15+ Ways to Naturally Boost Immunity
Improving and boosting your immunity is critical for several basic reasons.
First of all, if you're sick you can't exercise and exercise is a fountain of
youth. Secondly, being sick all the time effects your attitude and your
sex life, both of which in turn can effect your testosterone and hormones.
Finally, chronic infection is associated with increased inflammation levels
potentially leading to heart disease, dementia and a host of other maladies. So
you've got to stay healthy by improving your immunity naturally.
Of course, our frantic, fragmented chaotic lifestyles make this seem difficult
for many of us. We feel sick and run down almost all the time - especially
through the cold and flu season.
Well, as usual, I have good news: you can boost your immunity naturally.
I have made dramatic improvements in this area of my life as I was always one of
those people who caught every bug floating in the air. Now I will
occasionlly get a cold or flu, but even then my symptoms are almost non-existent.
In fact, 2008/2009 is the first year I can say that I had
no real colds or flus. And, most importantly,
it rarely effects my ability to work and exercise.
Below are 12 Ways to Boost Your Immunity based, of course, on the latest
1) Vitamin C. It is interesting because some health food and vitamin
supplement manufacturers like to tout
Vitamin Cas the ultimate immune-boosting
supplement. However, this is questionable at best. For every study
Vitamin C boosting immunity in some way, there is
another that shows the opposite.  That said,
Vitamin C can still be recommended
for colds and flus. Why?? Because human studies do show that Vitamin
C lowers the symptoms of colds in particular.  Usually, you are simply waiting for a cold to
run its course without completely taking you out of commission as far as work,
exercising and so on. Well,
Vitamin C can help in that regard.
2) Low Fat Diet. Several studies have found that a
Low Fat Diet boosts immunity when compared to the
immunity on a typical Western Diet.  One very interesting study on
hyperlipimic patients found that their immunity was boosted on a relatively
(15%) Low Fat Diet even though calories were reduced.  The same
phenomenon has been observed in animal studies as well. Again, I was
shocked at how healty I felt when I went on a
Low Fat Diet.
3) Sleep. Many studies on animals and humans have verified that sleep is
critical for immune function (and testosterone by the way). For example,
2009 study looked at 153 healthy adult men and women and actually infected
them with cold viruses. Those who slept longer and better were MUCH more
resistant to the colds.  Let me quote from the study: "Participants with less
than 7 hours of sleep were 2.94 times more likely to develop a cold than those
with 8 hours or more of sleep. The association with sleep efficiency was also
graded: participants with less than 92% efficiency were 5.50 times more likely
to develop a cold than those with 98% or more efficiency". See this link on Sleep for more information as well.
4) Tea. Tea activates your body's T cells
through L-theanine, an amino acid found in tea. T cells are your first
line of definse against bacterias and viruses. Furthermore, this leads to
increased interferon output.  This is like taking away a pen knife and
arming your immune cells with RPG's instead.
5) American Ginseng. One recent,
of North American Ginseng used a 80% 200 mg extract and found that Ginseng
improved outcomes on colds by almost every standard measure: it decreased
the # of colds, the number of people catching two or more colds, cold symptoms
and the average duration of colds. 
6) Honey. Honey was found (admittedly in one obscure German) study to
improve bronchitis and asthma.  Honey has also been found to have anti-tumor and
anti-inflammatory properties in other research and can give a nice boost in Nitric Oxide
for erectile strength.
7) The Two W's: Water and Warmth. Your mama was right: you need to keep
warm during winter as otherwise your body must divert needed resources towards
raising your body temperature instead of boosting your immune system. And mucus
in your nose is one of the major defense barriers and, if overly dry, leaves you
vulnerable to colds and flus.  That's an impressive reduction to say the
8) Exercise. A number of studies have shown that exercise improves
immunity, including increasing macrophage counts and the speed at which immune
cells cycle through the body, etc. Already one 2006 study of obese, sedentary women
directly found that
exercise (45 min/day of mostly brisk walking) significantly reduced their
incidence of colds.  And
four years later a study of a thousand adults found that those with the highest
fitness levels and/or did aerobic exercise more than five times per week were
almost half as likely to have an upper respiratory tract infection such as a
9) Humidity. One study found that 80% of influenza viruses survived in dry
conditions but only 10% moist.  In other words, a home humidifier may help
during the cold and flu season.
10) Vitamin D. Low Vitamin D levels have been linked in multiple studies to
increased frequency of colds and flus. Vitamin D is a miracle pill that boosts
immunity, fights cancer, decreases bone loss, increases heart health and on and
on. One study found that the lower range of Vitamin D individuals had a
30+% increased chance of an upper respiratory infection. 
Zinc. Regular readers of Peak Testosterone already know the importance
of Zinc in keeping Estrogen levels in check.
Zinc also has several immune-boosting powers. Zinc aids the body's production of lymphocytes, or
infection-fighting white blood cells, and Zinc has
been shown to inhibit the growth of visuses in the lab anyway. A lack of Zinc
has also been shown in several
studies to decrease immunity and prolongs recovery time.  (Studies are mixed
as to whether supplemental zinc helps with colds across the board however.) There are
many things that will deplete a guy's Zinc -
ejaculating and exercise being chief among them - and so it is easy for us male
studs to become depleted.
CAUTION: Please do not take more
than 1-2 times the RDA of Zinc and read
How Excess Zinc Can Be Dangerous. In
addition, watch out for Zicam or other zinc forumulations for your nasal
passages: they can lead to a permanent loss of smell.
Orgasm.. Would you believe that an orgasm can
increase signficantly the number of specialized killer cells that attack
Other studies have shown a nice rise in antibodies for those having regular sex. 
13) Hand Washing. Recent studies have shown that frequent
handwashing can reduce the incidence of respiratory colds and flus by about a
quarter and stomach illness by about a half.  It can also keep you from
eating crap, literally. One reporter swabbed door handles and other daily
surfaces and submitted them to a lab. Over half of the samples had fecal
contamination.  A more formal British study found that 28% of
commuters had fecal contamination on their hands.  A recent study also
showed that hand drying techniques are also critical. Hand drying by
rubbing ones hands together merely raised embedded germs to the surface. 
14) Cranberry Juice. One recent study showed that cranberry juice helps the body
protect itself from some of the nastiest bacteria, e. coli and s. aureus. 
Of course, these are some of the deadliest bacteria we have in everyday life
with e. coli being responsible for many deadly food poisonings and s. aureus to
blame for staff and MRSA infections. Previous studies have shown that said
juice makes life miserable for H. Pylori, the bacteria that often leads to
stomach ulcers and/or cancer.  How does cranberry juice work its magic
against these microbial heavy hitters? It prevents these two bacteria from
sticking to tissue walls and/or forming biofilms, which are mesh-like networks
that allow the spread and proliferation of the infection. Don't forget that
cranberry juice protects against urinary tract infections and raises HDL.
Yes, all in a day's work for one of nature's superfoods.
15) High Protein Diets. Higher protein diets have been linked to various immune
disorders and decreased immune function. For more details, see my link on
Protein and Immunity.
16) Probiotics. What is one of your biggest immune defenders? Your colon!
(Yes, health can be counterintuitive.) Intestinal flora provide your body with
one of its most important lines of defense and, more importantly, regulate a
variety of immune function pathways. One study after another has stacked up in
the last ten years showing that the right kind of probiotics can actually
prevent colds and other upper respiratory tract infections. Yes, it looks
like there is a cure for the common cold, or at least a big gun in one's
The pro-probiotics movement recently gained momentum when the Cochrane
Collaboration did a meta-analysis on all these studies and concluded that
certain probiotics showed a substantial reduction in the number of colds. 
Products with a good track record are "Lactobacillus casei DN-114 001
(DanActive), Lactobacillus reuteri ATCC 55730 (BioGaia Probiotic drops),
Lactobacillus rhamnosus GG (Culturelle), and LcS (Yakult)." 
CAUTION: Be very careful about
Overtraining, which can very quickly lead to
suppressed immunity. I document this phenomenon in my link on Overtraining
and Its Consequences.
1) Amer J of Clin Nutr, Oct 2007, 86(4):1167-1173
2) Clin Exp Immunol, 1978 May, 32(2): 370–379
3) Lancet, 2003, 361:1496-501
4) J Am Coll Nutr, 2003 Apr, 22(2):174-82
5) J Nutr, 2005, 135:2911S, Bukowski, "Is the Increased in [Delta Gamma} T Cell
Priming by Dietary Alkylamines Sufficient to prevent Cancer? What Other
Components of the Diet Prime [Delta Gamma] T Cells?"
6) CMAJ (Canadian Med Jour), October 25, 2005, 173(9), "Efficacy of an extract of
North American ginseng containing poly-furanosyl-pyranosyl-saccharides for
preventing upper respiratory tract infections: a randomized controlled trial"
7) Archives of Internal Medicine, 2009, 169:62-67
8) Therapie der Gegenwart, 1970 Feb, 109(2):260-8, "Treatment of chronic
bronchitis and bronchial asthma with honey"
9) Woman's Day, Riva Rahl, MD, Med. Dir. Copper Wellness Program, Dec 1 2009, p.
10) Amer J of Med, Nov 2006, 119(11)
12) Prevention, Jan 1009, p 16.
14) Neuroimmunomodulation, 2004, 11(5):293-298,"Effects of Sexual Arousal on
Lymphocyte Subset Circulation and Cytokine Production in Man"
15) BBC News, "Sex The Cold Cure", Wednesday, April 14, 1999
18) Shape, Nov 2009, p. 158.
19) Epidemiol Infect, 2010 Mar, 138(3):409-14. Epub 2009 Sep 2, "Dirty hands:
bacteria of faecal origin on commuters' hands"
20) Journal of Applied Microbiology, Article first published online: 7 SEP 2010,
"Comparative evaluation of the hygienic efficacy of an ultra-rapid hand dryer vs
conventional warm air hand dryers"
21) Presented at The 240th American Chemical Society National Meeting &
Exposition, August 25, 2010, “Oral consumption of cranberry juice inhibits
cellular adhesion and biofilm formation of uropathogenic bacteria” (Abstract
22) Critical Reviews in Food Science and Nutrition, 2002, 42(S3):279-284,
"Inhibition of Helicobacter pylori Adhesion to Human Gastric Mucus by a
High-Molecular-Weight Constituent of Cranberry Juice"
23) Cochrane Database of Systematic Reviews, 2011, Issue 9, "Probiotics for
preventing acute upper respiratory tract infections".
25) Br J Sports Med, 2010, "Upper respiratory tract infection is reduced in
physically fit and active adults"