Turkey tail is a wild mushroom found throughout the world whose fan like shape and coloring resembles the tail of a wild turkey. Like all medicinal mushrooms, turkey tail contains polysaccharides called beta-glucans that can activate receptors on immune cells initiating an immune response.
Specifically, beta-glucans activate dectin-1 on specialized immune cells called dendritic cells. Dectin-1 is a pattern recognition receptor involved in sensing foreign components and initiating an immune response. These foreign patterns can come from viruses, bacteria, fungi, or even the mutated components of cancer cells. Dectin-1 activation can also occur on other immune cells including monocytes and macrophages (see figure https://pmc.ncbi.nlm.nih.gov/articles/PMC7277906/), but this article will focus on dendritic cells.
Dendritic cells are known as professional antigen-presenting cells. They are part of the adaptive immune system and are meant to initiate an immune response to eradicate specific foreign invaders. Once activated, dendritic cells process and present the foreign patterns known as antigens to “cell killing” cytotoxic T cells, effectively instructing them on what to kill, and this can include malignant cancer cells.
Immune stimulation against foreign invaders is part of the rationale behind the cancer fighting qualities of turkey tail. This is also why many pet owners give their pooches turkey tail to avoid getting cancer. The idea is to stimulate a strong immune response by adding foreign patterns into a situation in which the body is not mounting an effective response against cancer cells. Humans aside, please purchase our turkey tail tincture for man’s best friend. However, unlike dogs, human cancers are more complex. They progress in a way the immune system actually ignores them.
But why would the body’s natural immune system ignore the foreign patterns on cancer cells?
Let’s first define cancer simply as uncontrolled cell growth, and then slowly build in complexity to understand this phenomenon. Cancer cells accumulate mutations known as driver mutations that allow them to block exterior signals that tell them to stop growing, and bypass internal signals that allow them to divide endlessly. These mutations occur in genes known as tumor suppressor genes and oncogenes, respectively.
Now let’s add to this model. Cancer cells further develop mutations that allow them to put up signals to the immune system to turn it off. For example, cancer cells often upregulate a molecule called PD-L1 that essentially shuts off T cells that come near them. They also progress in a manner that down-regulates the amount of “foreign” patterns or antigens that they display on their surface allowing them to fly under the radar of immune surveillance. This leads to what is known as the immunosuppressive tumor microenvironment (TME). They are camouflaged against the immune system.
Adjuvants in cancer treatments act as extra immune stimuli that can overcome this trickery by cancer cells. That’s exactly what turkey tail can do. It arms the immune system to full power so that the “cell killing” cytotoxic T cells can target and eradicate tumors without being shut down. However, adjuvants are secondary treatments. As I mentioned, cancer cells down regulates the foreign antigens. So even a fully armed immune system cannot recognize them.
How can we overcome this?
If a cancer patient undergoes a primary treatment like radio- or chemotherapy, it will kill a certain amount of the cancer cells. These dead cells will spill out their foreign patterns. At this time, if the patient is given turkey tail, their immune system will pick up these patterns with the added immune stimulation that the turkey tail provides. The damaged tumor will display more of the foreign patterns allowing the fully armed immune system to attack locked and loaded, killing any remaining cancer cells and preventing relapse. In this context, turkey tail does not directly eliminate established tumors but rather helps the immune system finish the job, but we’ll revisit this in a moment. Another key factor is that patients undergoing radio- or chemotherapy are immune compromised as these therapies kill the patient’s immune system in addition to the cancer cells. Therefore, turkey tail can actually help restore the immune system in patients when they are most vulnerable.
Now let’s talk about what makes turkey tail even more potent in this regard and how turkey tail can DIRECTLY kill cancer cells. The beta-glucans that are found in turkey tail are actually quite unique. The two most well studied are polysaccharopeptide (PSP) and polysaccharide Krestin (PSK). These are essentially beta-glucans bound to a protein substrate (think P or K). This increases their molecular weight and complexity. Increased molecular weight allows them to remain in the body longer, thus increasing their ability to enhance anti-cancer immunity. Moreover, the protein components have direct cancer killing qualities.
For example, PSK from turkey tail was shown to have direct cell-killing effects against different cancer cell lines derived from leukemias, melanomas, fibrosarcoma, and cervical, lung, pancreatic, and gastric cancers via arrest of the cell cycle (https://pmc.ncbi.nlm.nih.gov/articles/PMC2291471/). A more recent study also confirmed the induction of human melanoma cell death (https://pubmed.ncbi.nlm.nih.gov/36827712/). PSK is already approved as an adjuvant therapy in Japan further underscoring its recognition as a potent cancer fighter. Here, it is important to note that PSK is only found in the mycelium of turkey tail. The mycelium of a mushroom is the component below the surface. This is in contrast to the fruiting body, which is the visible part of the mushroom that we more often visualize.
Here at Brain Wave, we believe in the power of mycelium. Thus, all of our turkey tail products, as part of the gummies or as a tincture, utilize both the fruiting body and mycelium so you know you’re getting that PSK. Given the strength of the evidence supporting turkey tail in fighting cancer, I hope all who experience this devastating disease consider it as a viable option in their treatment plans.
Til next time,
Dr. Andy