The Benefits of Shiitake Mushroom

What Should I Know About It?

shiitake mushrooms
Shiitake mushrooms. Rusty Hill/Photolibrary/Getty Images

Shiitake mushroom (Lentinus edodes) is a type of mushroom often consumed as a food in recipes such as soup and noodle dishes. In traditional Chinese medicine, shiitake mushroom is used as a natural remedy for a host of health conditions.

Like other mushrooms, shiitake mushroom contains polysaccharides, a class of carbohydrates thought to influence health. Proponents claim that one type of polysaccharide found in shiitake mushroom, known as lentinan, has unique immune-enhancing properties.

Uses for Shiitake Mushroom

Shiitake mushroom is purported to stimulate the immune system and protect against problems ranging from colds and other infectious diseases to some forms of cancer. Some proponents claim that shiitake can also help lower cholesterol levels and aid in the prevention of heart disease.

Benefits of Shiitake Mushrooms

To date, there is a lack of scientific support for claims of shiitake's health effects. While findings from animal studies and test-tube research suggest that shiitake may offer certain health benefits, few clinical trials have tested shiitake's effectiveness in treating or preventing any condition. Here's a look at some key study findings:

Preliminary research indicates that lentinan may help stimulate the immune system by triggering activity in immune cells (such as B-cells). In a 2011 study, researchers found that shiitake-extracted lentinan given orally to older adults increased the number of B-cells in the blood.

For a study published in 2002, 62 men with prostate cancer took shiitake-containing capsules three times daily for six months. Study results showed that the disease stabilized in only four patients during the treatment period, while 23 patients experienced a progression in their prostate cancer. Given these findings, the study's authors concluded that shiitake extract alone is ineffective as a prostate cancer treatment.

Preliminary research suggests that shiitake may help slow the growth of bacteria that causes tooth decay. In a 2013 laboratory study, scientists discovered that a shiitake mushroom extract inhibited the growth of Streptococcus mutans, the bacteria that forms a sticky, acidic film on teeth that erodes tooth enamel.

Side Effects

Although shiitake mushrooms are widely found in grocery stores, rarely, some individuals may experience a skin reaction to this mushroom known as "shiitake dermatitis." An intensely itchy rash that typically occurs in a linear pattern with swelling and redness, shiitake dermatitis is also called "flagellate dermatitis."

Shiitake dermatitis typically starts 12 to 60 hours after consumption of shiitake mushrooms that have not been fully cooked. The rash often resolves in one to four weeks, but treatment may be required in certain cases. Sun exposure can worsen the rash. Fever, diarrhea, and ulcers inside the mouth may also occur.

When consumed as a food, shiitake mushroom should be cut into bite-sized pieces before it's eaten. Due to it's large size and smooth texture, some people may intentionally or accidentally swallow the mushrooms whole. In a case report, two people ate meals with shiitake mushrooms without cutting them up, which resulted in bowel obstruction requiring medical treatment.

It's important to keep in mind that supplements haven't been tested for safety and dietary supplements are largely unregulated. In some cases, aproduct may be contaminated with other substances such as arsenic. 

Also, the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established. One preliminary study suggests that shiitake mushroom consumption could change the way certain medications are metabolized in the body. You can get further tips on using supplements here.

The Takeaway

Due to the limited research, it's too soon to recommend shiitake as a treatment for any condition. If you're considering the use of a shiitake supplement in the treatment or prevention of a specific health problem, consult your doctor before beginning your supplement regimen. It's also important to note that self-treating a condition and avoiding or delaying standard care may have serious consequences. 

Was this page helpful?
Article Sources