BBC Future has sifted through the evidence to find out

Yet the apparent benefits of many of the treatments we take for granted today – such as dosing up on vitamins or snorting salt water – evaporate under scrutiny. So what works and what doesn’t? BBC Future has sifted through the evidence to find out.

Don’t dose up on vitamin C (but perhaps boost your zinc)

(Thinkstock)

(Thinkstock)

“The first thing that many people will try is to supplement their diet with vitamins C and D,” says Michael Allan at the University of Alberta in Canada, who recently reviewed the evidence for the most popular remedies. “But the evidence is terrible for those.” Dosing up on vitamin C has been shown to mildly protect people under great physical strain– such as marathon runners – from falling ill, but for the average person it reduces your risk by just a 3%. “If an adult gets two colds a year, you’ll only avoid one cold in 15 years,” says Allan.

Zinc lozenges may have a firmer footing. Based on three clinical trials, Allan says that children taking regular zinc supplements will suffer roughly 1 to 1.5 fewer colds a year, on average – compared to the six to eight that is normal for school children. There is also some evidence that it can reduce the duration of a cold by a day or so. Given that zinc tastes unpleasantly astringent, and you would need to take it all year round for the full benefit, Allan is unsure if he would recommend it for general use.

Do enjoy a tipple… maybe