One day, science shows that coffee is good for you, but the next day, science finds that coffee is bad for you. One day, chocolate is bad for you, and the next, it is good for you. Studies show that red meat is both good and bad for you. As we read the latest news, science seems to contradict itself every day. With all this confusion about science and nutrition how do we know which foods are good or bad for our health? A recent study has tried to simplify the answer for the link between alcohol and health.
One of the reasons for apparent contradictions in science is due to the nature of science. There is no answer sheet to check for the right answer and no textbook to see if your conclusion is correct. Science is completely new, and each study adds a small piece to our understanding of the world. Because each study is limited in what it investigates, occasionally the conclusions drawn from different studies may be at odds with one another. However, once enough science has been conducted, it is possible to “average out” all the information on a particular topic and come to a consensus. This consensus is often a “yes” or “no” answer to a single question, such as “Does chocolate lower blood pressure?” or “Does coffee increase the risk for cancer?” (Hint: the answers are yes, chocolate lowers blood pressure and no, coffee does not increase the risk for cancer!). One way to do this is by performing what is called a metanalysis.
Metanalyses investigate the research on a specific topic (such as a possible link between processed meats and cancer) and combine it to come to a single conclusion. A recent metanalysis studied the link between alcohol consumption and disease by combining information from 592 studies that investigated the risks and benefits of alcohol.
The most important finding from the study is that even a single standard drink of alcohol per day increases a person’s risk of health problems, such as cancer, stroke, injuries, and infections. Furthermore, two drinks per day lead to a 7% higher risk of dying from alcohol-related health problems, and five drinks per day lead to a 37% higher risk of dying. Because of the study’s design, it is unclear how long these drinking levels must be sustained to increase the risk for health problems; future research should study this question. Although the metanalysis found that moderate consumption of alcohol (1-3 standard drinks daily) reduces the risk of ischemic heart disease and diabetes moderate alcohol consumption still increases the risk of developing over twenty other health complications and diseases. This increased risk explains the finding in this study that alcohol is the 7th leading risk factor for deaths globally, with alcohol involved in 2.2% of female deaths and 6.8% of male deaths in 2016. The disparity in male vs. female deaths may be due to discrepancies in drinking rates, since in many areas of the world, men drink more alcohol than women.
This metanalysis emphasizes the importance of re-evaluating current public health recommendations. The U.S. Dietary Guidelines recommends no more than 1 drink per day for women and no more than 2 drinks per day for men, and it also suggests that people who do not drink should not start drinking. However, the metanalysis discussed above suggests that we should reconsider these guidelines and avoid recommending alcohol consumption to anyone. This recommendation is unlikely to be a popular opinion, due to the number of people who enjoy consuming alcohol on a regular basis as well as the alcoholic beverage companies who prefer to cite science showing that moderate drinking is healthy. However, the sheer number of deaths caused by alcohol consumption (2.8 million deaths globally in 2016) highlights the importance of a thorough review of alcohol recommendations. Until then, we should individually consider how much and how frequently we consume alcohol, since alcohol does not keep the doctor away.
Peer-edited by Priya Stepp