A hot lemon and honey drink is good for colds

There is little evidence either for or against, but this may have some truth. There is widespread belief in the community, at least in Australia, in the virtues of lemon and honey. It would appear, however, not to have been formally studied. Such a mixture does have characteristics that could alleviate symptoms, such as the temperature of the drink, since it is usually taken warm or hot and so influences mucous membranes; or its taste, as lemon has the ability to stimulate salivary flow and lubricate an otherwise dry mouth and pharynx.

There is no evidence that the vitamin C content of lemon (about 80 milligrams per 100 grams) would have any beneficial effect. There are many other components in lemons, and some of these could potentially have a medicinal effect.

On the question of unique healing properties of honey, it is true that honey is simply another form of the simple sugars (fructose, glucose and sucrose). However, from time to time honey acquires biologically active substances from the flowers on which the bees feed. Occasionally there are outbreaks of illness due to the presence of harmful substances in honey that have been obtained from flowers. It is quite conceivable that honey may sometimes contain medicinally useful compounds collected by bees from some flowers in the same way as those that cause illness, but so far there has been no scientific evidence to support this.