Even one alcoholic drink is too much for under-18s, an independent health watchdog says. The zero tolerance approach is in guidance from the National Institute for Health and Clinical Excellence (Nice).

It says there is no evidence for what constitutes safe and sensible levels of drinking for under-18s, so they should be taught not to drink. But Ed Balls, Secretary of State for Children, Schools and Families, had said last week it was wrong to rule out all drinking by teenagers.

He warned of the growing numbers of children who were drinking excessively, and added: "It is part of a sensible approach to alcohol for teenagers from time to time to have a drink at home." In France, which lacks Britain's binge-drinking culture, generations of children have been introduced to wine with meals from an early age, and appear to suffer few ill-effects later.

Nice agrees there are differing views on the right age to introduce children to alcohol. "So the recommendations focus on encouraging children not to drink, delaying the age at which they start and reducing the harm it can cause among those who do drink."

Research suggests one in five secondary school pupils regularly drinks. Andrew Dillon, the chief executive of Nice, said: "It is important that we have national guidance so we can do everything possible to delay the onset of drinking and reduce [its] harmful effects."