Can zinc stop a cold in its tracks? While zinc boosts your immune system, there’s no evidence it has this particular superpower.
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But don’t give up on zinc — what it’s good for is even more impressive.
“This important nutrient plays key roles in fighting germs, healing wounds and more,” says registered dietitian Julia Zumpano, RD, LD.
Zumpano walks us through zinc’s benefits and how to ensure you get enough from the foods you eat.
What is zinc?
Zinc is a trace mineral, which means your body only needs small (trace) amounts to stay healthy. It’s an essential nutrient, which means your body doesn’t produce it on its own and doesn’t store any excess zinc you may consume.
So, what does zinc do for your body?
“Zinc is an antioxidant, which helps prevent cell damage that contributes to heart disease, cancer and other serious health conditions,” says Zumpano. “Zinc exists in cells throughout your body.”
Zinc also plays important roles in how your body grows and develops. This includes gene expression (how your genes function) and the creation of DNA and protein (a process known as synthesis).
Zinc benefits
Let’s take a look at zinc’s potential health benefits.
Shortens a cold
Zinc helps make immune system cells that fight germs. While zinc lozenges or supplements won’t keep you from catching a cold, they may help you get over a cold faster.
A 2021 systematic review of 28 studies found that using zinc lozenges, gels or nasal sprays may help people feel better two days sooner than those who didn’t use zinc. But zinc didn’t lessen the severity of cold symptoms. And be on the lookout for side effects, including bad taste and nausea.
If you want to try zinc to feel better faster, Zumpano recommends sticking to lozenges.
“In rare instances, people who use zinc nasal sprays lose their sense of smell — sometimes, permanently,” she warns.
Protects eyesight
Studies suggest that taking 80 milligrams (mg) of a zinc supplement, along with other vitamins for eye health, can lower the risk of advanced age-related macular degeneration (AMD) and vision loss by 25%. People with AMD are at risk of losing their eyesight if the disease progresses.
Your retinas (the part of your eyes that converts light into the signals your brain uses to create images) have a high concentration of zinc. Extra zinc in the form of supplements may help protect your retinas against harmful free radicals that cause cell damage.
Lowers blood sugar and cholesterol
For reasons that aren’t clear, people with Type 2 diabetes are often low in zinc. Some experts believe these low zinc levels may make the disease progress quickly.
Different studies suggest that zinc may lower blood sugar and high cholesterol in people with Type 2 diabetes. These conditions increase your risk of life-threatening strokes and heart disease. A 2021 review of research shows that zinc may also improve blood sugar levels in people with gestational diabetes.
Promotes wound healing
Research shows that oral zinc supplements may speed the healing of diabetes-related foot ulcers and other skin ulcers.
And zinc oxide that you apply directly to the skin (topical) is a proven diaper rash treatment. It also acts as a moisture barrier, helping protect your baby’s sore bottom from additional irritation.
Improves sperm quality
Initial research shows that men who experience infertility may see an improvement in sperm quality after taking a supplement with zinc.
But Zumpano notes that more large-scale studies are needed to fully understand its role.
How much zinc per day should you get?
The amount of zinc (in milligrams) you need each day depends on your age, sex and whether you’re pregnant or breastfeeding.
Source: National Institutes of Health
Foods high in zinc
Certain types of seafood, meats and poultry are good sources of zinc. There are also zinc-fortified products, like breads and cereals.
Foods with the highest amounts of zinc include:
- Oysters
- Beef sirloin
- Blue crab
- Fortified cereals
- Pumpkin seeds
- Pork loin
- Turkey breast
- Cheddar cheese
- Shrimp
- Lentils
“It’s usually easy to get the recommended amount of zinc without supplements,” Zumpano clarifies.
Should I take a supplement?
Even though most of us get enough zinc in our diets, there are some exceptions.
Reasons to take zinc supplements include:
- You had bariatric surgery or have inflammatory bowel disease (IBD), like Crohn’s disease or ulcerative colitis. These situations affect how much zinc your body absorbs and increase the amount of zinc you lose when you pee.
- You follow a plant-based vegetarian or vegan diet that doesn’t include meat, the primary source of zinc. While beans and whole-grain products have zinc, they also contain antioxidants called phytates that interfere with how your body absorbs zinc.
- When you’re pregnant and breastfeeding, zinc supplements support healthy infant development.
- Your child has sickle cell disease. Medications can affect zinc absorption, so your child may need supplements.
- You have substance use disorder (SUD). Substance use, particularly alcohol, lowers zinc absorption while causing you to lose more zinc in pee.
“Almost all multivitamins, as well as many calcium and magnesium supplements, contain zinc,” shares Zumpano. “Read the label to know how much zinc you’re getting in a day when factoring in food sources.”
You may see different types of zinc on supplement labels, including zinc sulfate, zinc acetate and zinc gluconate. They’re all zinc. And no evidence suggests one form is better for you than the other. Zinc is also a common ingredient in denture adhesive creams and many all-natural cold products.
If you’re taking an antibiotic or a rheumatoid arthritis medication called penicillamine, zinc supplements may lessen the effects of those drugs. Zumpano stresses the importance of talking to your doctor before starting zinc or any other supplement.
What happens if you take too much zinc?
There’s a good chance you’re already getting enough zinc through the foods you eat each day.
If you’re worried about a zinc deficiency due to dietary choices or health conditions, your provider can order a blood test to check your zinc levels.
Getting too much zinc through supplements can cause side effects, like:
- Copper and magnesium deficiencies
- Headaches
- Loss of appetite
- Low HDL (“good” cholesterol) levels
- Upset stomach, including nausea, vomiting and diarrhea
- Worsening immune function, which can lead to increased infections
“Use caution and talk to your healthcare provider before taking a zinc supplement,” stresses Zumpano. “You don’t want to risk getting too much and having side effects.”