Tuesday, January 08, 2013

Flu Shot Realities

Nutrition and Seasonal Flu

Antibiotics fight bacteria but won’t help against viral infections, and there are limited medical options. Flu drugs must be taken within 48 hours of the first symptoms of influenza and only claim to reduce symptoms by about 1.5 days. [1], [2]

Flu shots are only effective against 1-3 strains of influenza; depending on how lucky the researchers’ guess was several months earlier. But exposure to one or more flu strains, such as by getting a flu shot, actually make us more susceptible to infection from other virus strains by reducing our immune response.  Researchers know that, theoretically, when people are exposed to bacteria or a virus, it can stimulate the immune system to create antibodies that facilitate the entry of another strain of the virus or disease. For example, Canadian researchers in four separate studies found that people who had received the seasonal flu vaccine in the past were more likely to get sick with the H1N1 virus. [3]

There is evidence that the nutrient status of the host even affects the genetic expression of viruses. An unsuitable environment like a well-nourished body inhibits the ability of a virus to freely replicate and thrive. This not only makes viruses more virulent, but also more prone to mutate inside us to become more immune- and drug-resistant strains if we are nutrient deficient! [4], [5], [6], [7]

Research going back over a century has proven that nutrient deficiencies, for example of vitamins A or D, can lead to increased susceptibility to infectious diseases. A well-known and decades-old example is the strong association of vitamin A deficiency with the development of more severe measles infections, leading to a much higher rate of mortality. 5

Although the immune response has been demonstrated to be impaired in nutritionally deficient hosts, the actions and vigor of the virus itself may also be affected by the nutritional deficiency. Viruses have been shown to develop increased virulence due to changes in their genomes when replicating in a nutritionally deficient host. The exact mechanism for viral genetic changes is not well documented but seems related to increased oxidative stress in the host. For example, selenium-deficient mice were more susceptible to viral infections, and developed severe forms of illnesses even when infected with mild viral strains. Both the immune system and the viral systems were affected by the nutrient deficiency in ways that strengthened the virus and weakened the host. 5

Volunteers inoculated with live attenuated influenza virus are more likely to develop fever and evidence of an immune response in the winter when vitamin D levels are naturally low.  And an interventional study showed that vitamin D reduced the incidence of respiratory infections in children. [8]

Compelling epidemiological evidence indicates that vitamin D deficiency is a stimulus causing seasonal flu rates to be much higher in the winter months than the summer months. Evidence now confirms that lower respiratory tract infections are more frequent, sometimes dramatically so, in those with low serum vitamin D levels. In an intervention study, 800 IU of vitamin D daily reduced seasonal flu levels in winter months to the low levels commonly reported in summer months...virtually eliminating seasonal flu in that population. [9]

We can see that vaccines and flu drugs convey only limited protection and treatment against viral infections, and that the wisest course is to fortify our immunity with adequate nutrient intake.

[1] http://www.tamiflu.com/treat.aspx 
[2] http://www.relenza.com/
[3] CBC News 9/23/09; Dr. Michael Gardam, director of infectious diseases prevention and control at the Ontario Agency for Health Protection and Promotion
[4] Cunningham-Rundles S, McNeeley DF, Moon A.  Mechanisms of nutrient modulation of the immune response.  J Allergy Clin Immunol. 2005 Jun;115(6):1119-28; quiz 1129. Review.
[5] Zaslaver M, Offer S, Kerem Z, Stark AH, Weller JI, Eliraz A, Madar Z. Natural compounds derived from foods modulate nitric oxide production and oxidative status in epithelial lung cells.  J Agric Food Chem. 2005 Dec 28;53(26):9934-9.
[6] Calder PC, Kew S.  The immune system: a target for functional foods? Br J Nutr. 2002 Nov;88 Suppl 2:S165-77.
Janeway, Charles A.; Travers, Paul; Walport, Mark; Shlomchik, Mark (2001) Immunobiology, 5th Ed., Garland Publishing, New York and London.
[7] Beck MA, Handy J, Levander OA. Host nutritional status: the neglected virulence factor. Trends Microbiol. 2004 Sep;12(9):417-23. Review. PMID: 15337163
[8] Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, Garland CF, Giovannucci E. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40. Epub 2006 Sep 7. Review. PMID: 16959053
[9] Cannell JJ, Zasloff M, Garland CF, Scragg R, Giovannucci E. On the epidemiology of influenza. Virol J. 2008 Feb 25;5:29. Review. PMID: 18298852

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