The Health Professionals Follow-up Study (HPFS) is a prospective cohort study of 51,529 US male health professionals. During the follow up of these men between 1986 to 2006, published in the European Heart Journal, 1,818 men were confirmed with incident non-fatal myocardial infarction (MI) – a non fatal heart attack. Among heart attack survivors, 468 deaths were documented during up to 20 years of follow up. Repeated reports were obtained on alcohol consumption every four years. Average alcohol consumption was calculated prior to and then following the MI.
The overall results show that, in comparison with no alcohol consumption, the pre-MI and the post-MI intakes of light (0.1-9.9 g/day of alcohol, or up to one small typical drink) and moderate (10.0-29.9 g/d, or up to about 2 ½ to 3 drinks) amounts of alcohol were both associated with lower risk of all-cause mortality and cardiovascular morality among these men.
The significant reductions in all-cause mortality risk (22% lower for 0.1-9.9 g/day and 34% lower for 10.0 – 29.9 g/day, in comparison with non-drinkers) were no longer present for those who drank more than 30 g/day; for this highest consumer group, the adjusted hazard ratio was 0.87 with 95% CI of 0.61-1.25.
There are a number of other informative and interesting results described from this study. First, there was little change in reported alcohol intake prior to and following the MI: drinkers tended to remain drinkers of similar amounts. Few non-drinkers began to drink after their heart attack; among heavier drinkers, there was a tendency to reduce drinking (but very few stopped drinking completely). Further there were no significant differences in outcome according to type of beverage consumed although, interestingly, lower hazard ratios were seen for consumers of beer and liquor than of wine. While the authors state that the effects of alcohol were stronger for the association with non-anterior MI's, the relative risk (versus non-drinkers) for all-cause mortality were little different: among the moderately drinking men the relative risks were 0.58 for anterior MI and 0.51 for other types of MI.
Even though exposures (such as alcohol) for cardiovascular events (such as MI) may be different after a person has an event than it was before the event, in this study the reductions in risk were almost the same. For example, both for alcohol intake reported prior to a MI, and that after a non-fatal MI, the risk of mortality was about 30% lower for moderate drinkers than it was for abstainers. This suggests that, in terms of reducing cardiovascular disease, alcohol may have relatively short-term effects, suggesting that frequent but moderate consumption (of under 30g a day for men) may result in the best health outcomes.