Does Zinc Help Fight Against Colds? Here's What Research Has to Say

Zinc is a mineral found in the body, second only to iron in its concentration—with adults containing approximately 2 to 3 grams (2). Although it’s one of the most abundant elements in the body, zinc can’t be stored in significant amounts. Thus, it must be obtained through food and/or supplementation.

In developing countries, zinc deficiency is especially common—contributing to 260,000 and 182,000 deaths in Africa and Asia in 2014, respectively. Deficiency can arise from decreased intake, inadequate absorption, increased metabolic demand, or excessive loss (3).

Zinc is involved in the following:

• Immune function
• Protein synthesis
• DNA synthesis
• Cell division
• Cell growth
• Wound healing
• Breakdown of carbohydrates
• Enhancing insulin action
• Sense of smell and taste
• Proper growth and development during pregnancy, infancy, and childhood

Zinc’s health properties were first discovered in plants. In 1869, a man by the name of Raulin—a student of Louis Pasteur—found that zinc was required for the growth and development of Aspergillus niger (a type of fungus that causes black mold).

That hypothesis was further confirmed in 1914 when Mazé found that zinc was required for the growth of corn. The health benefits of zinc remained up in the air until 1926 when Sommer and Lipman found that zinc was an essential mineral for the growth and development of sunflowers and barley (see image) (4).

Sunflowers grown with (left) and without (right) zinc.

Since 1919, researchers have speculated on the importance of zinc. Especially since it makes an appearance in egg yolks, cow’s milk, and human milk—some of the most nutrient-dense food sources in the world.

Fast forward to 1934: A groundbreaking discovery was found regarding the correlation between zinc deficiency and the stunted growth of mice…

Then it happened again in 1955 with chickens and pigs. The zinc-deficient chickens, in particular, experienced decreased growth, frizzled feathers, shortening and thickening of their long bones, and enlarged joints of the hindleg (see images) (4).

By 1972, zinc deficiency was reported to be the most common plant micronutrient deficiency in the United States. And now, it’s estimated that nearly 50% of the world’s soil is low in zinc (5). Which means that humans and animals aren’t getting enough zinc from the fruits, vegetables, and grains that they’re eating.

Knowing the negative effects of low zinc in animals automatically raises the question: How much more essential is zinc for the growth and development of humans?

In 2006, it was found that the human genome encodes nearly 3,000 zinc-binding proteins (5). These zinc-binding proteins are responsible for a multitude of cellular functions including: DNA recognition, RNA packaging, transcription of genes, regulation of cell death, protein folding and assembly, and lipid binding (6). However, in order for zinc-binding proteins to maintain structure and function, they need zinc (7).

Your body has no way to store this vital nutrient. Thus, it's all the more important to find ways to get adequate amounts of zinc into your daily regimen.

Signs of a severe zinc deficiency include:

• Acrodermatitis (a skin condition resulting in itchy red or purple blisters on the body)
• Stunted growth plates in arms or legs of children and adolescents
• Frequent infection
• Death

Signs of a low-to-moderate zinc deficiency include:

• Low immunity
• Increased likelihood of inflammation
• Increased oxidative stress
• Slow wound healing
• Trouble seeing in the dark
• Problems with the sense of taste and smell
• Loss of hair
• Poor appetite
• Suppressed functioning of neuropsychology (think: emotions, cognition, and consciousness)
• Reduced production of sex hormones in males

Zinc has proven to be extremely effective in treating colds.

In the Middle East, researchers found that zinc-deficient individuals had severe immune dysfunction and would often die of recurrent infections by the time they were 25 years old.

Luckily, research in the last 50 years has uncovered how vital this mineral is to immune function and its significant impact on the health of your immune cells. In fact, zinc is essential for the normal development and function of the cells that mediate both your innate and adaptive immunity.

Innate Immunity vs. Adaptive Immunity

Your innate immune system is the first line of defense that kicks into gear when a pathogen or foreign substance enters your body. It goes to work fighting off infection, which in turn prevents the spread of foreign substances throughout your body (8).

Zinc-dependent innate immune cells include (9, 10, 11):

• Neutrophils: The first line of defense against acute infections. These white blood cells release antimicrobial molecules and help to contain infections and inflammation to prevent the spread.
• Macrophages: These cells play a vital role in eliminating diseased or damaged cells through programmed cell death. They perform something called phagocytosis, which is the process of engulfing damaged cells (kind of like they are eating them) to remove them from circulation.
• Natural killer (NK) Cells: NK cells are a type of white blood cell that serves to contain virally infected cells and release chemicals that target infected cells for death.

While your innate immunity is non-specific (meaning it reacts to any non-self pathogens), your adaptive immune system is specific to the pathogen presented.

The downside of the adaptive immune response is that it takes a little longer to kick in. However, its effect is long-lasting and much more specific.

The two primary immune cells responsible for your adaptive immune response are B cells and T cells—both of which require zinc to function properly.

B cells and T cells work together to clear pathogens from your body. B cells are responsible for secreting antibodies that neutralize the invading cell, and then T cells come in to kill the invading cell before it has a chance to replicate (12).

Research shows that zinc, through its role in innate and adaptive immunity, can assist in alleviating viral infections as well as the common cold—especially if taken within 24 hours of the onset of common cold symptoms (13, 14).

In one study, researchers studied the effect of zinc on the respiratory syncytial virus (RSV), a common respiratory virus that causes infection in the lungs and respiratory tract.

They found that zinc was able to perform anti-viral activity by inhibiting the replication and spread of the virus (15).

Furthermore, populations that are deficient in zinc tend to have a higher susceptibility to viral attacks like HIV and hepatitis C.

It appears that zinc acts as both a direct antiviral and as a stimulant of antiviral immunity (in other words, it enhances your antiviral immune defenses) (16).

When supplementing with zinc, the following doses are recommended:

Infants

• 0 to 6 months: 2 milligrams (mg) per day
• 7 to 12 months: 3 milligrams (mg) per day

Children

• 7 to 12 months: 3 milligrams (mg) per day
• 1 to 3 years: 3 milligrams (mg) per day
• 4 to 8 years: 5 milligrams (mg) per day
• 9 to 13 years: 8 milligrams (mg) per day
• Supplementation Dose: 5 to 20 milligrams (mg) per day

Adolescents and Adults

• Males, ages 14 and over: 11 milligrams (mg) per day
• Females, ages 14 to 18: 9 milligrams (mg) per day
• Females, ages 19 and over: 8 milligrams (mg) per day
• Pregnant females, 19 years of age and over: 11 milligrams (mg) per day
• Lactating females, 19 years of age and over: 12 milligrams (mg) per day

*Note: Experts do not recommend supplementation beyond the recommended daily allowance (RDA).

If treating a cold, it’s recommended to take at least 75 milligrams of zinc per day throughout the duration of the cold (14).

Studies estimate that supplementing with zinc during a cold reduces the length of one's cold by 3.39 days (17).

There’s a wide variety of foods that contain zinc. Foods high in zinc include (18):

• Organic, Free-Range Chicken
• 100% Grass-Fed Beef
• 100% Grass-Fed Lamb
• 100% Grass-Fed Pork
• Oysters
• Crab
• Lobster
• Nuts
• Beans
• Pumpkin seeds
• Yeast

When it comes to which zinc supplement you should take, look for “chelate zinc”.

Chelate zinc enhances bioavailability as it increases the absorption of nutrients in your digestive tract (19).

In addition to chelate zinc, one should supplement with high doses of vitamin C to efficiently combat the common cold (20).

The supplement we most recommend is Native Defense. It features 6 bio-activated ingredients designed to help strengthen the body’s defenses—naturally.

The 6 cold-combatting ingredients include:

• Vitamin C (as ascorbic acid)
• Vitamin D3 (as cholecalciferol)
• Zinc (from zinc bis-glycinate chelate)
• Quercetin Anhydrous
• Elderberry Fruit Powder
• Siberian Ginseng Extract (min 0.8% Eleutherosides) (root)

As always, consult with a healthcare professional before starting any new supplement or dietary regimen.