Swine flu alerts have authorities concerned about the immune systems of both people and pigs. So far, no pigs have contracted the malady named after them. Only people have fallen victim to this new virus. Consequently, if swine could speak English, they would be calling this virus the human flu or the 2009 H1N1 virus.

This type of virus can infect people and pigs. It is not known whether pigs can handle the 2009 virus better or worse than we can. But, whether pig or person, keeping the immune system healthy is the best defense.

Question: How does the immune system protect us?

Answer: The immune system is an extremely complex combination of barriers, highly specialized cells with names like natural killer cells, special proteins that identify invaders and trigger protective actions, and even cells that remember how to respond if the same invader shows up again.

When the immune system goes into alarm mode, a series of orchestrated actions takes place to destroy the invaders and mop up the mess left after the war is over. That's why we feel so sick. There is a war going on inside.

Q: How can we keep the immune system fit?

A: Good nutrition can help to keep the immune system command centers and infantry strong and alert. But, that doesn't mean that it helps to megadose on vitamin and mineral pills. The immune system seems to rely mostly on maintaining the right balance of nutrient supply with nothing out of proportion to its proper level.

Being deficient even in calories or protein is known to weaken the immune system. Probably a deficiency of any essential nutrient can compromise the immune system. But it is clear that normal levels of folic acid and vitamins A, B-6, B-12, C, D and E are especially essential for a good immune response.

Similarly, the minerals selenium, zinc, copper and iron are all critical elements in a well-coordinated battle with an invading virus.

But before you go overboard on nutrients, consuming too much of some essential nutrients can strengthen an invader.

The current science on boosting the immune system supports getting your nutrients by eating a balanced diet and possibly by moderate use of vitamin and mineral supplements.

Other lifestyle basics—such as getting adequate sleep and exercise and managing stress well—all help to promote good immune function.

If you are wringing your hands over the current flu alert, try washing them instead. Even if the pandemic flu warnings prove to be a false alarm, at least we are getting a good refresher course on how to not share viruses with each other.

Joannie Dobbs, Ph.D., C.N.S., and Alan Titchenal, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services. “;Health Options”; appears every other Monday.