Alcohol use has a complicated association with health. It tends to follow a “U” shape curve. Some research suggests that low levels of alcohol consumption give some protection against heart disease, diabetes and several other conditions. Too much alcohol on the other hand, can lead to adverse effects on organs and tissues leading to injuries, poisoning, potential self-harm or violence. So there’s a “sweet” spot.
The Global Burden of Disease Study 2016 collected data from developed and developing nations, involving 195 countries and territories, from 1990-2016. It is one of the largest studies of its kind looking at the association between population-wide consumption of alcohol to population wide trends. This study published in the Lancet concluded that alcohol consumption is involved in 2.8 million deaths worldwide annually. This makes it the 7th leading risk factor for death and disability.
The bottom line in this study was that alcohol use (10 grams of pure ethyl alcohol = 3.4 ounces of red wine at 13% alcohol, 12 ounces of beer at 3.5% alcohol or 1 ounce of 80-proof whiskey) is a leading risk factor for global disease burden and causes substantial health loss and the level of consumption should be zero!
OK…so that doesn’t sit well with many of us. So lets look deeper in the study.
First of all, the researchers relied on sales of alcohol and surveys to estimate the prevalence of drinking in each country. They linked consumption data to 23 health outcomes which included car accidents, suicides, tuberculosis, liver cirrhosis, cardiovascular disease and cancers.
Rates of alcohol consumption vary greatly by country. Plus, this was a meta-analysis, which means it is a collection of many observational studies in which the data is then combined into mathematical models to predict the harm from alcohol consumption worldwide. The problem is, observational data can miss other causes of the problem. Examples are: Do those who drink have other health problems, such as smoking tobacco? Do those that drink alcohol have an unhealthy diet or live in poorer neighborhoods? These could be more of the cause of death and disability, and the studies that were analyzed did not look at these variables.
Second, looking at the health outcome of tuberculosis (TB) is interesting. According to the World Health Organization, over 95% of cases and deaths of TB are in developing countries and those that are infected with HIV are 20-30 times more likely to develop active TB. Again, this could be a confounding factor as I described above because the causes of death in developing countries are different than in developed nations. TB was the major cause of death in young adults, and we know alcohol can raise the risk for TB activation. This may show a statistical significant change in the data but gives an overall bias in the clinical importance.
Third, this is a world wide study, but the results are being interpreted at an individual level. The 23-alcohol related health issues are not experienced at the same rate. For instance, the rate of heart disease and diabetes actually go down with light or moderate drinking. The risks for cancer and tuberculosis can go up for some people (depending on many circumstances). It’s not clear that everyone is at the same risk in real life.
So if 0 drinks is ideal, what is the risk at 1 drink per day? Well, if you don’t drink, 914 for every 100,000 people can expect to experience one of the 23-alcohol related problems in any given year. Having 1 drink per day, that number goes to 918 per 100,000. That means 99,082 are unaffected. So the risks in the study present themselves as much bigger than they really are. Don’t get me wrong…I’m not advocating drinking, but there is a balance and we shouldn’t interpret these results individually to induce panic or fear to change policy. We have enough of that right now.
So we need better studies. More likely a large randomized control trial looking at light to moderate drinking, to get the best perspective on the harms and benefits of alcohol consumption. This may give us more answers on the way most people consume alcohol and perhaps give us insight on more specifics such as cultural, age and gender differences.