Positive Health Online

Abstract

BECK, Department of Pediatrics, University of North Carolina at Chapel Hill, 27599-7220, USA, melinda_beck@unc.edu, reviewed (18 references) the effects of nutritional deficiency on immune system responses to infection and also discussed evidence for additional direct effects on viruses themselves.

Background

Malnutrition is associated with increased susceptibility to infection, thought to be a result of impaired immune function . However, the author and her fellow researchers have found that nutritional deficiency also affects the activity of infectious microorganisms invading malnourished individuals.

Methodology

The researchers looked at the specific case of selenium (Se) deficiency and found that mice deficient in Se were more susceptible to both coxackievirus and influenza virus . Those mice infected with a normally harmless strain of coxackievirus developed myocarditis . Similarly, Se-deficient mice infected with a mild strain of influenza virus developed severe pneumonitis . Glutathione peroxidase knockout mice also developed myocarditis after being infected with a normally harmless viral strain, indicating that the antioxidant selenoenzyme glutathione peroxidase-1 was critical in the normal (successful) battle against viral infection. The researchers sequenced viral samples isolated from Se-deficient mice and found mutations in the viral genomes of both coxackievirus and influenza virus that indicated increased virulence of the microorganisms.

Results

Conclusion

The nutritional status of an individual is important not only for ensuring an optimal response of the immune system to an invading virus, but also in preventing viral mutations that can lead to increased pathogenicity of the virus itself.

References

Beck MA. Antioxidants and viral infections: host immune response and viral pathogenicity. Journal of the American College of Nutrition 20 (5 Suppl): 384S-8S; discussion: 396S-7S. Oct 2001.