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Natural Killer Cells are high and low in a variety of conditions.  They can contribute and prevent disease.  Do YOU have low or high Natural Killer Cells?


Intro to Natural Killer (NK) Cells

Natural Killer (NK) cells are a type of toxic lymphocytes that are critical to the immune system (R).

NK cells are produced in the bone marrow, lymph nodes, spleen, tonsils, and thymus, where they then enter into the circulation (R).

They control several types of tumors and microbial infections by limiting their spread and future tissue damage that can occur (R).

The cells become active around 3 days after infection and respond to tumor formation in the body (R).

NK cells monitor tumors that may grow by directly triggering the death of tumor cells(R).

They have the ability to recognize stressed cells without having to have a previous exposure to the pathogens (R), allowing for a fast immune reaction (R).

NK cells can develop long-lived and highly specific memories to a variety of targets (R).

Extreme genetic diversity is present in both mice and humans coding for NK cells (R).

What Function Do Natural Killer Cells Have?


Individuals lacking NK cells have regular viral infections and die prematurely (R).

Individuals deficient in NK cells are prone to early phases of herpes virus infection (R) and NK cells help fight HIV (R).

Mice with less NK cell function are more prone to cancers (R).

Activation of NK Cells

Circulating NK cells remain in their resting phase. NK cells activated by cytokines lead to the invasion of these cells into tissues with pathogen-infected cells (R).

When activated, they secrete cytokines such as interferons (R) and TNF-a (R).

NK cells release a membrane-disrupting protein, perforin, which causes cell death of the target cell (R).

So perforin perforates the “skin” of the pathogen (R).

Conditions With Elevated Natural Killer Cells

Obesity promotes the expression of inflammatory genes in the abdominal fat.

It elevates the number and activity of NK cells in only the stomach fat (R).

When NK cells are removed, inflammation in abdominal fat is suppressed and insulin resistance is improved (R).

NK cells control insulin resistance by transmitting proteins that affect macrophages(R).

In Asthma, NK cells contribute to IgE mediated immune-responses and may exacerbate the condition (R).

In Type 1 diabetes, NK cells increase the destruction of the pancreas (R).

Higher NK cells form in women who have reoccurring miscarriages (R).

Th1 Dominance and NK Cells

Th1 dominance (IL-12, IL-2) increases NK Cell activity (R).

On the other hand, NK cells may, in turn, destroy and suppress Th1 cells (R).

I actually don’t do very well with the more potent stimulators of NK Cells.  This could either be because I don’t do well with NK cell stimulants, or because NK Cell stimulators have other immune boosting properties – or both.

Conditions That Have Low Natural Killer Cells


Impairment of Natural Killer cells is also associated with advanced aging (R).

Natural Ways to Increase Natural Killer Cells

These strategies lead to increased natural killer cells.




Natural Ways to Enhance Natural Killer Cell Function

These strategies lead to increased function or cytotoxicity of Natural Killer Cells.


  • Exercise (R)
  • Strength training (R)
  • Antioxidants (R)
  • Massage therapy (R)
  • White button mushrooms (R)

Supplements (if overactive immune system)

These supplements are safe if you are Th1 dominant and have an overactive immune system, but you’d still like to stimulate NK Cells.

Supplements (if underactive immune system)

Other: LSD (R)


NK Cell Inhibitors

  • Lectins initiate excess polyamine production, which may be the result of an effort to repair the damage to intestinal microvilli caused by lectins (R).  A high polyamine level may decrease NK cell populations (R).
  • Lipoic Acid (R)
  • CRH/ACTH/Cortisol (R– from stress or other causes
  • Indoleamine 2,3-Dioxygenase (IDO) – activated from cortisol and inflammation (R)
  • Folic acid (synthetic form) (R)
  • Somatostatin (Growth Hormone–Inhibiting Hormone) (R)

NK Cell Cytotoxicity Inhibitors

FDA Compliance

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.


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  • B.C.

    You’re wrong, patients with M.E( PwME). have a decreased number of NK cells, and their functions are abnormally low too. You can even correlate the severity of a PwME, with that data. Source : chairs of ME Research.

  • Christina

    ME/CFS is a very complex illness and different for everyone. Please see the latest Australian research discovery relating to NK cells, blocked ion channels and calcium. see Health Rising for more info.

  • Vasra

    I get HSV1 cold sores out break almost immediately after starting to use spirulina (source/quality/form/brand does not matter at all). spirulina (dried, raw) has a c. 1.38 ratio of lysine to arginine, so this is not a surprise.

    Almost all supplements, foods and sources that seriously ramp up _relative_ (not absolute) arginine levels, cause a cold sores , or at worst, a shingles outbreak.

  • angela coral eisenhauer

    I like the page, though, hope you dont mind me correcting you. MS has low NK cells, ME / CFS has high NK cells. Happy to send you my results, but waiting on more information. I have read that reference, many times.

    1. J.T.

      I have ME/CFS, and the research shows those that have it have low or impaired NK Cell Function (not count). To that end, there is Ampligen. It has been in FDA trials at several expert clinician’s offices going back over 20 years. It boosts NK cell function using the Toll-Like Receptor 3 pathway. The LOW NK cell function is why many w/ ME/CFS have active viral infections. If you have ME/CFS, I’m sorry. It really, really sucks!

      1. angela coral eisenhauer

        Co I could have very high NK, which I have, but they are not working, so Ampligen would help?

  • angela coral eisenhauer

    Your reference, re CFS having reduced Natural Killers cells? PLEASE re read your reference, CFS has HIGH NK cells. I know because I have it, and you have totally misunderstood your own reference.

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