Influenza and Immunity

Here at Natural Grocers by Vitamin Cottage we are aware that many of our customers have concerns about the upcoming cold and flu season. This summer we have not seen the typical lull in outbreaks of infection; this has increased the concern that during this coming winter season, the rates of infection may be higher than average. We thought we would turn to naturopathic doctor, Jacob Schor to get his best recommendations to prepare your immune system for this year's cold and flu season.

Dr. Schor advises that the supplements listed below (elderberry is the exception) are to be taken long term throughout the cold and flu season to support immunity -- not as short-term treatments. This doesn't mean that you won't get sick, but a healthy immune system is better able to handle an infection, lessening symptoms, duration, and severity.

Vitamin D

Flu is a seasonal illness; outbreaks increase in the late winter and decrease in the summer. In 1981 British epidemiologist Edgar Hope-Simpson identified summer light as protective against flu infection. A quarter century later, John Cannell advanced this theory and realized that summer sunlight increases vitamin D levels. In late winter as people become deficient, infections increase.ⁱ We now know that vitamin D is necessary to make cathelicidin, an infection-fighting immune compound. I encourage my patients to take vitamin D now in preparation for flu season. I suggest testing and striving for a 25(OH) D-3 level above 50 ng/ml by taking 3,000 to 5,000 IU/day.

Vitamin D was once thought to be toxic. Current research says this is not true. Even doses as high as 10,000 IU per day are considered safe. ⁱⁱ

N-acetyl cysteine (NAC)

N-acetyl cysteine increases the body's supply of glutathione, a powerful antioxidant that protects cells and supports the body’s normal detoxification processes. NAC is also often used to break up mucous in the lungs.

In a double blind, placebo-controlled trial 262 participants, 65 years or older, took 1,200 mg of NAC daily for six months, during the winter. Few of the subjects taking NAC developed flu symptoms, even though blood tests confirmed they were infected. When subjects did develop symptoms, they were generally mild among people taking NAC, compared with those who were taking placebos. NAC controlled the respiratory symptoms of the flu and, through its conversion to glutathione, boosted the body’s ability to manage infection. ⁱⁱⁱ

Probiotics

Several studies tell us that probiotics also decrease flu and cold symptom intensity.^{iv v} One recent study published in the journal Pediatrics described a placebo controlled trial in which 326 children took a combination of two probiotics or a placebo daily. The probiotics reduced fever incidence by 53 percent, coughing incidence by 62 percent, and runny noses by almost 60 percent. ^vi

Colostrum

A 2007 study compared the benefit of the flu vaccine with taking one capsule of colostrum daily to see which best prevented illness. The study had two parts. The first part looked at healthy adults and the second looked at patients with advanced cardiovascular disease. For healthy patients, colostrum was four times more effective than the flu vaccine. Colostrum was three times more effective than no treatment. The group of patients who received both vaccine and colostrum group did equally well as colostrum alone. In patients with heart disease, colostrum was twice as effective as the flu vaccine. ^vii

Elderberry

Elderberry (Sambucus nigra) also has a long history of use for flu. About ten or fifteen years back, a proprietary extract was developed by a virologist in Israel and it became popular after studies showed that it shortened the duration and intensity of flu infections.^viii A paper published this past August reported that elderberry extracts have a direct antiviral activity against the flu virus, an effect comparable to the antiviral prescription drugs. ^{ix x}

Be prepared

We don't know what the flu will do this winter. But we can be proactive and do what we can to lower risk of infection and seriousness of symptoms.

For more information, visit these websites:
National Institute of Health Flu site: www.Flu.Gov
Center for Disease Control's weekly flu report: http://www.cdc.gov/flu/weekly/
Paul Herscu, ND: http://www.hersculaboratoryflu.org/
Paul Bergner on Flu: http://naimh.com/Influenza-1918.pdf
John Cannel: http://www.vitamindcouncil.org/

References:

ⁱ Cannell JJ, Vieth R, Umhau JC, Holick MF, Grant WB, Madronich S, et al. Epidemic influenza and vitamin D. Epidemiol Infect. 2006 Dec;134(6):1129-40.

ⁱⁱ Vieth R. Vitamin D toxicity, policy, and science.J Bone Miner Res. 2007 Dec;22 Suppl 2:V64-8.

ⁱⁱⁱ De Flora, S. et al. Attenuation of influenza-like symptomatology and improvement of cell- mediated immunity with long-term N-acetylcysteine treatment. Eur Respir J 1997 10 (7) 1535-41

^iv Pregliasco F, Anselmi G, Fonte L, Giussani F, Schieppati S, Soletti L. A new chance of preventing winter diseases by the administration of synbiotic formulations. J Clin Gastroenterol. 2008 Sep;42 Suppl 3 Pt 2:S224

^v de Vrese M, Winkler P, Rautenberg P, Harder T, Noah C, Laue C, et al. Probiotic bacteria reduced duration and severity but not the incidence of common cold episodes in a double blind, randomized, controlled trial. Vaccine. 2006 Nov 10;24(44-46):6670-4.

^vi Leyer GJ, Li S, Mubasher ME, Reifer C, Ouwehand AC. Probiotic effects on cold and influenza-like symptom incidence and duration in children. Pediatrics. 2009 Aug;124(2):e172-9. Epub 2009 Jul 27.

^vii Prevention of influenza episodes with colostrum compared with vaccination in healthy and high-risk cardiovascular subjects: the epidemiologic study in San Valentino. Cesarone MR, Belcaro G, Di Renzo A, Dugall M, Cacchio M, Ruffini I, Pellegrini L, Del Boccio G, Fano F, Ledda A, Bottari A, Ricci A, Stuard S, Vinciguerra G. Clin Appl Thromb Hemost. 2007 Apr;13(2):130-6.

^viii Zakay-Rones Z, Varsano N, Zlotnik M, Manor O, Regev L, Schlesinger M, Mumcuoglu M. Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B Panama. J Altern Complement Med. 1995 Winter;1(4):361-9.

^ix Roschek B Jr, Fink RC, McMichael MD, Li D, Alberte RS. Elderberry flavonoids bind to and prevent H1N1 infection in vitro. Phytochemistry. 2009 Aug 12.

^x Zakay-Rones Z, Thom E, Wollan T, Wadstein J. Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infections. J Int Med Res. 2004 Mar-Apr;32(2):132-40.