The flu can mean more than symptoms such as muscle pain, nausea, and sore throat.3 On average, over 30,000 Americans die annually from influenza.1
To help prevent death from the flu’s lethal secondary infections and other complications, many people choose to receive an annual flu shot.13 However, because older adults often have a weakened immune system, the vaccine may only be effective as infrequently as 9% of the time—and only 56% of the time in the general population.16-18
However, when taken together for two weeks prior to vaccination, the amino acids L-theanine and L-cystine boost the efficacy of the flu vaccine in certain elderly subjects by enhancing the immune system itself.19 The result is enhanced protection against both the flu virus—and its deadly complications.
Remarkably, this same combination has been shown to reduce the incidence of the common cold by 58%.5
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- Available at: http://www.cdc.gov/nchs/data/nvsr/nvsr61/nvsr61_06.pdf. Accessed September 21, 2013.
- Available at: http://www.flu.gov/symptoms-treatment/symptoms/index.html#. Accessed September 21, 2013.
- Takagi Y, Kurihara S, Higashi N, et al. Combined administration of (L)-cystine and (L)-theanine enhances immune functions and protects against influenza virus infection in aged mice. J Vet Med Sci. 2010 Feb;72(2):157-65.
- Kurihara S, Hiraoka T, Akutsu M, Sukegawa E, Bannai M, Shibahara S. Effects of (L)-cystine and (L)-theanine supplementation on the common cold: a randomized, double-blind, and placebo-controlled trial. J Amino Acids. 2010;2010:307475.
- Available at: http://www.cdc.gov/flu/about/disease/symptoms.htm. Accessed September 30, 2013.
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- Centers for Disease Control and Prevention (CDC). Estimates of deaths associated with seasonal influenza—United States, 1976-2007. MMWR Morb Mortal Wkly Rep. 2010 Aug 27;59(33):1057-62.
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- Available at: http://www.cdc.gov/flu/about/disease/high_risk.htm. Accessed September 23, 2013.
- Available at: http://www.cbsnews.com/8301-504763_162-57521511-10391704/officials-urge-flu-vaccine-for-unpredictable-2012-2013-season/. Accessed September 23, 2013.
- Available at: http://www.vhcinfo.org/serviceMembers.asp?page=immunoBasics&title=Immunology%20Basics. Accessed September 23, 2013.
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- Miyagawa K, Hayashi Y, Kurihara S, Maeda A. Co-administration of l-cystine and l-theanine enhances efficacy of influenza vaccination in elderly persons: nutritional status-dependent immunogenicity. Geriatr Gerontol Int. 2008 Dec;8(4):243-50.
- Kurihara S, Shibahara S, Arisaka H, Akiyama Y. Enhancement of antigen-specific immunoglobulin G production in mice by co-administration of l-cystine and l-theanine. J Vet Med Sci. 2007 Dec;69(12):1263-70.
- Available at: http://www.nhs.uk/Conditions/Cold-common/Pages/Commoncoldinchildren.aspx. Accessed September 24, 2013.
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- Ison MG, Campbell V, Rembold C, et al. Cardiac findings during uncomplicated acute influenza in ambulatory adults. Clin Infect Dis. 2005;40:415-22.
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- McElhaney JE, Beattie BL, Devine R et al. Age-related decline in interleukin 2 production in response to influenza vaccine. J Am Geriatr Soc. 1990;38:652-8.
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