Does zinc really help ease the symptoms of the common cold? People have been asking this question since zinc was first suggested as a cold treatment by researchers in 1984. Since then, studies have produced conflicting results that have left consumers wondering whether zinc is a valuable addition to the medicine cabinet or a waste of money.
A new systemic review published in the Cochrane Library looked at data from 15 research trials which studied 1,360 patients with colds. Based on the consolidated study results, researchers now believe that taking zinc syrup, lozenges, or tablets the first day you have cold symptoms can help ease cold symptoms and make the cold go away faster. The studies showed that seven days after catching a cold, more people who took zinc were free of symptoms than people who did not take zinc. The study also showed that children who took zinc missed fewer days of school. These children also had less need for antibiotics. This is significant because taking too many antibiotics that are not needed can result in resistance to the antibiotics, which means they will stop being effective.
Zinc is a metal which is considered to be an “essential trace element”. It is said to be “essential” because it is necessary for good health. It is a “trace element” because it is only needed in very small amounts. Zinc is used by the body for normal growth and maintenance. It is necessary for the function of the immune system, wound healing, blood clotting, the thyroid gland, and is also active in many other systems in the body. Zinc is also important for good vision and is found in high concentrations in the retina, or inner lining of the eye where images are focused.
In addition to being promoted to ease the common cold, zinc supplements are effectively used to raise the levels of zinc in people who have a zinc deficiency. Low zinc levels are rare in the United States, but zinc deficiency is more common in other parts of the world. Zinc may also be effective as a treatment for acne, osteoporosis, age-related macular degeneration, ADHD, and many other conditions. However, research has not conclusively shown zinc to be a cure or proven treatment for any of these other conditions.
Zinc supplements in the form of syrup, lozenges, or tablets are considered to be safe at the recommended dosage. Taking larger doses of zinc can cause problems with the amount of iron in the blood, and doses larger than 10 grams (very large doses) can be fatal. Zinc is also been marketed as a nose spray to treat cold symptoms. In 2009, the U.S. Food and Drug Administration (FDA) issued an alert to warn consumers that nose sprays containing zinc have not been shown to be effective in treating cold symptoms and may cause a permanent loss of the sense of smell.
Researchers still do not know how zinc works to ease the symptoms of the common cold. Further study is needed to determine the most effective dose and length of treatment for cold symptoms. Researchers hope to continue to study the effectiveness of zinc supplements to reduce cold symptoms in people with asthma. They also want to do more research in low-income countries where levels of zinc may frequently be too low.
Sources:
Science Daily
National Institutes of Health: Medline Plus
U.S. Food & Drug Administration