You probably know which foods are rich in vitamin C, calcium, and even iron, but what about zinc? Many of my clients only seek out zinc in the form of lozenges when they have a sore throat. But according to a new study published in the Journal of Nutritional Biochemistry, this key mineral should be top of mind.
Researchers say that zinc deficiency, which can develop with age, leads to a weakened immune system and increased inflammation, a known trigger of aging and chronic illnesses, including heart disease, cancer, and diabetes. The study found that zinc metabolism was impaired in older animals, who showed signs and symptoms of deficiency despite consuming a diet that contained adequate amounts of the mineral.
Zinc is needed to support a proper sense of taste and smell. It's also neccessary for immune function, including the activity of T-lymphocytes, a type of white blood cells. And it’s needed to form DNA and cell structure, which means too little can hinder the body’s ability to heal properly.
But consuming too much can also be risky. Excess zinc has been shown to suppress the immune system and lower “good” HDL cholesterol, the type that helps slash the risk of heart disease. Taking too much can also interfere with absorption of other key nutrients, such as iron and copper, and cause GI problems, including nausea, pain, and diarrhea.
To get enough, think food first. Some of the best sources include seafood (especially scallops, shrimp, lobster, and crab), yogurt, cooked spinach, mushrooms, pumpkin and sesame seeds, lean meat, and beans.
If you think you may need a supplement, talk to your doctor or dietitian before you make a purchase. The tolerable upper intake level (UL) for zinc is 40 milligrams. In a nutshell, UL essentially means that exceeding this amount between both food and supplements combined could lead to adverse effects, but I’ve seen supplements in markets and online in doses higher than this.
Bottom line: This is one mineral to start paying attention to, but to reap the benefits, it’s important to strike the right balance.
Cynthia Sass is a registered dietitian with master's degrees in both nutrition science and public health. Frequently seen on national TV, she's a SHAPE contributing editor and nutrition consultant to the New York Rangers and Tampa Bay Rays. Her latest New York Times best seller is S.A.S.S! Yourself Slim: Conquer Cravings, Drop Pounds and Lose Inches.