A friend of mine insists that downing honey by the heaping tablespoon at the first sign of a cold will alleviate the symptoms, shorten the duration of the cold, or prevent it entirely - any and all of the above. I have found a few sites online (that are rinky-dinky to the point where they aren't worth linking to) that tout honey similarly as the magical cold cure. Is it really better than pharmaceutical remedies? If not, is it better than not using a remedy at all?
I found no evidence for honey helping colds. Cochrane found limited evidence for honey helping in acute coughs in children, and no evidence for honey helping chronic coughs in children.
The Cochrane Collaboration do meta-analyses of health studies - they gather all of the published scientific evidence on a topic, and use careful statistical techniques to try to work out which way the evidence points.
While they don't have a general purpose study on honey's affect on the common cold, there were two studies of honey's affect on children with coughs - one for acute and one for chronic.
In the first analysis, they could only find one small study with any good evidence:
Note the comparison here is to "no treatment" rather than placebo or regular cough medicine.
In the second analysis, they looked for the affect on chronic non-specific coughs, which were defined as:
Four weeks is a long time - this is beyond your typical common cold.
What they found was that there was no good evidence either way for chronic coughs.
Cough is certainly a symptom of a cold, and honey has been found to help with that: http://www.mayoclinic.com/health/honey/AN01799 and http://www.umm.edu/altmed/articles/pharyngitis-000129.htm both cite a 2007 (peer reviewed and published) study.
The idea behind eating honey is kind of like gradually vaccinating the body against allergens, a process called immunotherapy. Honey contains a variety of the same pollen spores that give allergy sufferers so much trouble when flowers and grasses are in bloom. Introducing these spores into the body in small amounts by eating honey should make the body accustomed to their presence and decrease the chance an immune system response like the release of histamine will occur [source: AAFP]. Since the concentration of pollen spores found in honey is low -- compared to, say, sniffing a flower directly -- then the production of antibodies shouldn't trigger symptoms similar to an allergic reaction. Ideally, the honey-eater won't have any reaction at all.