Reishi Mushroom: An Evidence-Based Overview of Medicinal Benefits and Uses

Reishi mushroom (Ganoderma lucidum) has been a revered medicinal fungus in traditional Chinese and Japanese medicine for centuries, often referred to as the "mushroom of immortality." Its broad range of purported health benefits is attributed to its diverse bioactive compounds, including polysaccharides and triterpenoids, which have been the focus of extensive research.

1. Immune System Support

Reishi is widely known for its ability to modulate the immune system. The polysaccharides and other compounds found in the mushroom have been shown to influence the genes of white blood cells, which are crucial components of the immune response. In both test-tube and animal studies, Reishi has been found to enhance the activity of various immune cells, such as natural killer (NK) cells and macrophages [6, 7]. This immunomodulatory effect may help the body fight off infections and diseases.

2. Potential Anti-Cancer Effects

A significant amount of research has been conducted on Reishi's potential role in cancer. While it is not considered a stand-alone cancer treatment, studies suggest it may be a beneficial supplement to conventional therapies.

Inhibition of Cancer Cells: Laboratory and animal studies have shown that Reishi extracts and spores can inhibit the growth of various cancer cells, including those of the colon, breast, prostate, and liver [6, 8, 9].

Support for Cancer Patients: A review of clinical trials found that Reishi could be administered as an adjunct to conventional treatment, as it has the potential to enhance a patient's immune response and improve their quality of life [10]. However, there is insufficient evidence to suggest it prolongs long-term survival.

3. Stress, Fatigue, and Mood

Reishi is often classified as an adaptogen, an herb that helps the body cope with stress.

Fatigue and Depression: Some studies have indicated that Reishi may help reduce fatigue, anxiety, and depression. A study on people with neurasthenia, a condition associated with fatigue and irritability, found that taking a Reishi supplement for eight weeks significantly improved their sense of well-being and reduced their fatigue [11].

4. Heart Health and Blood Sugar Control

Preliminary research suggests that Reishi may have a positive impact on cardiovascular and metabolic health, although the evidence is mixed and more human studies are needed.

Heart Health: Animal and in-vitro studies have found that Reishi may help decrease blood sugar and triglycerides and increase "good" HDL cholesterol [12]. However, human studies on its effects on cholesterol have been inconsistent.

Blood Sugar Management: Some animal studies suggest that certain compounds in Reishi may help lower blood sugar levels. However, a human study found no significant effect of Reishi supplementation on fasting blood sugar or long-term blood sugar markers [13].

5. Other Potential Benefits

Reishi also contains a wide array of antioxidants and may have a hepatoprotective effect, helping to protect the liver from damage [6, 14]. Additionally, some research has explored its antiviral and antibacterial properties [15].