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Beta Glucan is a natural, branched polysaccharide (a
molecule made up of many sugar units). It is composed of glucose
molecules extracted and purified from the cell wall of common baker’s
yeast. Beta Glucan enhances immunity by binding to macrophages and
other phagocytic white blood cells at certain receptors and
activating their anti-infection and anti-tumor activity by
stimulating the production of free radicals. This stimulation
signals the phagocytic immune cells to engulf and destroy foreign
bodies, be they bacteria, viruses or tumor cells.
In
a 2004 study, researchers tested the effects of oat beta
glucan on respiratory infection, macrophage antiviral resistance, and
NK cytotoxicity in mice. Results indicated that ingestion of beta
glucan before infection prevented an increase in morbidity and
mortality. Exercise stress was associated with a decrease in
macrophage antiviral resistance, which was blocked by ingestion of
beta glucan. (Effects of oat beta-glucan on innate immunity and
infection after exercise stress. Med Sci Sports Exerc. 2004
Aug;36(8):1321-7).
In
a 2003 study, the effect of beta-glucan on the enhancement of
resistance to infections caused by Staphylococcus aureus and Eimeria
vermiformis was studied in mice. An in vitro study using macrophages
isolated from the peritoneal cavity showed that beta-glucan treatment
significantly enhanced phagocytic activity. An in vivo study further
demonstrated that beta-glucan treatment induced a significant
protection against the challenge with S. aureus in mice.
(Beta-glucan,
extracted from oat, enhances disease resistance against bacterial and
parasitic infections. FEMS Immunol Med Microbiol. 2003 Jan
21;35(1):67-75.) Echinacea
is a plant native to the United States. The word
Echinacea actually comes from a Greek word 'echinos,' which means sea
urchin and refers to the plant's sea-urchin-shaped, flowering head.
It was recognized over a century ago as a natural infection fighter.
Echinacea is an immunostimulant in that it enhances the immune
system. Evidence shows that it stimulates the body to produce
more infection-fighting white blood cells, such as T-lymphocytes and
killer white blood cells. It may also stimulate the release of
interferons, one of the body's most potent infection-fighting
weapons. Interferon kills germs and also infiltrates their genetic
control center, preventing them from reproducing. Besides helping the
body produce more infection- fighting cells, echinacea helps these
cells to produce more germ-eating cells, called macrophages, and it
helps these cells eat the germs more voraciously, a process called
phagocytosis. Echinacea also prevents bacteria from secreting an
enzyme called hyaluronidase, which enables them to break through
protective membranes, such as the lining of the intestines and
respiratory tract, and invade tissues. Echinacea also seems to search
out and destroy some viruses, such as the common cold and flu
viruses.
Many clinical
studies demonstrate Echinacea’s efficacy as an immune system
stimulant. According to the authors of a 1999
meta-analysis Echinacea is effective against respiratory infections,
especially if taken as soon as the first symptoms appear.
(Barrett
B, Vohmann M et Calabrese C. Echinacea for Upper respiratory
infection. J Fam Pract 1999;48(8):628-35).
A double-blind
placebo-controlled study was conducted in Sweden in 1999. 246
patients suffering from colds took either 6 Echinacea tablets daily,
or a placebo. Echinacea was significantly more effective than the the
placebo.]
(Brinkeborn
RM, Shah DV, Degenring FH. Echinaforce®
and other Echinacea fresh plant preparations in the treatment of the
common cold. A randomized, placebo controlled, double-blind clinical
trial. Phytomedicine 1999 Mar;6(1):1-6).
A
2002 study involving 48 volunteers showed that Echinacea
significantly increases one of the markers of immune system
stimulation: properdine.
Kim
LS, Waters RF, Burkholder PM. Immunological activity of larch
arabinogalactan and Echinacea: A preliminary, randomized,
double-blind, placebo-controlled trial. Altern Med Rev
2002 Apr;7(2):138-149). Zinc
is an essential mineral that is necessary for the functioning of over
300 different enzymes. As well as it’s involvement in carbohydrate,
protein, fat and energy metabolism, it has been shown to support the
immune system. -lymphocytes are white blood cells that help fight
infection and depend on zinc for their development and activation. In
humans, zinc deficiency can result in a decreased number of
T-lymphocytes and a diminished ability to fight infection and heal
wounds. Because supplemental zinc may help fight infection and heal
wounds, zinc status is especially important for patients with
conditions such as HIV infection.
(Fraker
PJ, King LE, Laakko T, Vollmer TL. The dynamic link between the
integrity of the immune system and zinc status. J Nutr. 2000
May;130(5S Suppl):1399S-406S).
(Lim
Y, Levy M, Bray TM. Dietary zinc alters early inflammatory responses
during cutaneous wound healing in weanling CD-1 mice. J Nutr. 2004
Apr;134(4):811-6). Iron
is present in every cell. It is a component of hemoglobin in red
blood cells, binding the oxygen that the blood circulates throughout
the body. We need iron for strength and vigor, and the element plays
a key role in DNA and enzyme synthesis and other basic life
processes. Numerous studies indicate that a lack of iron lowers
immunity. Adequate levels help maintain cellular immunity and help
to protect against some infections. Cell-mediated immune response may
be impaired when iron deficiency negatively impacts the
iron-requiring enzyme called ribonculeotide reductase, an enzyme that
appears to be essential for the proper function of the T-lymphocyte
arm of immunity. Resistance to candida, herpes simplex virus and some
other pathogens appears to be reduced in those with poor iron status.
On the other hand, excess iron may predispose individuals to some
infections.
(Immune
function is impaired in iron-deficient, homebound, older women.
N. Ahluwalia, J. Sun, D. Krause, et al., Am J
Clin Nutr, 2004, vol. 79, pp. 516—521).
(Dallman
PR. Iron deficiency and the immune response. Am J Clin Nutr.
1987; 46:329-334).
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