Zinc is a trace mineral that supports a number of body systems, including the immune system. Recent clinical studies show that zinc can reduce the duration of a cold and may also help with chronic canker sores.

At the Heritage Center in Utah, researchers studied the effects of zinc lozenges on school-aged children. During cold season, the researchers gave 134 children, aged 12 to 18 years, either one zinc lozenge per day (preventive) or four zinc lozenges per day (therapeutic). The researchers used statistics from the previous year as the control.

At the end of the study, the average cold duration with lozenge use was seven days versus nine days with the control. The average number of colds in the season also dropped to 1.28 compared to 1.7 for the control. Of the children given zinc lozenges daily, two-thirds did not experience a cold or only had one cold that season. There was no antibiotic use or adverse events reported during the study.

The researchers concluded that zinc lozenges are a well-tolerated and easy-to-administer therapy that might significantly reduce cold-related school absences and antibiotic use.

In a second zinc study at the University Faculty of Dentistry in Turkey, researchers looked at the effects of zinc supplements on canker sores. Among 40 people with chronic canker sores, 20 were given 45 mg of elemental zinc once daily for one month, while the other 20 were given a placebo.

After one month, the canker sores were not only greatly reduced but also did not reappear for three months. The researchers recommended zinc supplements to treat individuals with chronic canker sores.

NOTE: Long-term zinc supplementation may interfere with copper absorption. Check with your health care provider for proper usage.

Sources: Am J Ther. 2003 Sep-Oct;10(5):324-9; Dent Mater J. 2003 Mar;22(1):21-9