What is Zinc and why we need it for our bodies.

Basic Description

From a food standpoint, zinc may be a less familiar dietary mineral than iron or calcium or sodium, but it is no less important to our metabolism or our health. Like magnesium, zinc is used as a cofactor by a number of critical enzymes. (This "cofactor" status of zinc means that zinc participates directly in the activity of the enzymes.) In fact, more than 300 zinc-dependent enzymes are currently known. Even a mild dietary deficiency of zinc can have far-reaching health implications. Immunity, reproduction, skin health, and vision are just some of the areas that can be affected. The importance of this mineral to multiple body systems makes it even more important for us to get an adequate amount of zinc in our daily diet. This task can be a very challenging one.  Like sodium and potassium, or calcium and magnesium, zinc and copper have overlaps in transport and metabolism. For this reason, balancing dietary zinc and copper sources may help prevent deficiency or excess of either mineral.

Role in Health Support

Immune Function

Diets low in zinc can induce measureable reductions in the activity of the immune system. These reductions occur relatively quickly—in as few as four weeks after starting a low-zinc diet—and are reversible upon getting zinc back into the body. This experimental low-zinc diet only contained 2-3.5 milligrams of zinc per day, or less than you would have in a single serving of our Mediterranean-Style Salad. It appears that elderly individuals are especially prone to developing reduced immunity related to poor zinc nutrition. Even in this at-risk population, restoring zinc status appears to reverse the detrimental changes within weeks. One research group has gone so far as to recommend using a Mediterranean-style diet—a diet very similar to the World's Healthiest Foods approach—to protect against zinc deficiency in elderly individuals. We couldn't agree more.

Skin Health

Researchers have been able to induce acne symptoms in young men by feeding them diets deficient in zinc. This effect occurs surprisingly quickly, with one research group demonstrating a significant change in skin health within 12 days of depleted zinc foods. Other researchers have been able to demonstrate a number of other skin and related symptoms, including facial rash, foot fungus, and canker sores. Again, each of these changes was reversed when zinc was brought back into the diet. While we don't want to overgeneralize about the significance of this study—and are by no means saying that most acne is caused by zinc deficiency—it does suggest that too little zinc from a meal plan can be a factor in compromising skin health, and that it's worthwhile building your zinc intake up to recommended levels in order to support the health of your skin.

Sensory Organs

Acute depletion of zinc can causes loss of the sense of taste and appetite. The level of zinc deficiency necessary to cause these changes appears to be more severe than the immune system changes reported above, and is often related to another factor such as cancer treatment or anorexia. One research group recently estimated that about 15% of elderly people who lost their sense of taste did so due to zinc deficiency, and some others did so due to more serious conditions; so make sure to report this symptom to your doctor if you develop it. Like the other symptoms related to zinc deficiency, this change in sense of taste appears to be reversible in the majority of people who get back to normal zinc status. Here are a couple of recipes—Braised Red Curry Lamb and Vegetables as well as Healthy Chef's Salad with Walnuts and French Dressing—that should help to combat zinc-related loss of sense of taste, both by acting as good sources of zinc, and by including a good zing of spices. Zinc is also critical to vision. It works together with vitamin A to help sense light and to send nerve impulses to the brain. Although we don't currently know how much of age-related vision loss is due to zinc deficiency, researchers have shown that zinc levels in the retina (the part of the eye that sees light) decline in tandem with vision loss.

Male Reproductive Health

Advanced deficiency of zinc can impair motility and number of sperm. In one study, young male volunteers ate a diet with only 10% of the Daily Value requirement (15 milligrams) for a little over a month. Researchers measured sperm quality and quantity before and after the zinc-deficient diet. This study demonstrated that even brief periods of severe zinc deficiency can lead to measureable changes in sperm composition and quantity. Studies correlating diseases known to impair zinc nutrition with reduced fertility seem to second this conclusion. Here's a recipe—our 7-Minute Sautéed Crimini Mushroom—rich in zinc and selenium, another nutrient necessary for proper sperm production.