
Good
Nutrition Could Help Prevent Bad VirusesBy Judy McBride June 8, 2001Once again, a relatively benign virus
has mutated into a nasty pathogen in laboratory mice that were raised on a diet
deficient in selenium, a potent antioxidant. This time the mutations occurred
in a common influenza virus, a strain isolated in Bangkok in 1979. And the mutations persisted in mice fed ample selenium, causing a much more
severe case of flu than the original strain. A report on the study, by
researchers with the University of North
Carolina, the
Nestle
Research Center in Switzerland and the Agricultural Research Service, will appear
online in The FASEB Journal
Express. The discovery, according to the researchers, demonstrates a unique mechanism
by which viruses can mutate and points to the importance of antioxidant
protection against viral diseases. The selenium level in the studys
deficient diet was one-sixtieth that of the adequate diet. Seven years ago, UNC virologist Melinda A. Beck and ARS nutritionist Orville
Levander reported that a lesser known virus--a strain of coxsackie--mutated
from Jekyll to Hyde in selenium-deficient mice. This
April, the two researchers and their colleagues reported that the Bangkok
strain of influenza virus also caused a much more severe case of flu in
selenium-deficient mice than in animals given adequate selenium in their feed.
In the new report, they explain why. Twenty-nine bases in a normally stable section of the viral genome had
mutated in the selenium-deficient mice. By contrast, there were no mutations in
the same area of the viral genome from selenium-adequate mice. It shows that
the hosts nutrition can have considerable influence on the virulence of
viral pathogens and that the virulence persists in well-nourished animals and,
presumably, people. The findings have global implications, according to Levander, who is at the
Beltsville (Md.) Human Nutrition
Research Center. While Americans generally get the recommended dietary
levels of selenium, there are pockets of selenium deficiency around the world
that might be generating harmful mutations in a number of viruses. And viruses
know no boundaries. ARS is the U.S. Department of
Agricultures chief scientific research agency. Scientific contacts: Orville A. Levander,
ARS Nutrient
Requirements and Functions Laboratory, Beltsville, Md., phone (301)
504-8504, fax (301) 504-9062, [email protected].
Melinda A. Beck, University of North Carolina,
Departments of Nutrition and
Pediatrics, Chapel Hill, N.C., phone (919) 966-6809, fax (919) 966-0135,
[email protected]. U.S. Department of Agriculture |