Two papers based on the personal experience of male medical doctors, whose mortality had been observed over a period of 10 to 13 years after they had reported their drinking habits have given somewhat different results. Several factors may have contributed to the apparently different results. Others are differences in the adequacy of the standardization for smoking and in the age distribution of the doctors studied, changes in drinking habits in the course of observation, and, to some small extent, possibly chance. Similar differences have been observed in many other studies , but doctors have seemed of special interest, as it might have been hoped that they would report their habits more accurately than the general public who, experience has shown, substantially understate the amount they drink, as judged by figures for the amount sold , . The American authors note that other health professionals have been found to provide reliable reports of alcohol use6, but there has been so much disapproval of the use of alcohol by religious groups in the US that it would not be surprising if American doctors tended to understate their alcohol consumption.
Some conclusions are clear.
First, some reduction in total mortality in middle and old age can be expected with consumption of one alcoholic drink a day, and some increase can be expected with the consumption of six or more a day. Thirdly, despite the claims that have been made for a specific effect of wine, the totality of the evidence shows that all forms of alcohol have similar effects , as is to be expected from the experimental findings with ethanol. In so far as there has been greater benefit reported when wine is the principal type of alcoholic beverage, this may be because wine drinkers tend to spread their consumption out through the week, rather than concentrating it over one or two days. Fourthly, the balance of risk and benefit will not be the same in all countries and will shift sharply away from benefit at any level, in communities in which vascular disease is rare and the risk of physical violence is high18. Much, however, remains to be clarified.