Benign Prostatic HyperplasiaA double-blind trial found that an extract of Ganoderma lucidum mushroom was significantly more effective than a placebo in improving urinary symptoms in men with BPH.In a double-blind trial, an extract of Reishi mushroom (Ganoderma lucidum; 6 mg per day for 8 weeks) was significantly more effective than a placebo in improving urinary symptoms in men with BPH. Reishi extract appears to work by inhibiting 5-alpha-reductase, the enzyme that converts testosterone to its more active form, dihydrotestosterone (DHT).6
Type 2 DiabetesReishi may have some beneficial action in people with diabetes.Multiple studies using experimental and animal models of type 2 diabetes have reported anti-diabetes effects of reishi mushroom (Ganoderma lucidum) and its constituents.7,8,9,10 However, in a placebo-controlled trial with 84 participants, 3 grams per day of reishi mushroom for 16 weeks had no effect on glycemic control or any metabolic markers in people with type 2 diabetes.11
Type 1 DiabetesReishi may improve immune function and has demonstrated benefits in diabetic animals.Animal studies suggest reishi extract may improve immune function and wound healing in the context of type 1 diabetes.12,13 Furthermore, reishi has demonstrated anti-diabetic actions, such as lowering high glucose levels and increasing insulin levels, in animal studies.14 Clinical trials are needed to confirm these effects in humans.
HypertensionOne trial reported that reishi mushrooms significantly lowered blood pressure.
A double-blind trial reported that reishi mushrooms significantly lowered blood pressure in humans.15 The trial used a concentrated extract of reishi (25:1) in the amount of 55 mg three times per day for four weeks. It is unclear from the clinical report how long it takes for the blood pressure-lowering effects of reishi to be measured.
Hawthorn leaf and flower extracts have been reported to have a mild blood pressure–lowering effect in people with early stage congestive heart failure.16 In a double-blind study, supplementation with a hawthorn extract significantly decreased diastolic blood pressure in people with type 2 diabetes. The amount used was 1,200 mg per day of an extract standardized to 2.2% flavonoids corresponding to 6 per day of dried flowering tops.17
InfectionReishi supports the immune system in the fight against microbes.
HIV and AIDS SupportReishi is medicinal mushroom with immune-modulating effects that may be beneficial for people with HIV infection.
Immune-modulating plants that could theoretically be beneficial for people with HIV infection include Asian ginseng, eleuthero, and the medicinal mushrooms shiitake and reishi. One preliminary study found that steamed then dried Asian ginseng (also known as red ginseng) had beneficial effects in people infected with HIV, and increased the effectiveness of the anti-HIV drug, AZT.18 This supports the idea that immuno-modulating herbs could benefit people with HIV infection, though more research is needed.
Traditional Use (May Not Be Supported by Scientific Studies)
Reishi has been used in Traditional Chinese Medicine for at least 2,000 years.19 The Chinese name ling zhi translates as the “herb of spiritual potency” and was highly prized as an elixir of immortality.20 Its Traditional Chinese Medicine indications include treatment of general fatigue and weakness, asthma, insomnia, and cough.21