The use alcohol as a beverage by humans dates back at least 9000 years.  People in almost every country on earth drink alcohol.  Naturally we want to understanding the health implications of drinking alcohol. 

The study of the health implications of alcohol is one of the most studied of aspects of health, disease and wellness.  Scientists have tied plenty of health hazards to alcohol.  Among other conditions, it increases the risk of certain cancers, stroke, and liver disease.  Heavy drinking has conclusively been shown to harm health, but there is still discussion surrounding the healthful benefits of alcohol. For instance, although light drinking has been shown to increase cancer risk, there is also evidence that light drinking could protect the heart.

The latest study to look at the relationship between heart health and alcohol concludes consistency in the way you drink alcohol may be the key heart health alcohol consumption.  Shifting drinking patterns across the years might increase the risk of cardiovascular disease.

This recent study found that people who drank one or fewer drinks per day had lower cardiovascular risk than people who drank more, as well as people who abstained completely. Could a small amount of alcohol be heart protective?

Alcohol and the heart revisited

However, the increased cardiovascular risk seen in people who do not drink at all may not be what it seems. Some have made the point that individuals who do not drink now might still have been drinkers in the past.  In other words, someone who hasn’t touched a drop for months may have still been a heavy drinker for many years in the past.

The latest study, which is published in the journal BMC Medicine, set out to clear up this query by comparing rates of coronary heart disease (CHD) in individuals who have never drunk and those who used to drink but quit.  The study used long-term data to distinguish between persistent non-drinkers and former drinkers and test the theory that only former drinkers have an elevated risk of CHD.  To investigate whether the theory held true, the researchers examined data from 35,132 people taken from six earlier studies in the U.K. and France. The data included self-reported weekly alcohol intake across a period of 10 years. Of the 35,132 people, 1,718 (4.9 percent) developed CHD. In 325 of the cases (0.9 percent), the person died.

Did persistent non-drinkers have a lower cardiovascular risk than former drinkers, as hypothesized?  The study did not find this to be the case, but it did observe a sex-related difference. Among consistent non-drinkers, women showed higher risk of developing CHD compared to consistently moderate drinkers, but their male counterparts did not.”  CHD risk was the highest for former drinkers (6.1 percent had a CHD event), while the risk was lowest in consistently heavy drinkers (3.8 percent experienced a CHD event).  However, the scientists make it clear that because there were so few people who drink heavily in the data set, the apparent reduction in risk should not be taken as fact.

The study did show that individuals who drank sensibly (that is, in line with UK guidelines) over a 10 year period had a lower risk than those who ever drank, those wh inconsistently drank in moderation and those who had stopped drinking.

Consistency and fluctuation

These findings suggest that fluctuations in drinking patterns over time are associated with an increase in CHD risk. It is likely that changes in drinking patterns mirror life events, such as long periods of ill health or other life stresses, including divorce, bereavement, or unemployment.  This additional factor – drinking consistency – complicates the analysis of the study alcohol and health and makes it difficult to draw meaningful conclusions.  We all have long, complicated lives, wherein a myriad of influences increase or decrease health risks.

To investigate the effect of drinking consistency further, the researchers split the data into age groups.  When the study participants were viewed by age group the researchers found that the elevated risk of CHD among inconsistently moderate drinkers was observed in participants aged over 55, but not those aged below.  It may be that the older group experienced lifestyle changes, such as retirement, which are known to co-occur with increases in alcohol intake and that these could have played a role in the differing risk.

As with any study that looks at alcohol intake and health, there are unavoidable gaps and plenty of room for future improvements. As with any study of this type the cause and effect of drinking alcohol cannot be absolutely proven. In the long line of studies investigating long-term alcohol intake and heart health, this study adds another slice of information but still leaves plenty of questions unanswered.

Thanks to humanity’s fascination with alcohol, studies unpicking its potential benefits and pitfalls are sure to continue.