Eating More Words About Cold Cures

Only a short time ago we had to admit that Echinacea seems to help the common cold – prevents it, or shortens it. This was shown in a meta-analysis of 14 well-conducted published studies. Now another meta-analysis has been published – but this time for vitamin C, long scorned as being little better than a placebo.

The Cochrane review was restricted to placebo-controlled trials testing at least 200 mg vitamin C daily that included a total of 11,350 participants. Regular intake had no effect on the frequency of common colds in the general population. The duration and severity were very slightly reduced, although this was hardly ‘clinically useful’. However, in people exposed to extreme physical stress or cold (e.g. long-distance runners or skiers) the incidence was halved by regular supplementation; this group included schoolchildren in a ski-camp. When given after the onset of symptoms there was no consistent effect, even with very high doses.

These findings were not as clear cut as one would like to see. Although the overall results are negative, there are special circumstances when it might be worth taking vitamin C daily to ward off a cold, or reduce the length/severity of one, if caught. There were virtually no side effects reported in the review, so giving it a try is probably justified. (No mention of summer colds – the worse kind, in my opinion – in the review.)