Drop in official figures comes despite warnings that the NHS is under strain from the number of drink-related admissions

Three in five adults say they drank alcohol in the past week, continuing a decline recorded by official figures over the past seven years.

In 2005, 72% of men and 57% of women in Britain said they had drunk alcohol in the seven days before being interviewed, compared with 64% and 52% respectively last year, figures that were also down on 2011.

The Office for National Statistics found that the proportion of people drinking frequently (five days or more in the past week) also dropped, again with figures below those in 2005.

The decline comes despite warnings that the NHS is under strain from the number of drink-related admissions.

Alcohol Concern has warned that the problems caused by over-consumption are at a historic high.

The charity's chief executive, Eric Appleby, said: "Any reduction in the number of people drinking is welcome; however, large numbers of men and women continue to drink regularly at levels which seriously risk their health.

"The reality is we're facing historically high levels of health problems caused by alcohol misuse, with over a million alcohol-related hospital admissions each year, and we're one of the few European countries where liver disease is on the increase."

He called for restrictions on availability and advertising of alcohol as well as an end to "pocket-money prices".

The amount of alcohol drunk by respondents' on their heaviest drinking day in the week before being interviewed has also fallen since 2005. Last year, 19% of men drank more than eight units on their heaviest drinking day and 11% of women drank more than six units – levels of consumption sometimes defined as heavy drinking or binge drinking. The figure was up one percentage point for men on 2011, because of a slight increase among over-65s, but down one percentage point among women. Both figures are four percentage points down on 2005.

The ONS warned that the statistics should be viewed with caution. "Social surveys consistently record lower levels of consumption than would be expected from data on alcohol sales," a spokesman said.

"This is partly because people may consciously or unconsciously underestimate how much alcohol they drink. Drinking at home is particularly likely to be underestimated because the quantities consumed are less likely to have been measured and also more likely to be larger than those dispensed in licensed premises."