July 13, 2014
Reducing Alcohol Consumption May Be Important For Your Heart Health
Rebekah Eliason for redOrbit.com - Your Universe Online
These new findings contradict previous studies that suggest light-to-moderate consumption of alcohol, about 12-25 units per week, is beneficial for cardiovascular health.
For this study, a team led by the London School of Hygiene & Tropical Medicine with University College London and University of Pennsylvania examined evidence from 50 different studies to evaluate the drinking habits and cardiovascular health of more than 260,000 people. Researchers discovered that people who possess a genetic variant lowering their inclination to consume alcohol, on average, have a more positive cardiovascular profile. The authors suggest a reduction in alcohol consumption is beneficial for heart health.
Individuals with lower alcohol consumption averaged a ten percent lower risk of having coronary heart disease, lower blood pressure and a lower Body Mass Index.
Senior author Juan P. Casas, Professor of Epidemiology at the London School of Hygiene & Tropical Medicine, said: "While the damaging effects of heavy alcohol consumption on the heart are well-established, for the last few decades we've often heard reports of the potential health benefits of light-to-moderate drinking. However, we now have evidence that some of these studies suffer from limitations that may affect the validity of their findings. In our study, we saw a link between a reduced consumption of alcohol and improved cardiovascular health, regardless of whether the individual was a light, moderate or heavy drinker. Assuming the association is causal, it appears that even if you're a light drinker, reducing your alcohol consumption could be beneficial for your heart."
For this study, researchers picked out a gene that is an indicator of alcohol consumption. People who possess the genetic variant of the ‘alcohol dehydrogenase 1B’ are known to metabolize alcohol at a different pace. This rate of breakdown causes unpleasant symptoms that include nausea and facial flushing. Because of these symptoms people tend to lower their long term alcohol consumption. Using this genetic variant as a mark of lower alcohol consumption, the researchers were able to identify a link between these people and better cardiovascular health.
Studies about the long-term health effects of alcohol consumption are challenging because of the difficulty in finding individuals who will maintain a consistent level of alcohol consumption for an extended period of time. The authors say using a genetic approach is similar to the principals of randomized control trials and consequently reduces the limitations of previous observational studies.
Limitations are in part due to a bias from the effects of other healthy behaviors associated with people who moderate their alcohol consumption. This may explain why previous studies have observed a protective effect from alcohol, but it may not be alcohol itself that is protective.
In addition, previous studies are limited by the issue of distinguishing between self-reported non-drinkers, which may include people who have never consumed alcohol, and people who ceased alcohol consumption because of poor health.
Results from this current study strongly suggest that lower alcohol consumption is beneficial for heart health. This study is closer to establishing the correct causality than other observational studies. Although, additional replications of genetic studies using large scale prospective studies will be needed.
Dr. Shannon Amoils, Senior Research Advisor at the British Heart Foundation, said: "Studies into alcohol consumption are fraught with difficulty in part because they rely on people giving accurate accounts of their drinking habits. Here the researchers used a clever study design to get round this problem by including people who had a gene that predisposes them to drink less. The results reinforce the view that small to moderate amounts of alcohol may not be healthy for the heart although the study would need to be repeated in a larger group of people for definitive results. Whilst the heart health effects of light to moderate alcohol consumption are still unclear, what is clear is that drinking more than the recommended limits of alcohol can have a harmful effect on the heart."
This study was published in The BMJ.