Does turkey tail mushroom extract help against cancer?
Turkey tail mushroom extract shows the most evidence for a modest survival benefit alongside chemotherapy in stomach cancer. For lung and colorectal cancer the signals are positive but less certain.
The most thoroughly studied compound is a extract from the turkey tail mushroom that has been used alongside chemotherapy in Japan for decades. In stomach cancer, eight studies involving more than 8,000 patients combined show that it clearly improves survival after surgery to remove the tumour. The ratio was 0.88, which amounts to a modest but consistent benefit across all studies.
In colorectal cancer the picture is more nuanced. Three studies with a total of 1,094 participants found a small positive effect on five-year survival: on average, 16 patients would need to be treated to see one additional survivor. The researchers themselves rate this evidence as low certainty, partly because the chemotherapy regimens used in those studies no longer match current standard treatment.
In lung cancer, most studies showed positive effects on survival and immune function, but the results are not consistent across all outcomes. Here too, the researchers consider the current evidence insufficient to make broad recommendations.
For side effects of chemotherapy, such as nausea, diarrhoea and fatigue, seven studies in colorectal cancer found no demonstrable difference between the turkey tail extract and a dummy treatment. The researchers rate that evidence as very low certainty. Across all studies examined, no serious safety concerns with the extract were reported.
A separate line of research involves a vaginal gel based on turkey tail mushroom for women with a certain type of HPV who have early-stage cervical changes. An expert consensus reports possible positive effects on healing of those changes and clearing the virus, but several authors received fees from the manufacturer. Independent studies on this are not yet available, so for now this is no more than a preliminary signal.
This answer draws on five broad overviews of the research, one of which combined results from eight studies in stomach cancer (more than 8,000 patients). The authors of the colorectal cancer overview rated the evidence on side effects as very low certainty for all outcomes, and the evidence on survival as low certainty. For the cervical gel there is a conflict of interest: several authors were paid by the manufacturer, and independent research is not yet available. The evidence is strongest and most consistent for stomach cancer; for lung and colorectal cancer it is positive but thinner and less certain.