The surprising finding comes from a study of Australian veterans of the Second World War who are supposed to have acquired their taste for liquor in action and have enjoyed it in quantity over the 50 years since.
The study of 209 veterans whose drinking was assessed in 1982 and who were tested on a range of mental tasks nine years later in 1991 found the heaviest drinkers performed as well as the teetotallers and scans of their brains showed no sign of shrinkage due to alcohol.
In 1982, 85 per cent of the men drank at least once a week. On average, the drinkers consumed the equivalent of almost three pints of beer a day but one in five drank between four and eight pints a day, defined as a harmful level by the Australian National Health Council. A fifth drank between two-and-a-half and four pints a day, defined as "hazardous ."
By 1991, the proportion drinking regularly had fallen to two-thirds. One in 10 was drinking at the harmful level of four to eight pints and a quarter were drinking at the hazardous level of two-and-a-half to four pints.
The researchers, from the Australian National University, who report their findings in the British Medical Journal, say the heavy drinking has been attributed to comradeship, a desire to suppress memories of the war or "the atmosphere of the ubiquitous clubs of the Returned Servicemen's League."
They drank substantially more than other Australian men of the same age, yet the veterans had no sign of brain atrophy, as shown by brain scans, performed no worse on cognitive tests and their mental performance was within the normal range for men of their age.
The authors admit their results may have been distorted by the death of those most susceptible to alcohol; more than a quarter of the original group died during the nine-year study.
A spokesman for the Portman group, a watchdog set up by the drinks industry, said: " No organisation would ever recommend people can drink safely at these levels. But the study shows that some people can drink more than the recommended amount, while others should drink less."
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