Study: Turkey Tail and Polysaccharide-K (PSK)
The National Library of Medicine published a study on Turkey Tail mushrooms and other medicinal mushrooms. The publication outlines the benefits of polysaccharide-K, a unique polysaccharide found in Turkey Tail mushrooms.
The study is introduced answering the following questions:
Questions and Answers About Turkey Tail and Polysaccharide-K (PSK)
- What is turkey tail?Turkey tail is a type of mushroom that grows on dead logs worldwide. It's named turkey tail because its rings of brown and tan look like the tail feathers of a turkey. Its scientific name is Trametes versicolor or Coriolus versicolor. In traditional Chinese medicine, it is known as Yun Zhi. In Japan, it is known as kawaratake (roof tile fungus). There are many other types of Trametes mushrooms. It can be hard to tell the difference between turkey tail and other types of Trametes mushrooms without the use of special testing.
- What is PSK?
- How is PSK given or taken?PSK can be taken as a tea or in capsule form.
- Have any laboratory or animal studies been done using PSK?In laboratory studies, tumor cells are used to test a substance to find out if it is likely to have any anticancer effects. In animal studies, tests are done to see if a drug, procedure, or treatment is safe and effective in animals. Laboratory and animal studies are done before a substance is tested in people.Laboratory and animal studies have tested the effects of PSK on the immune system, including immune cells called natural killer cells and T-cells. For more information on laboratory and animal studies done using PSK, see the Laboratory/Animal/Preclinical Studies section of the health professional version of Medicinal Mushrooms.
- Have any studies of PSK been done in people?
This excert tells us a lot about the science and history of Turkey Tail mushrooms and gives us a glimpse into the thesis of the science being reported.
Outlining the affects of Polysaccharide-K in cancer treatment, the article continues by addressing specifically gastric, breast and lung cancers.
Gastric cancerStudies show that the use of PSK as adjuvant therapy in patients with gastric (stomach) cancer may help repair immune cell damage caused by chemotherapy and strengthen the immune system.Studies of PSK as adjuvant therapy for gastric cancer include the following:
- A randomized clinical trial in Japan done between 1978 and 1981 included 751 patients who had surgery for gastric cancer. After surgery, patients received chemotherapy with or without PSK. On average, the patients who received chemotherapy and PSK lived longer than those who received chemotherapy alone. The researchers believe it might be possible to predict which patients would benefit the most from PSK depending on the numbers of granulocytes and lymphocytes in the patient’s blood.
- In 1994, a study in Japan followed 262 patients who had successful surgery for gastric cancer and were given chemotherapy with or without PSK. Patients who received chemotherapy and PSK were less likely to have recurrent cancer and lived longer than those who did not. Treatment with PSK caused few side effects. The researchers thought the study showed that PSK and chemotherapy should be given to gastric cancer patients after surgery to remove the cancer.
- A review published in 2007 combined results from 8 randomized controlled trials in 8,009 patients who had surgery to remove gastric cancers. After surgery, patients in the trials were given chemotherapy with or without PSK. The results suggest that receiving chemotherapy and PSK helped patients live longer after surgery.Breast cancerTo date, PSK studies in patients with breast cancer have focused on changes in the immune system (T-cell and B-cell levels in the blood) rather than on clinical results (patient survival, symptoms, side effects, and quality of life).Colorectal cancerStudies of PSK as adjuvant therapy for colorectal cancer include the following:
- PSK was studied in a randomized clinical trial for its effect on the immune system in patients with stage II or stage III rectal cancer. Patients received chemotherapy and radiation therapy, with or without PSK. This study found that PSK increased the number of cancer-killing immune cells and had anticancer effects in tissue that received radiation therapy.
- A review that combined results from 3 studies in 1,094 patients with colorectal cancer found that patients who received PSK were less likely to have recurrent cancer and lived longer than those who did not.Lung cancer
Studies of PSK as adjuvant therapy for patients with lung cancer include the following:
- Five nonrandomized clinical trials reported that patients treated with PSK and radiation therapy with or without chemotherapy lived longer.
- Six randomized clinical trials in patients with lung cancer studied chemotherapy with or without PSK. The studies showed that patients who received PSK improved in one or more ways, including immune function, body weight, well-being, tumor-related symptoms, or longer survival.
The article gives us an idea of the impact of the benefits of Turkey Tail and mentions that there have been few reported side affects throughout the available literature on polysaccharide-K.
Though this publication is new, the science is thorough, extensive and draws from several sources to provide its conclusions. We are able to draw conclusions about the incredible nature of Turkey Tail and it's capacity to help the lives of those affected by cancer and other ailments.
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