Zinc is vitally important in human health.
Most nutritionally oriented health care professionals recommend zinc in the treatment of the common cold. Some important questions regarding what dose, how often and what formulation should be addressed.
Zinc is the second most abundant trace mineral in the human body after iron. The adult human body contains between two to three grams of elemental zinc. Ninety percent is stored in muscles and bones.
Zinc is estimated to be involved in 2,000 different enzymatic reactions. It is involved in multiple aspects of growth and development. It is also involved in many aspects of immune function.
It estimated that up to 20% of the world’s population or 1.6 billion people have some degree of zinc deficiency. Zinc deficiency can impact proper growth and development. Zinc deficiency is also associated with mild to severe immune deficits.
The recommended daily dose for zinc is currently eight milligrams for adult females and 11 milligrams for adult males. The highest food source of zinc by a large margin is oysters.
Zinc has demonstrated direct antiviral effects. Two primary antiviral mechanisms have been demonstrated. The first is protease inhibition. Proteases are a group of enzymes that function to cleave larger viral proteins into smaller active proteins. This step is necessary for viral reproduction.
The discovery of modern pharmaceutical antiviral medicine frequently targets viral protease inhibition. Zinc functions as a natural viral protease inhibitor via direction inhibition of the protease active site. The second mechanism of antiviral activity is through inhibition of polymerase activity.
Seven studies compared zinc acetate lozenges to zinc gluconate lozenges in the treatment of the common cold. Three trials with zinc acetate showed a 40% decrease in the duration of cold in treated patients.
Four trials with zinc gluconate showed a 28% decrease in the duration of cold in treated patients. The difference between the high and lower doses of zinc in alleviating cold duration was not significant. Additionally, lozenge composition and dosage schedule were deemed important.
Another randomized trial involving 100 employees of an American medical clinic with cold showed an improvement in the zinc-treated group. Half the sick employees took a zinc lozenge supplying 13.3 milligrams of elemental zinc every two hours as long as they had symptoms. The other half took placebo. Cold symptoms lasted an average of 4.4 days in the zinc-treated group, compared to 7.6 days in the placebo group.
Zinc supplementation potentially reduced cold duration by an average of 2.25 days in a review of 10 studies
The ingestion of large doses of zinc for prolonged periods of time suppresses the immune system in much the same way as zinc deficiency. Large dose, beyond 150 milligrams per day of zinc cause transient nausea in many people.
Highly soluble and ionizable forms of zinc in the forms of lozenges and liquids are probably the best compounds to use. The earlier zinc supplementation is started to better. Within 48 hours, but probably within 24 hours of the first onset of cold symptoms is best. The better the solubility the higher degree of ionization of the zinc compound to produce a larger concentration of positive charged zinc ions.
This appears to better to produce a local effect at the site of viral infection and inhibiting pathogenic inflammation created there. An “upregulation” of the immune system and white blood cells can also occur but is realistically a little slower to develop than the immediate antiviral effects.
Taken together, the direct antiviral activity and the immune enhancement effects both contribute to the use of zinc in the treatment of the common cold. It is further worth mentioning that the types of zinc compounds with the highest degree of solubility and ionization are indeed the type of zinc compounds that reveal the best effects in treatment of the common cold. Zinc acetate, zinc gluconate and zinc sulphate are among these compounds.
An elemental dose between 5 and 25 milligrams of zinc can be recommended. Repeated dosing every one to four waking hours is best. Taken for a minimum of three days to up to seven to 14 days or when symptoms disappear is reasonable.
Side effects of nausea and upset stomach are common and can occur. Reducing the dose and taking following the intake of food may help. Larger daily doses beyond 75 to 150 milligrams of elemental zinc are not recommended for most people. Taking high doses beyond two weeks of the first onset of cold symptoms is not recommended.
Of course, it is advised to consult a licensed health care professional for specific dosing and treatment instructions. Also, if pregnant, nursing or under the age of 12 consult a licensed health care practitioner for specific guidelines.
The information provided in this article does not, and is not intended to, constitute medical advice. All information and content are for general information purposes only.
This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.