Efficacy of Zinc Against the Common Cold Virus
Efficacy of Zinc Against the Common Cold Virus
Objective: To review the laboratory and clinical evidence of the medicinal value of zinc for the treatment of the common cold.
Data Sources: Published articles identified through Medline (1980-2003) using the search terms zinc, rhinovirus, and other pertinent subject headings. Additional sources were identified from the bibliographies of the retrieved articles.
Study Selection: By the author.
Data Extraction: By the author.
Data Synthesis: Human rhinoviruses, by attaching to the nasal epithelium via the intracellular adhesion molecule-1 (ICAM-1) receptor, cause most colds. Ionic zinc, based on its electrical charge, also has an affinity for ICAM-1 receptor sites and may exert an antiviral effect by attaching to the ICAM-1 receptors in the rhinovirus structure and nasal epithelial cells. Clinical tests of zinc for treatment of common colds have been inconsistent, primarily because of study design, blinding, and lozenge contents. Early formulations of lozenges also were unpalatable. In three trials with similar study designs, methodologies, and efficacy assessments, zinc effectively and significantly shortened the duration of the common cold when it was administered within 24 hours of the onset of symptoms. Recent reports of trials with zinc gluconate administered as a nasal gel have supported these findings; in addition, they have shown that treatment with zinc nasal gel is effective in reducing the duration and severity of common cold symptoms in patients with established illness.
Conclusion: Clinical trial data support the value of zinc in reducing the duration and severity of symptoms of the common cold when administered within 24 hours of the onset of common cold symptoms. Additional clinical and laboratory evaluations are warranted to further define the role of ionic zinc for the prevention and treatment of the common cold and to elucidate the biochemical mechanisms through which zinc exerts its symptom-relieving effects.
The common cold is one of the most frequent illnesses among humans, with an estimated 1 billion colds occurring annually in the United States. According to a 1996 survey, approximately 62 million cases of the common cold require medical attention each year, of which 27 million occur in individuals under the age of 17 years. Preschool-age children average about five to seven colds each year, compared with two or four colds annually in adults. The common cold has a significant socioeconomic impact, accounting annually for 20 million days of missed work, 22 million days of missed school, 148 million days of restricted activity, and approximately $17 billion in expenditures for physician visits.
Abstract and Introduction
Abstract
Objective: To review the laboratory and clinical evidence of the medicinal value of zinc for the treatment of the common cold.
Data Sources: Published articles identified through Medline (1980-2003) using the search terms zinc, rhinovirus, and other pertinent subject headings. Additional sources were identified from the bibliographies of the retrieved articles.
Study Selection: By the author.
Data Extraction: By the author.
Data Synthesis: Human rhinoviruses, by attaching to the nasal epithelium via the intracellular adhesion molecule-1 (ICAM-1) receptor, cause most colds. Ionic zinc, based on its electrical charge, also has an affinity for ICAM-1 receptor sites and may exert an antiviral effect by attaching to the ICAM-1 receptors in the rhinovirus structure and nasal epithelial cells. Clinical tests of zinc for treatment of common colds have been inconsistent, primarily because of study design, blinding, and lozenge contents. Early formulations of lozenges also were unpalatable. In three trials with similar study designs, methodologies, and efficacy assessments, zinc effectively and significantly shortened the duration of the common cold when it was administered within 24 hours of the onset of symptoms. Recent reports of trials with zinc gluconate administered as a nasal gel have supported these findings; in addition, they have shown that treatment with zinc nasal gel is effective in reducing the duration and severity of common cold symptoms in patients with established illness.
Conclusion: Clinical trial data support the value of zinc in reducing the duration and severity of symptoms of the common cold when administered within 24 hours of the onset of common cold symptoms. Additional clinical and laboratory evaluations are warranted to further define the role of ionic zinc for the prevention and treatment of the common cold and to elucidate the biochemical mechanisms through which zinc exerts its symptom-relieving effects.
Introduction
The common cold is one of the most frequent illnesses among humans, with an estimated 1 billion colds occurring annually in the United States. According to a 1996 survey, approximately 62 million cases of the common cold require medical attention each year, of which 27 million occur in individuals under the age of 17 years. Preschool-age children average about five to seven colds each year, compared with two or four colds annually in adults. The common cold has a significant socioeconomic impact, accounting annually for 20 million days of missed work, 22 million days of missed school, 148 million days of restricted activity, and approximately $17 billion in expenditures for physician visits.
