There’s been a lot of press over the last several years about how alcohol might affect our health for the better. Several studies that have looked at large groups of people and found that a moderate amount of alcohol consumption (one drink for women, two for men) every day decreases the risk for coronary artery disease when compared to those who don’t drink anything at all or those who drink too much. But a new study out this week indicates there may be some nuance to that claim.
Scientists and doctors have been interested in how a person’s genetic makeup might influence different aspects of their health. As new tools have become available that allow researchers to sequence the genes of study participants for a reasonable price, it’s become possible to get a sense of exactly how genes might be influencing a person’s response to a specific treatment or how likely they are to get a disease.
Research has shown that different people respond to alcohol in different ways. This is because small changes in their genes affect the way their liver breaks down alcohol and what kind of chemicals end up in their blood as a result. For example, some individuals of Asian ancestry can develop skin flushing after drinking alcohol because their body lacks a certain enzyme to break down one alcohol byproduct. The researchers in this study wondered whether similar genetics may influence whether alcohol prevents heart disease.
More specifically, they tried to figure out how alcohol might be reducing heart disease rates. Several studies have found that antioxidants present in certain alcoholic drinks, like wine, may help protect the heart. But given the consistent association not just with wine, but with alcohol in general, they thought it may have something to do with how the body deals with cholesterol. One study done several years ago had found that a certain gene called CETP involved with cholesterol seemed to reduce the risk of heart disease when combined with alcohol.
The thing is, that same study found that only some people have the right version of the gene for this to happen. Those with the right version saw a reduction in their heart disease risk by almost 60%. Those without the helpful version saw no change in their risk for heart disease.
This new study looked at 3614 Swedish men and women aged 25-75 with a wide range of drinking habits from abstainers to heavier users. They looked to see what version of the CETP gene they had and then looked over time to see how many developed heart disease. By comparing the rates of heart disease in those with and without the gene based on how much alcohol they drank, they could figure out whether the gene played a role in determining alcohol protection.
They indeed found that low levels of alcohol were protective. Surprisingly, though, in those who had the right gene, even high levels of alcohol helped protect against heart disease. In those without the right version of the gene, alcohol consumption had little to no effect on cardiac risk and at times even slightly increased it. The researchers concluded that the overall drop in heart disease risk seen in the population as a whole was mostly due to the significant drop seen in those with the right version of the gene.
Unfortunately, only about 15% of people have the right gene combination. The rest of us don’t. What does that mean for you? Since there’s no test readily available to see if you’re one of the lucky few, you probably shouldn’t count on alcohol to stave off heart disease.