also increase bleeding during surgery, so doctors recommend discontinuing reishi mushrooms at least two weeks before a scheduled surgery.
Because reishi mushrooms can boost the immune system response, they may worsen symptoms in people taking immunosuppressant medications to treat conditions like rheumatoid arthritis, inflammatory bowel disease, or psoriasis.
Low Blood Sugar
Reishi mushrooms may decrease blood sugar, so taking them alongside blood sugar medication to treat diabetes may cause your blood sugar to go too low.
Low Blood Pressure
Studies show mixed results, but reishi mushrooms may lower blood pressure in some people. If you have low blood pressure, or use medication to lower your blood pressure, talk to your doctor before taking reishi mushrooms.
Amounts and Dosage
There is not adequate scientific research to determine a set recommended dose for reishi mushrooms. An effective amount may also depend on factors like age and underlying health conditions.
Studies base therapeutic doses on a range from 1.5 to 9 milligrams per day. Researchers report that nutritional products like powder, supplements, and teas don’t always list the ingredient content, however. According to their product reviews, most contain an average of about 100 milligrams of reishi mushrooms.