Moderate drinkers fare best in cardiovascular and total mortality
As soon as a new study confirms that moderate consumption of alcoholic beverages compared to abstinence is associated with a lower cardiovascular disease risk, critics challenge these findings referring to the “sick quitters” in the reference group. Their main argument is that in the reference group, former drinkers who quit drinking for health reasons will be misclassified as abstainers. The current study with nearly 2 million participants refutes this argument and confirms the J-shaped association of moderate consumption of alcoholic beverages with significantly less heart disease compared to non-drinkers and heavy drinkers.
The most comprehensive study investigating the relation between alcohol consumption and risk of cardiovascular disease to date was carried out by UK researchers (University of Cambridge and University College London). Their large-scale study followed 1.93 million adults (men and women) without cardiovascular disease at baseline for 6 years. Using records of self-reported alcohol consumption for 5 years before study entry, the team was able to classify 14.3% of the participants as nondrinkers, while 3.7% were former drinkers, 11.9% were occasional drinkers, 61.7% were moderate drinkers, and 8.4% were heavy drinkers. (Alcohol consumption status was missing for 16.1% of the cohort). Moderate drinking was defined as consumption within existing UK weekly/daily guidelines of 21/3 and 14/2 units for men and women, respectively (1 UK drinking unit = 8 g of alcohol, which is the equivalent of 24 g of alcohol/day for men and 16 g of alcohol/day for women).
114,859 individuals received a cardiovascular diagnosis during follow-up.
Classic J-shaped associations were observed for cardiovascular disease (all and fatal) and all-cause mortality and moderate drinkers. Non-drinkers, former drinkers and heavy drinkers had an increased risk compared to moderate drinkers: Non-drinking in comparison with moderate drinking was associated with an increased risk of:
- unstable angina (+33%),
- myocardial infarction (+32%),
- unheralded coronary death (+56%),
- heart failure (+24%),
- ischaemic stroke (+12%),
- peripheral arterial disease (+22%) and
- abdominal aortic aneurysm (+32%).
At the same time, heavy drinkers (exceeding the drinking guidelines) – compared to moderate drinkers – had an increased risk of:
- unheralded coronary death (+21%),
- heart failure (+22%),
- cardiac arrest (+50%),
- transient ischaemic attack (+11%),
- ischaemic stroke (intracerebral) (+33%)
- cerebral haemorrhage (+37%) and
- peripheral arterial disease (+35%).
In addition, compared to moderate drinking, the risk of experiencing some cardiovascular event/disease was higher in former drinkers.
Former drinkers had a higher risk of:
- unstable angina (23%),
- myocardial infarction (31%),
- unheralded coronary death (40%),
- heart failure (40 %),
- cardiac arrest/sudden coronary death (37%),
- of an ischaemic stroke and of a transient ischaemic attack (16%)
- in peripheral arterial disease (32%) and
- of an abdominal aortic aneurysm (23%),
which is consistent with the well-known “sick quitter” hypothesis.
The scientists concluded from their analysis, that non-drinkers are at increased risk of coronary heart disease, cardiovascular disease, and all-cause mortality, even when former and occasional drinkers have been removed from the analysis.
Bell S, Daskalopoulou M, Rapsomaniki E, et al. Association between clinically recorded alcohol consumption and initial presentation of 12 cardiovascular diseases: population based cohort study using linked health records. BMJ. 2017 Mar 22;356:j909.
Mukamal K, Lazo M, Alcohol and cardiovascular disease, BMJ 2017, 356: j140 doi: 10.1136/bmjj.j1340
For more information about this article, read the scientific abstract here.