A diagnosis of cancer tells us that a rogue cell group escaped the body’s immune surveillance, and grew up to become a serious medical threat. In most cases, if they are not stopped, they’ll kill their owner…eventually. So, how did these bad apples escape detection? Cancer cells have several ways of eluding the protective interrogation that is constantly asking cells ‘do you belong here?’, with the ongoing eradication of those that don’t fit your normal DNA profile. By whatever means, the successful cancer developed a stealth mode that got it past the immune detection system. Part of this scheme of deception works because the growth process of many tumors is actually quite slow, with the initial cancer cell beginning the journey 10, 20 or even 30 years before the cancer is large enough to be diagnosed.1 Now that’s a scary thought, isn’t it? The abnormal changes may not be ‘just enough different’ in the early stages to engage immune system suspicions. What’s also concerning is that as many as 75% of cancers have already spread (metastasized) before they are diagnosed 1, even if the doctor happily informs you that ‘we got it all’ in surgery or subsequent early therapy. This prompts the question of what we can do to help the immune system to better recognize abnormal cells, at whatever their stage of growth? This may be just as important for those who don’t think they have cancer, as for those who have been recently diagnosed, and even more so for those who hope that they are ‘out of the woods’ after cancer treatment.
Introducing the immune system Special Forces cell, it’s a natural born killer
About 2% of our immune cells have the function of identifying cells carrying viruses, or early developing tumor cells. These are known as natural killer, or NK cells. They look for cell markers that express ‘the genetic expression of self’. When they find a ‘non-self’ expressing cell, like an evolving cancer cell, the NK cell injects it with protein dissolving granules that cause the abnormal cell to auto destruct. People who are genetically or situationally predisposed to low NK activity may develop cancer more rapidly. The evidence shows that enhancing NK activity can fight both viruses, like influenza, as well as emerging or established cancer cell lines. These ‘natural killer’ cells get their name from their ability to recognize virus or cancer without having to draw on memory from a previous exposure. You don’t have to wait for a second cancer for these cells to jump right into action.
Choosing NK activity support wisely
At this point it would be great to move on and give you a few natural ways to enhance your NK cell activity. But there’s a catch. There are a few medical problems where NK cells may benefit from stimulation, but also where another part of the immune system which governs the T cells is already overactive. Collectively we think of overactive T cells as the autoimmune disorders, but it’s even a little more complicated than just that. These conditions are divided even further as to which part of the T cell activity is misdirected. We call these Th1 or Th2 dominant states. Some forms of NK stimulation can aggravate either one of these states, and in the process, unnecessarily provoke one’s underlying medical problem. The most common of these conditions include:
Th1 dominant states
-Type I diabetes
-Chronic viral infections like hepatitis, EBV or HIV
Th2 dominant states
-Allergic Dermatitis and serious allergy disorders
-Atopic dermatitis and eczema
-Multiple chemical sensitivity
It is important, even critical to recognize that advice about stimulating NK cells for individuals with these conditions will vary somewhat compared to those who do not have them. While the remainder of this article discusses strategies for enhancing your NK killer cells, particularly if you have cancer or are at elevated risk for cancer, it will also detail what not to do if you fall into the diagnostic categories listed above.
I’ll list four categories, starting with measures that everyone can do. Then we’ll go on to NK enhancing measures that should be used with discretion by those with either a Th1 or Th2 dominant condition; and then some additional measures you can add if you do not have one of these Th1/Th2 conditions and related nutrient stimulant restrictions. Keep in mind that Th1/Th2 dominance is relative, sometimes you may benefit from T cell testing that can quantify these factors. And just because you have a condition does not mean that some of the nutrients mentioned may not have benefits for you if taken at regular or lower doses.
Things you can do to enhance NK cell activity no matter what your health status:
-Take daily probiotics. Supporting bowel flora influences the 70% of the immune system that surrounds the bowel, and enhances NK activity 2
-Vitamin C enhances NK activity, and it doesn’t require mega doses. 1000 mg/day is enough to see benefits.
-regular moderate exercise stimulates immune function, including NK function.
-adding blueberries to your diet, although maximal benefits need amounts in the range of 1 cup/day. 3 Black pepper also enhances NK cell activity. In both cases it may be challenging to ingest enough to be maximally helpful, but adding some to your diet may be worthwhile for the anti-oxidant benefits they provide, as well.
-consider taking sea cucumber extract. Compounds found in sea cucumber activate NK cell activity. In addition, they have been found to inhibit metastasis and tumor angiogenesis (which allows cancers to feed themselves). 4 In vitro studies (test tube, not in live humans) showed that Frondoside A, found in sea cucumber, was active against 95% of ER+ breast cancer cells, 95% of liver cancer cells, 90% of melanoma cells, and 85+% of three different types of lung cancer. Additional studies showed that Frondoside A was as effective as chemotherapy in killing these cancer cells. Keep in mind that studies have yet to substantiate these effects long term in humans with cancer. Nonetheless, on the NK activation benefit alone, this may be worth consideration. A typical dose would be 2000 mg of the powdered extract or 2 cc of the tinctured extract per day.
Note well that although there may be adjunctive benefit from these nutrients, that one should not consider sea cucumber or any of these supplements as front line or stand alone therapy for cancer or other medical disorders.
If you have a Th1 dominant disorder:
-be cautious with the use of high or prolonged dosages of astragalus, echinacea and medicinal mushroom extracts like maitake and beta-glucan, which are used at times as immune boosters, and may aggravate Th1 dominant problems.
If you have Th2 dominant disorders:
-be cautious about using high doses of potential immune boosters including antioxidants like green tea extracts, pine bark extracts (also known as Pycnogenol), quercitin, resveratrol, or anti-inflammatories such as curcumin or white willow extract as they can provoke the Th2 dominance.
Additional options for those without the listed restrictions:
If you do not have a Th1/Th2 related autoimmune disorder, you can use any of the measures mentioned above. However, I consider the mushroom extract family as front line therapy to boost NK cell function. Studies show that these glyconutrients can raise NK activity up to three times baseline. I know of three versions with a reliable track record, and I’ll list them in the order of my preference from clinical experience:
-RM-10, which is the brand version for a ten Maitake extract version from Garden of Life: one cap twice daily
-AHCC: 1000 mg twice daily
-turkey tail mushroom extract: 1500-2000 mg/day
Finally, I’ll mention one other natural product that stimulates NK activity, known generically as “enzymatically modified rice bran.” A study of 48 patients with multiple myeloma, median age 65 years, found that a dose of 2,000 mg/day for three months produced an 84% increase in NK cell activity by the end of the second month of supplementation.4 MGN-3 was used in this study, and it is a commonly used version of modified rice bran.
Use your natural killer cells to finish the job
If you have cancer, or are at higher than average risk, consider one or more of these natural measures to enhance your ‘natural cancer killers’. Even if you employ conventional medical measures to reduce the tumor burden, it is useful to remember that the final remnants of any cancer cannot be completely eradicated by surgery, chemo or radiation, short of killing the patient as well. In the final analysis, your immune system will be required to do the mop up work of finding and clearing any surviving cancer cells. Optimize your odds by helping your natural born killers to do their job!
1 Friberg, Sten and Mattson, Stefan Journal of Surgical Oncology 1997;65:284–297 REVIEW ARTICLE: On the Growth Rates of Human Malignant Tumors: Implications for Medical Decision Making Department of General Oncology, Radiumhemmet, Karolinska Hospital, and WHO Collaborating Centre For Urologic Research, Stockholm, Sweden
2 Gill HS1, Rutherfurd KJ, Cross ML. J Clin Immunol. 2001 Jul;21(4):264-71. Dietary probiotic supplementation enhances natural killer cell activity in the elderly: an investigation of age-related immunological changes.
3 Attoub S1, Arafat K, Gélaude A, et.al. Frondoside a suppressive effects on lung cancer survival, tumor growth, angiogenesis, invasion, and metastasis. PLoS One. 2013;8(1):e53087. doi: 10.1371/journal.pone.0053087. Epub 2013 Jan 8.
4 McAnulty LS, Nieman DC, et.al. Effect of blueberry ingestion on natural killer cell counts, oxidative stress, and inflammation prior to and after 2.5 h of running. Appl Physiol Nutr Metab. 2011 Dec;36(6):976-84. doi: 10.1139/h11-120. Epub 2011 Nov 23.
5 Cholujova D, Jakubikova J, Czako B, et al. MGN-3 arabinoxylan rice bran modulates innate immunity in multiple myeloma patients. Cancer Immunol Immunother. 2013 Mar;62(3):437-45.