Written by Erin Chamerlik, Nutrition Educator, MS, MT(ASCP)
Natural Killer
Cells (NK cells). Not something we talk about everyday, or any day, but these
little white blood cells are your friends because they are your
front line of defense against cancer and this winter's germs, including
those that cause colds, flu and pneumonia.
When cells are
infected by a virus or changed into cancerous cells, NK cells attack
causing the rogue cell to die (apoptosis).
Here's the bad
news. Like so many things in the body, NK cells lose their functionality as we
age. The good news is that we can optimize our NK cell function with a few
simple improvements.
There are a
few strategies that you can employ to help strengthen your immune system and
increase the function of NK cells, your immune system’s front line
fighters.
Increase DHEA
DHEA,
(dehydroepiandrosterone), produced and metabolized in the adrenal glands,
gonads, and dermis, has the abilityto improve the immune system (and many other
things) when blood levels of the important hormone precursor are increased to
more youthful levels. After age
25, DHEA levels decline at the rate of about 2% per year. Some unwanted signs
of low DHEA include low libido, low energy, poor memory, increased belly
fat, weight gain and a sub-optimal immune system.
It is
important to maintain DHEA levels because DHEA has immune-enhancing effects and
increases the NK cells. 1,
2
A study of men taking DHEA for five
months was conducted by Dr. Omid Khorram of the University of Wisconsin. The
results were described in Dr. William Regelson in his book, The
Super-Hormone Promise.
Regelson wrote,
"Dr. Khorram found that DHEA did indeed have a palpable, measurable
rejuvenating effect on their aging immune systems." He found that
DHEA geared up the immune system to fight foreign invaders and
specifically DHEA "increased the number and activity of
cancer-fighting NK (natural killer) cells, which keep a watchful eye on
potential cancerous cells and destroy them before they can grow.” 3
DHEA helps the
immune system in another way, by providing a counterbalance to stress. The body
responds to stress by producing more of the adrenal hormone cortisol. When
stress is not managed, large amounts of cortisol reduce the number and function
of NK cells. 4
It is important
to maintain youthful levels of DHEA to feel and look your best and help reduce
the negative effects cortisol can have. Adults over age 25 can safely benefit
from topical application of bioidentical DHEA cream, Twist 25.
NK Cell Boosting
Foods and Supplements
Foods and
supplements that increase beneficial NK cells will help bolster your front line
defense against newly arising infected cells and malignant cells.
The following foods and supplements have
been shown to have a positive impact on NK cells:
•
Dark
Chocolate and Cacao 5
• Panax
ginseng 6
•
Blueberries 7
•
Aged
Garlic 8
•
Vitamin
E 10
•
Foods
high in beta carotene - carrots, dark green leafy vegetables and sweet potatoes
10
Factors Known
to Reduce NK Cell Activity
Just as we want
to add beneficial foods and supplements to support our first line fighters, it
is wise to address negative influencers too.
These factors
negatively affect NK cell function:
• Micronutrient deficiencies in zinc or
vitamins A, C, and D 11, 12
• Exposure to toxins 12
• Obesity 12
• Smoking 12
• Certain medications 12
• Lack of adequate sleep 13
In this article,
we have only addressed factors that directly affect the NK cells of the immune
system. Supporting the immune system begins with a strong foundation of
healthy, unprocessed food, clean, filtered water, and adding supplements like
Vitamin C, Omega-3 Fish Oil, Vitamin D3 + K2, and probiotics. Regular exercise
is important year-round, but may be even more important in winter to keep your
immune system strong.
References
1.
Bovenberg SA, van Uum SH, Hermus AR. Dehydroepiandrosterone
administration in humans: evidence based?
Neth J Med. 2005 Sep;63(8):300-4. Review. PubMed PMID: 16186639.
2.
Khorram O, Vu L, Yen SS.
Activation of
immune function by dehydroepiandrosterone (DHEA) in age-advanced men. J Gerontol A Biol Sci Med Sci. 1997 Jan;52(1):M1-7. PubMed PMID:
9008662.
3.
Regelson W. The
Super-Hormone Promise. New York, NY: Pocket Books; 1997. 400p.
4.
Andersen BL, Kiecolt-Glaser JK, Glaser R. A
biobehavioral model of cancer stress and disease course. Am Psychol. 1994 May;49(5):389-404. Review. PubMed PMID:
8024167; PubMed Central PMCID: PMC2719972.
5.
Kamei M, Nishimura
H, Takahashi T, Takahashi N, Inokuchi K, Mato T, Takahashi K. Anti-influenza
virus effects of cocoa. J Sci Food
Agric. 2015 Apr 2. doi: 10.1002/jsfa.7197. [Epub ahead of print] PubMed PMID:
25847473.
6.
Kang S, Min H. Ginseng,
the 'Immunity Boost': The Effects of Panax ginseng on Immune System. J Ginseng Res. 2012 Oct;36(4):354-68. doi:
10.5142/jgr.2012.36.4.354. PubMed PMID: 23717137; PubMed Central PMCID:
PMC3659612.
7.
McAnulty LS, Nieman DC,
Dumke CL, Shooter LA, Henson DA, Utter AC, Milne G, McAnulty SR. 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. PubMed PMID:
22111516.
8.
Ishikawa H, Saeki T,
Otani T, Suzuki T, Shimozuma K, Nishino H, Fukuda S, Morimoto K. Aged garlic extract prevents a
decline of NK cell number and activity in patients with advanced cancer. J Nutr. 2006 Mar;136(3
Suppl):816S-820S. PubMed PMID: 16484572.
9.
Stamets P. Turkey Tail
Mushrooms Help Immune System Fight Cancer. [Internet]. HuffPost2012 June.
Available from: Turkey Tail Mushrooms Help Immune System Fight Cancer.
10.
Ashfaq MK, Zuberi HS, Anwar Waqar M. Vitamin
E and beta-carotene affect natural killer cell function. Int J Food Sci Nutr. 2000;51 Suppl:S13-20. PubMed PMID:
11271852.
11.
Erickson KL, Medina EA, Hubbard NE. Micronutrients
and innate immunity. J Infect Dis. 2000
Sep;182 Suppl 1:S5-10. Review. PubMed PMID: 10944478.
12.
Bush B, Mo S. Natural killer cells –
Canaries in the immunological coal mine. [Internet].
https://neuroendoimmune.wordpress.com2011 May. Available from:
https://neuroendoimmune.wordpress.com/2011/05/08/natural-killer-cells-canaries-in-the-immunological-coal-mine/.
13.
Irwin M, McClintick J,
Costlow C, Fortner M, White J, Gillin JC. Partial night sleep deprivation
reduces natural killer and cellular immune responses in humans. FASEB J. 1996
Apr;10(5):643-53. PubMed PMID: 8621064.
About the Writer
Erin Chamerlik is the founder of Get Better Wellness, Inc., a wellness-focused health
and nutrition education company
located in Nashville, TN. Learn how you can reach optimal health through a
whole food eating plan that integrates ancient wisdom with an innovative,
science-based approach to health and wellness.
Erin extends her message through podcasts,
public workshops, social media (Twitter, FaceBook, Pinterest and Instagram) and
she blogs at GetBetterWellness.com
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