Shiitake is a medicinal mushroom used as a natural remedy for a host of health conditions. Long used in traditional Chinese medicine, shiitake is said to boost the immune system and protect against problems ranging from the common cold to cancer. Proponents claim that shiitake can also help treat infections (such as a hepatitis), lower cholesterol levels, and aid in the prevention of heart disease.
The Science Behind Shiitake's Health Benefits
To date, there is limited 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:
1) Shiitake and Colon Cancer
Shiitake contains lentinan, a type of beta glucan (an immune-enhancing substance found in other medicinal mushrooms, including maitake). Laboratory research indicates that lentinan may help stimulate the immune system by triggering activity in immune cells (such as natural killer cells and T-cells). In a 2002 study on mice, researchers found that shiitake-extracted lentinan helped hinder the animals' development of colon cancer.
2) Shiitake and Prostate Cancer
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.
3) Shiitake and Cavities
Preliminary research suggests that shiitake may help stop tooth decay. In a 2000 study on rats, scientists discovered that shiitake-fed animals were less likely to develop cavities (compared to rats that weren't fed shiitake).
Is Shiitake Safe?
Although shiitake is generally considered safe when taken in supplement form, there's some evidence that long-term use of shiitake may lead to dermatitis.
Sold fresh or dried in most grocery stores, whole shiitake mushrooms can safely be used in cooking. However, little is known about the health benefits of consuming shiitake as a whole food.
Should You Use Shiitake for Health Purposes?
Due to the lack of scientific support for shiitake's health effects, it's too soon to recommend the use of shiitake for health purposes. If you're considering the use of a shiitake supplement in treatment of prevention of a specific health problem, consult your doctor before beginning your supplement regimen.
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