Sydney, Sep 26 - Researchers believe that alcohol is still a potentially dangerous drug and should not be promoted as a health tonic.

They say that cardiac protection from alcohol is by no means certain and probably has been over-emphasised in recent years.

Authors of a new study also point out that there are many other health downsides from heavy drinking, and that alcohol is now widely recognised as a dangerous recreational drug.

'When viewed through the lens of two major early reviews in the mid-1980s, then Sir Richard Dolls's contributions in the mid 1990s, followed by two large meta-analyses a decade ago and two most recent overviews, the health giving properties of alcohol use become increasingly debatable,' said study author Doug Sellman, University of Otago professor.