A teaspoon of honey before bed seems to calm children's coughs and help them sleep better, according to a new study that relied on parents' reports of their children's symptoms.
The folk remedy did better than cough medicine or no treatment in a three-way comparison. Honey may work by coating and soothing an irritated throat, the study authors say.
"Many families are going to relate to these findings and say that grandma was right," said lead author Dr Ian Paul of Pennsylvania State University's College of Medicine.
The research appears in this month's Archives of Paediatrics and Adolescent Medicine.
US health advisers have recently warned that over-the-counter cough and cold medicines should not be used in children younger than 6, and manufacturers are taking some products for babies off the market.
Three paediatricians who read the study said they would tell parents seeking alternative remedies to try honey.
They noted that honey should not be given to children under age 1 because of a rare but serious risk of botulism.
Researchers recruited 105 children with upper respiratory infections from a clinic in Pennsylvania.
Parents were given a paper bag with a dosing device inside.
Some were empty. Some contained an age-appropriate dose of honey-flavoured cough medicine containing dextromethorphan. And some contained a similar dose of honey.
The parents were asked about their children's sleep and cough symptoms, once before the bedtime treatment and once after. They rated the symptoms on a seven-point scale.
All of the children got better, but honey consistently scored best in parents' rating of their children's cough symptoms.
"Give them a little time and they'll get better," said Pat Jackson Allen, a professor at Yale University School of Nursing.
The study was financed by a grant from the National Honey Board, an industry-funded agency of the US Department of Agriculture. Dr Paul said the agency had no influence over the study design, data or results.