Preparing for the Next Appearance of Spanish Flu

The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 6 No. 2 • April–May 2003

Preparing for the Next Appearance of Spanish Flu

The Spanish flu epidemic of 1918 killed 20–30,000,000 people (probably a low estimate). The mortality rate was about 2.5%. Of course, nobody really knows whether it was actually a form of influenza or some other virus. Although samples of tissue from Spanish flu victims that were stored have been examined, and cadavers buried in permafrost have even been dug up, nobody has been able to isolate any influenza sequences by PCR. Many viruses have symptoms that can be described as flulike.

A recent paper1 reports, however, that influenza infections are characterized by decreased levels of intracellular glutathione and that people with low levels of this antioxidant are more susceptible to infection. In fact, many viruses cause oxidative stress, with decreases in intracellular glutathione, including, for example, Sendai virus, HIV virus, and herpes simplex virus type 1.

In this study, researchers found that glutathione significantly inhibited production of active influenza virus, both in cell cultures (MDCK cells) and in a normal human small-airway-epithelial cell line. They also added supplemental glutathione (50 mM) to the drinking water of female Balb/c mice inoculated with influenza and found that it inhibited viral titer in trachea and lung.

The dose of influenza used to treat the mice was not lethal; none of the mice died during the experiment. The glutathione was found not to exert its effects on active virus production by preservation of the total lung glutathione content. The authors suggest that the glutathione probably had an effect in the oral, nasal, or upper-airway epithelium.

The limiting factor in the body’s manufacture of glutathione is the amino acid cysteine. In fact, a clinical trial with 262 subjects who were given a continuous supplement of N-acetylcysteine (600 mg twice daily) for six months showed significant protection against flulike symptoms, although (the authors note) N-acetylcysteine may not protect the rate of infection per se.1 The way that N-acetylcysteine is used by the body to make glutathione requires that it be deacetylated to cysteine. We take cysteine supplements ourselves as part of our daily personal regimen. See our discussion in this newsletter (Vol. 5 No. 5, Oct. 2002) on why we use cysteine rather than N-acetylcysteine.

The researchers suggest that glutathione “provides an alternate [to antiviral drugs] strategy to limiting influenza infection.”

Vitamin C helps prevent cysteine from being oxidized to insoluble cystine in your kidneys and urinary bladder.


  1. Cai et al. Inhibition of influenza infection by glutathione. Free Rad Biol Med 34(7):928-36 (2003).

Featured Product

  • Learn more about Vitamin C benefits and implementation strategies.

FREE Subscription

  • You're just getting started! We have published thousands of scientific health articles. Stay updated and maintain your health.

    It's free to your e-mail inbox and you can unsubscribe at any time.
    Loading Indicator