Reishi extract has been used in Traditional Chinese Medicine to treat arthritis and other forms of inflammation for over 2,000 years. Also commonly known by its Latin name as "Ganoderma," or Chinese "Ling Zhi," Reishi is by far the most searched medicinal mushroom on the Internet with over 200,000 searches per month. And although it may not be the panacea ("cure-all") that some hold it to be, the fact that modern research confirms it as an inflammation modulator may help explain why it has long been heralded as such in the Orient.
Reishi frequently gets prescribed in Traditional Chinese Medicine for its analgesic, anti-inflammatory and anti-arthritic effects. Much recent research appears to validate this traditional use, as the majority of studies have yielded positive results. While looking through published articles on Reishi and arthritis, I found only two studies that showed inconclusive results, both of which were conducted by the same team of researchers. (1,2)
An American study conducted in 1993 by Lin et al. concluded that a water extract of Ganoderma lucidum (Reishi) demonstrated "significant anti-inflammatory activity." (4) A study out of India ten years later found that an extract of Reishi decreased inflammation in conditions of acute edema and chronic edema by 56% and 60%. (3) Seven additional research papers were found during the writing of this article that all concluded that Reishi is a potent anti-inflammatory medicinal mushroom. (5,6,7,8,9,10,11)
Other research has been conducted on Reishi extract that relate specifically to arthritis. In 2006, Kenneth Blum et al. published findings in support of both the effectiveness and safety of using Reishi extract for "joint health," providing "clinical evidence" to back up their claim. (12)
Also that same year, a Chinese study by Xi Bao et al. came to the conclusion that Reishi plus another medicinal herbal remedy commonly used in China seemed to have a "beneficial immunomodulatory effect" on arthritis. (13)
The answer as to how, precisely, Reishi extract accomplishes this "immunomodulatory effect" may have been given by another Chinese study the following year, which states that an isolated Reishi polysaccharide peptide "significantly inhibited" RASF, which is an indicator of rheumatoid arthritis. (RASF stands for "Rheumatoid Arthritis Synovial Fibroblasts.") (14)
Five additional studies are included in the references that report positive findings between Reishi and arthritis. (15,16,17) One goes so far as to state that Reishi shows favorable results when compared to prednisone, and is free from the side effects. (18) In extension of this, a separate study also found that not only was Reishi extract free of the side effects of prednisone, it could also help balance the existing side effects of prednisolone* such as cell toxicity and proteinuria. (*Prednisolone is the active compound of prednisone. The liver breaks down prednisone and converts it to prednisolone.) (19)
In conclusion, the findings of 17 out of the 19 scientific papers referenced for this article agree that Reishi can help support joint health in cases of arthritis. However, it is important to always consult a licensed medical practitioner before using any herb for medicinal purposes, and to never change the use of existing prescription drugs without talking to your doctor about it first.
Name clarification: The Japanese name Reishi includes many closely related species. By far the most prevalent is Ganoderma lucidum (Common Reishi or Red Reishi), a species rare in the U.S. but common in South East Asia. The English common name for Ganoderma lucidum is Varnished Conk. In China, its known as Ling Zhi.
Several closely related species of Ganoderma also go by the name of "Reishi". Most common of these are the Hemlock Reishi (Ganoderma tsugae) found on Hemlocks in the Appalachian Mountains, and the Chinese species "Black Reishi" (Ganoderma sinense). Less common are Ganoderma resinaceum (sometimes called "Red Reishi," although that name is more often used for G. lucidum), Ganoderma neo-japonicum (no common name other than "Reishi"), and Ganoderma japonicum (Purple Reishi).