Nutritional Status & Viral Infections

I wanted to write a quick blog on an incredibly important concept when it comes to viral infections, and that is that:

The nutritional status of the host can have a profound influence on a virus, so that a normally avirulent virus becomes virulent because of changes in the viral genome.

We have known for a long time that the nutritional status of the host influences both susceptibility to infectious disease and the severity of the disease if contracted. In fact, the inspiration for this blog comes from a paper published in 2000 in The American Journal of Clinical Nutrition.

Many investigations have shown that diets lacking one or more nutrients can exacerbate the consequences of either bacterial or viral infections. This increased susceptibility is widely attributed to changes in the immune status of the host. Thus, the current paradigm holds that a nutritional deficiency will decrease the immune response of the host, leading in turn to increased susceptibility to infection.

However is there another element to this increased susceptibility?

One must consider, however, that the pathogen is replicating in a nutritionally deficient environment (the host), which might also be expected to influence the pathogen. The work of the authors of this paper has focused on both changes in the host and changes in the pathogen, and they have found that the nutritional status of the host can have a profound influence on a virus, such that a normally avirulent virus acquires virulence as a result of changes in the viral genome.

In a fascinating experiment researchers found that selenium-adequate mice infected with virus from selenium-deficient mice developed myocarditis. The authors concluded that this suggests that a change in viral genotype was responsible. Selenium-adequate mice infected with virus obtained from selenium-adequate mice did not develop myocarditis, demonstrating that passage of virus alone did not induce the change.

Our studies suggest that outbreaks of disease attributed to a nutritional deficiency may actually result from infection by a virus that has become pathogenic by replicating in a nutritionally deficient host.

A paper entitled ‘Potential interventions for novel coronavirus in China: A systematic review’ states:

the nutritional status of each infected patient should be evaluated before the adminis- tration of general treatments

So in some summary having nutritional deficiencies may:

  • Increase our risk of contracting an infection.
  • Make it worse.
  • Allow a virus lying dormant within us to become re-activated.

Considering our nutrient status is essential and numerous things influence our status. I’ll be back soon with a blog on what might influence our nutrient status. Stay tuned.

References:

Beck, Nutritionally induced oxidative stress: effect on viral disease, Am J Clin Nutr 2000;71(suppl):1676S–9S

Zhang & Liu, Potential interventions for novel coronavirus in China: A systematic review, J Med Virol. 2020;92:479–490

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