Zinc and Your Immune System

June 14, 2016 in Foodland Chronicles, Health, Home and Garden, Immune System, Uncategorized by Joyce Bunderson

If you’re a long time reader, you know that my focus is generally on eating-style; rather than on specific nutrients. That doesn’t mean that individual nutrients are not important, especially long-established minerals. I thought that I’d mention a mineral that doesn’t get much attention – zinc. Iron, calcium, and sodium are often written about; but zinc is also an important mineral in our bodies, yet doesn’t get as much press.

Zinc is needed for many important functions in the body. Most of the 2 - 3 grams of zinc in the body is in the skeletal muscles and bones; but some is in the kidney, pancreas, retina, teeth, hair, skin, liver, blood cells, prostate, and testes. One of its main functions is in making T-cells. T-cells are an important part of our immune system; they target and destroy invading pathogens.

Tufts University’s Jean Mayer, USDA Human Nutrition Research Center on Aging, has shown that 30% of nursing-home residents have low blood levels of zinc; and that those low in zinc were at significantly higher risk of pneumonia. The body’s immune system weakens as it ages, making older adults more susceptible to infections. So it certainly follows that if a person is low in zinc they’re at increase risk of infections like pneumonia, which is a dangerous and major public health problem in older adults.

A study published in the American Journal of Clinical Nutrition (AJCN) found that the number and function of T-cells increased when those that had been zinc deficient were supplemented with zinc. The author, Meydani, said that it’s important to realize that zinc deficiency also exists in non-institutionalized older adults. It’s possible that older adults do no absorb or use zinc as efficiently as others.

Zinc deficiency is rare in the US, except in the elderly, vegetarians, those with digestive disorders and in pregnant women. If you’re in any of these groups, or are not eating a balanced diet, consider looking at the foods you’re consuming and assess if they are good sources of zinc. If you want to get zinc from your foods, you’re in luck – it is found in many foods. Red meat is a source, but if you want to minimize your intake of red meat, it’s also in shellfish and poultry. There are a wide variety of plant sources; beginning with nuts and seeds; legumes (beans); whole grains (oatmeal, quinoa). In addition, it is fortified in most breakfast cereals.

It’s important to realize that too much zinc can be toxic. Forty milligrams a day is the most that a person should take. Zinc toxicity generally suppresses the absorption of copper and iron; so that can wreak havoc on a body. Also, an individual with zinc toxicity may experience nausea, vomiting, epigastric pain, lethargy, and fatigue.

For most people, you don’t really need to think about zinc. But, if you’re elderly, pregnant, a vegetarian, or have a digestive disorder, then you could benefit from following the advice given in the study in AJCN. Pneumonia and other common pathogens can easily get the best of you if you don’t have enough zinc to produce the needed T-cells.