You’ve heard of senile dementia, but did you know there’s a name for increasing immune dysfunction associated with aging? It’s called “immunosenescence,” in other words, “senile immunity,” and it often becomes noticeable beginning in the mid-fifties.

According to a recent article in the Journal of Nutritional Biochemistry, “aging of the immune system is characterized by progressive dysregulation of immune responses, resulting in increased susceptibility to infectious diseases, impaired vaccination efficacy and systemic low-grade chronic inflammation.”

But how much of immunosenescence is an inevitable part of aging, and how much can be attributed to the two causes of disease, nutrient deficiency and toxicity?

Turns out a lot of it may have to do with zinc deficiency.

According to the National Institutes of Health older people are likely to be deficient in zinc; a government survey found that even those elderly taking supplements were apt to be low. As we age, we tend both to have more difficulty absorbing zinc, and to get less zinc in our diets. Since the average American diet is already low in zinc, it’s not surprising to find older folks deficient.

Vegetarian elderly are at an even higher risk since vegetarian diets typically contain 10 to 30% less zinc than non-vegetarian diets.

But is zinc deficiency causing immunosenescence?   Quite a few scientists believe it is at least a major factor. And supplementary zinc has been shown to help reverse it.

In a 2007 study, for example, a group of older men and women were given either 45 mg of zinc per day or a placebo for one year. In that year, the supplemented group had a total of 7 infections compared with the placebo group’s 35; and when the zinc-takers got infections, they had milder symptoms. Although the group as a whole was borderline zinc deficient when the study began, even those who had been in the normal range benefited from supplementation (indicating that what is considered normal is not necessarily optimal).

Raymond Francis recommends at least 30 mg/day of zinc for most people, and many, including those over 55, would do well to take more. Since zinc is not stored well in the body, and it is lost in sweat, during stress, and when facing an immune challenge, there are times when everyone would benefit from taking extra zinc.

In very large doses, zinc can suppress another important nutrient, copper. In the above study, 45 mg of zinc was given daily for a full year without lowering copper, however if you take more than 50 mg of zinc long term, you should balance it with 2 or more mg of copper.