Why Is Flu Risk So Much Higher In The Winter?

Following text is an excerpt from a report in the February 2007 issue of LE Magazine:

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REPORT

Unraveling a Centuries-Old Mystery
Why Is Flu Risk So Much Higher in the Winter?

By Dale Kiefer, LE Magazine February 2007

This age-old mystery has confounded scientists for the last century. Like clockwork, influenza infects the majority of its victims during the winter months in both the Northern and Southern hemispheres. Infection with the flu virus leaves millions around the world bedridden with debilitating symptoms such as fever, body pains, sore throat, and cough. The very young and elderly are particularly susceptible to catastrophic complications from the flu, including death. Moreover, the recent emergence of flu strains such as H5N1 leaves many experts on infectious disease worried about the potential for global devastation even worse than that of the 1918-19 flu pandemic, which was linked to at least 50 million deaths worldwide.

A fascinating new theory seeks to explain why flu takes hold during the winter months and why it infects so many people, particularly elderly adults. At the heart of this theory is the presence of a vitamin deficiency in certain populations, including aging adults, around the world.

Influenza Outbreak: A Modern Mystery

One of the greatest medical mysteries of the ages may finally have been solved, thanks to a newly published theory regarding the relationship between influenza and its peak onset during the winter months.1 Published just months before the start of the annual flu season, this novel theory addresses questions that have puzzled scientists for decades: why does flu strike almost exclusively in winter, and why are the elderly often at greatest risk of contracting the disease?

The answers to these questions are of more than academic interest. In the US alone, influenza hospitalizes more than 100,000 people—and kills more than 30,000—in an average year.2,3 With the recent scares over avian (bird) flu and severe acute respiratory syndrome (SARS), many scientists believe it is only a matter of time before the world is gripped by a deadly pandemic. Improving our understanding of these diseases may help us avert disaster from influenza and other severe respiratory viruses.

Surprisingly, the solution may be as simple as supplementing with higher-than-usual amounts of a common vitamin in the fall and winter months.2,4 The story behind this proactive approach to flu prevention begins in England more than a quarter century ago, eventually coming to fruition in California.

Popular Misconceptions About the Flu

First, some background on the influenza virus is in order. Epidemiological data from around the globe indicate that while flu cases are not entirely unheard of in summer, outbreaks of this virus peak soon after the winter solstice in temperate latitudes.5 For years, health experts have speculated that the explanation for this seasonality is that people tend to congregate indoors more often in winter, thus fostering rapid person-to-person transmission. However, in this age of ubiquitous air conditioning and 9-to-5 jobs, is there really much difference in the potential for interpersonal contact from one season to another? While children probably spend more time indoors in winter due to school schedules, what about adults?

In fact, the “huddling inside” explanation has never been found to account for the seasonal nature of influenza infection. In a recent article on influenza transmission, a respected researcher at the federal Centers for Disease Control and Prevention noted that no human experimental studies have delineated the person-to-person transmission of influenza. Instead, the virus appears to be spread through indirect contact, with transmission through respiratory droplets the most probable explanation at this time.5 However, since these minute respiratory particles are unavoidable, this theory fails to explain why influenza occurs more often in winter and why certain individuals demonstrate protection against the flu. This puzzle has led researchers to continue searching for factors contributing to the infectious nature of influenza viruses.

Unraveling the Influenza-Winter Season Connection

Dr. John Cannell, a California psychiatrist, is the chief author of a landmark theory that postulates that influenza epidemics are intimately linked to declining vitamin D levels.1

In California, Dr. Cannell works with patients at a maximum-security hospital for the criminally insane. In recent years, he had become aware that vitamin D is a unique compound with profound effects on human immunity. He had kept abreast of cutting-edge research demonstrating that vitamin D has numerous wide-ranging effects in the body, influencing everything from bone health and cancer prevention to blood pressure.1,6,7 Dr. Cannell also knew that an alarming number of otherwise healthy people are deficient in this crucial vitamin, especially in winter. “I realized that vitamin D is really quite different from other vitamins,” he recently told Life Extension.

Most of Dr. Cannell’s patients are African-Americans whose skin pigmentation interferes with the sunlight-driven production of natural vitamin D. This fact, combined with their confinement, led Dr. Cannell to suspect that his patients’ blood levels of vitamin D would be abnormally low. Testing confirmed this to be the case. After educating his patients about vitamin D’s potential benefits, Dr. Cannell prescribed routine supplementation with 2000 IU of vitamin D3 (cholecalciferol) daily. He says he would have given the men even higher doses, but 2000 IU represents the current “upper limit” of vitamin D intake recommended by the government-sponsored Food and Nutrition Board of the Institute of Medicine. By contrast, most adult multivitamins deliver just 400 IU of vitamin D, and a single eight-ounce glass of fortified milk delivers just 100 IU.7

Patients Stay Flu-Free Amidst an Epidemic

In the late winter of 2005, influenza broke out at the hospital. Ward after ward was quarantined, as patients were gripped with the chills, fever, cough, and severe body aches characteristic of the influenza A strain of the virus. “First, the ward below mine was infected,” says Dr. Cannell, “and then the wards on my right, left, and across the hall.” To his growing amazement, however, his own patients remained unaffected. “My patients had intermingled with patients from infected wards before the quarantines,” he notes. “I felt certain that my patients had been exposed to the influenza virus.” His patients’ enduring health in the midst of a local epidemic profoundly influenced Dr. Cannell’s thoughts on the relationship between vitamin D and immunity to the flu.7

He recalled the work of a pioneering British physician, Dr. R. Edward Hope-Simpson. Working in virtual obscurity, Hope-Simpson was catapulted to fame in the mid-1960s when he discovered the cause of shingles, a painful condition that affects adults. Thanks to Hope-Simpson, we now know that shingles results from the reactivation of latent chicken pox virus. After announcing this widely hailed discovery, Hope-Simpson turned his attention to influenza and was the first to document that in temperate latitudes, influenza A epidemics invariably peak in the month following the winter solstice. This pattern holds true for both the Northern and Southern hemispheres, and cases tend to rise and fall for about two months before and after the peak.8

Noting the obvious relationship between the decline in sunshine and rise of influenza, Hope-Simpson proposed that an undetermined “seasonal stimulus” must be responsible. Although he recognized that solar radiation had to be involved in evoking this seasonal stimulus, he was at a loss as to what the actual stimulus might be. Before his death in 2003, Hope-Simpson published numerous papers documenting the seasonal nature of influenza. While flu cases occasionally occur in summer, they rarely cause communal outbreaks. It may seem like common sense to acknowledge that flu is a winter phenomenon, but the fact had never been scientifically documented before. Hope-Simpson also noted, and other scientists have now confirmed, that flu outbreaks in the tropics tend to occur in the rainy season, when sunshine is scarce.4,7,9

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References

1. Cannell JJ, Vieth R, Umhau JC, et al. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.

2. Reid AH, Taubenberger JK. The origin of the 1918 pandemic influenza virus: a continuing enigma. J Gen Virol. 2003 Sep;84(Pt 9):2285-92.

3. Thompson WW, Shay DK, Weintraub E, et al. Mortality associated with influenza and respiratory syncytial virus in the United States. JAMA. 2003 Jan 8;289(2):179-86.

4. Rapuri PB, Kinyamu HK, Gallagher JC, Haynatzka V. Seasonal changes in calciotropic hormones, bone markers, and bone mineral density in elderly women. J Clin Endocrinol Metab. 2002 May;87(5):2024-32.

5. Bridges CB, Kuehnert MJ, Hall CB. Transmission of influenza: implications for control in health care settings. Clin Infect Dis. 2003 Oct 15;37(8):1094-101.

6. Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr. 2004 Dec;80(6 Suppl):1678S-88S.

7. Available at: http://www.medicalne...hp?newsid=51913. Accessed November 3, 2006.

8. Hope-Simpson RE. The role of season in the epidemiology of influenza. J Hyg (Lond). 1981 Feb;86(1):35-47.

9. Shek LP, Lee BW. Epidemiology and seasonality of respiratory tract virus infections in the tropics. Paediatr Respir Rev. 2003 Jun;4(2):105-11.

10. Kobasa D, Takada A, Shinya K, et al. Enhanced virulence of influenza A viruses with the haemagglutinin of the 1918 pandemic virus. Nature. 2004 Oct 7;431(7009):703-7.

11. Chan MC, Cheung CY, Chui WH, et al. Proinflammatory cytokine responses induced by influenza A (H5N1) viruses in primary human alveolar and bronchial epithelial cells. Respir Res. 2005;6135.

12. Beigel JH, Farrar J, Han AM, et al. Avian influenza A (H5N1) infection in humans. N Engl J Med. 2005 Sep 29;353(13):1374-85.

[...]

32. Gloth FM 3d, Gundberg CM, Hollis BW, Haddad JG Jr, Tobin JD. Vitamin D deficiency in homebound elderly persons. JAMA. 1995;274:1683-6.

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The preceeding text is an excerpt from:

REPORT

Unraveling a Centuries-Old Mystery
Why Is Flu Risk So Much Higher in the Winter?

By Dale Kiefer, LE Magazine February 2007

( http://www.lef.org/L...px?CmsID=114613 )

Thanks for your reply, Phil.

Phil Conners, on 2007-04-28 23:51:42, said:

According to http://en.wikipedia.org/wiki/Vitamin_D "Vitamin D3 is produced in skin exposed to sunlight, specifically ultraviolet B radiation." so unlikely to be a problem in Thailand

In the last sentence in my article excerpt (just before the references) it says:

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Hope-Simpson also noted, and other scientists have now confirmed, that flu outbreaks in the tropics tend to occur in the rainy season, when sunshine is scarce.4,7,9

References
1. Cannell JJ, Vieth R, Umhau JC, et al. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.
9. Shek LP, Lee BW. Epidemiology and seasonality of respiratory tract virus infections in the tropics. Paediatr Respir Rev. 2003 Jun;4(2):105-11.

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(Phil, note that tropics is above mentioned 2 times.)

Many people, perhaps you included, who live in the sunny climate of Thailand get more than enough vitamin-D producing sunshine on their skin daily. However, there are many, both natives and foreigners who don't get long and regular exposure to sunshine. I for one certainly have to take cod liver oil for its vitamin-D specifically to prevent from loosing my teeth! And many Thais are for some strange reason so enamored with the "White is right" mindset that they avoid the sun at all costs. I would image that there must be many hundreds of thousands of Thai Pooyings that do this religiously.

At this point, I would like to make a suposition (guess) that concerning medical/health therapeutics that YOU subscribe to the paradigm (method) of single agents to get the job done. In this case, 'getting the job done' means fighting off or preventing a viral infection. (By single agent I refer to as in "I hope this course of Tamiflu or whatever medicine is going to get the job done.")

And might I also guess that YOU due to that paradigm subscribe to a single cause for most diseases and this viral infection disease in particular.

I guess all I want to say is just to point out that it appears to me that (in this late day and age of early 21st century) the paradigm of multiple causes and multiple therapeutic agents is the most reliable paradigm (method) to get the job done.

Antibiotic resistant germs and ineffectual antibiotics and antiviral drugs. What's needed today is multiple strategic doses of a 'spectrum' of natural immune enhancing nutrients, vitamins, minerals and herbs.

So Phil, exactly what might I be talking about?... See the 10 agents in that other article I found. And now add FOR ME (not for you) number 11, being vitamin-D. ... ... Yep, that sounds like a delicious Coctail-11 for me!

[See the 10 immune enhancing agents in the article refered to in my previous post, above. "The Reality about Vaccines" and "Why Antibiotics and Antivirals Fail".