I am fairly certain that most of the feathered dinosaur’s readers have read articles about alcohol health effects. It’s bad. It’s good. It prevents heart attacks. It causes cancer. It reduces risks of Sasquatch attacks but increases risks of alien abductions.
I know some of you are thinking that science never gets this right. Who are you to believe? An ancient feathered dinosaur? Your favorite news website? Your next door neighbor? Alien Sasquatch?
Well, there was a recent article published that employed a powerful systematic analysis of the body of published evidence surrounding alcohol health effects. Spoiler alert – drinking any amount may not be good for your health.
Alcohol health effects – the paper
The study, published in the respected medical journal The Lancet and authored by the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) group, examined the global burden of alcohol health effects for 195 countries and territories from 1990-2016. It is considered the most comprehensive estimate of the global burden of alcohol use to date.
The study employed a systematic analysis (see Note 1) of 694 data sources of individual and population-level alcohol consumption. It also included 592 prospective and retrospective epidemiological studies on the risks of alcohol use. The researchers produced estimates of the prevalence of drinking and abstention along with the distribution of alcohol consumption among current drinkers. The authors standardized the number of drinks daily as 10 g of pure ethyl alcohol equivalent to one drink.
The authors used an improved methodology to improve results compared to previously published estimates:
- They adjusted alcohol sales estimates to include tourist and unrecorded consumption;
- They performed a new meta-analysis of relative risks for 23 health outcomes associated with alcohol use;
- They developed a new statistical methodology to quantify alcohol health effects.
Those 23 health outcomes that the study examined were:
- Cardiovascular diseases: atrial fibrillation and flutter, hemorrhagic stroke, ischemic stroke, hypertensive heart disease, ischemic heart disease, and alcoholic cardiomyopathy;
- Cancers: breast, colorectal, liver, esophageal, larynx, lip and oral cavity, and nasal;
- Other non-communicable diseases: cirrhosis of the liver due to alcohol use, diabetes, epilepsy, pancreatitis, and alcohol use disorders;
- Communicable diseases: lower respiratory infections and tuberculosis;
- Intentional injuries: interpersonal violence and self-harm;
- Unintentional injuries: exposure to mechanical forces; poisonings; fire, heat, and hot substances; drowning; and other unintentional injuries; and
- Transportation-related injuries.
Alcohol health effects – the results
Overall, the study showed that, in 2016, nearly 3 million deaths globally were attributed to alcohol use. The risk of mortality far outweighed any potential benefits of alcohol use. Furthermore, the study showed that alcohol was linked to 12% of deaths in males between the ages of 15 and 49.
The study also showed that alcohol use was the seventh leading risk factor for deaths across the world. It accounted for 2.2% of all female deaths and 6.8% of all male deaths. But it gets worse than that – among individuals aged 15-49 years, alcohol is linked to 3.8% of female deaths and 12.2% of male deaths.
The study found that the main causes of alcohol-related deaths in the 15-to-49 age group were tuberculosis, road injuries, and suicide. For those older than 50, the leading alcohol-related cause of death was cancer.
In fact, the World Health Organization (WHO) lists a small number of factors that actually increase the risk of cancer. What do they say about alcohol?
There is no doubt that drinking alcohol can cause at least seven types of cancer: those of the mouth, gullet (oesophagus), throat (pharynx and larynx), liver, large bowel (colon and rectum), and breast.
Consumption of any amount of alcohol increases your cancer risk. The more alcohol you drink, the higher the risk of developing cancer. Reducing your consumption or – even better – avoiding alcohol completely will help reduce your cancer risk.
In other words, WHO has long suggested that no alcohol reduces your risks of several cancers.
Interestingly, eight of the top 10 countries with lowest death rates attributable to alcohol use among 15- to 49-year-olds were in the Middle East: Kuwait, Iran, Palestine, Libya, Saudi Arabia, Yemen, Jordan, and Syria. All of these countries are majority Muslim, which generally bans the use of alcohol. There is irony there. Conversely, seven of the top 10 countries with highest death rates were in the Baltic, Eastern European, or Central Asian regions, specifically Russia, Ukraine, Lithuania, Belarus, Mongolia, Latvia, and Kazakhstan.
Another key point is that the researchers found that no amount of alcohol provided any health benefit, evidence that supersedes what has been claimed in previous years.
This research is data heavy with two huge supplementary indexes – I have read probably a thousand, maybe more, systematic reviews in my long life and this one has to be in the top 10 of quality and quantity of data. I could spend a year pouring through the data to find interesting points or errors. But I’m going to default to the researcher’s analysis and repeat their conclusion:
Alcohol use is a leading risk factor for disease burden worldwide, accounting for nearly 10% of global deaths among populations aged 15–49 years, and poses dire ramifications for future population health in the absence of policy action today. The widely held view of the health benefits of alcohol needs revising, particularly as improved methods and analyses continue to show how much alcohol use contributes to global death and disability. Our results show that the safest level of drinking is none. This level is in conflict with most health guidelines, which espouse health benefits associated with consuming up to two drinks per day. Alcohol use contributes to health loss from many causes and exacts its toll across the lifespan, particularly among men. Policies that focus on reducing population-level consumption will be most effective in reducing the health loss from alcohol use.
Additionally, according to the Dr. Emmanuela Gakidou of the Institute for Health Metrics and Evaluation at the University of Washington School of Medicine, the senior author of this study, stated this about alcohol health effects:
The health risks associated with alcohol are massive. Our findings are consistent with other recent research, which found clear and convincing correlations between drinking and premature death, cancer, and cardiovascular problems. Zero alcohol consumption minimizes the overall risk of health loss.
With the largest collected evidence base to date, our study makes the relationship between health and alcohol clear – drinking causes substantial health loss, in myriad ways, all over the world.
And in an accompanying editorial in The Lancet, the authors supported the conclusions of the study:
The conclusions of the study are clear and unambiguous: alcohol is a colossal global health issue and small reductions in health-related harms at low levels of alcohol intake are outweighed by the increased risk of other health-related harms, including cancer. There is strong support here for the guideline published by the Chief Medical Officer of the UK who found that there is “no safe level of alcohol consumption”. The findings have further ramifications for public health policy, and suggest that policies that operate by decreasing population-level consumption should be prioritised.
Alcohol health effects – criticizing the study
Other than Big Alcohol, who have tried to push the myth that a little alcohol had no harm (or even benefits) to “prove” they are socially responsible, this study shouldn’t surprise anyone. That being said, I do have a couple of criticisms.
First, even though this was a powerful and robust systematic review (once again, the pinnacle of the hierarchy of biomedical research) that included millions of data points, it has one fundamental weakness – it is an observational, epidemiological study at its core. I’m much less concerned about these type of studies, because of a systematic review/meta-analysis, if done correctly, adjusts for bias and poor quality data. And again, the huge size of this study makes it more powerful.
Second, many people criticize these type of studies as incapable of establishing a causal link between alcohol use and healthcare outcomes. This is a valid criticism; however, there are reasonable logical methods that can be employed to establish causality from correlation. And this study did provide many of them – for example, there are mountains of data that establish a plausible link between alcohol use and motor vehicle fatalities.
The size and breadth of this study give it much more power than your one-off clinical or epidemiological study on alcohol health effects.
Summary
This was a strong systematic review that adjusted for a lot of confounding variables, and it showed a very strong correlation between any alcohol use and mortality. The authors showed over 3 million deaths globally linked to any alcohol use.
Moreover, it establishes that the risks of mortality from alcohol drinking overwhelm any potential benefits, real or mythical.
I know I’ll hear the claims that “science told us that moderate alcohol use” prevents this or that medical condition. The problem with those studies is that they were much smaller. And they were overhyped by the lay press (as this study was too).
Regardless of this study, I have long avoided alcohol because of the known, well-established link between alcohol use and risk of all cancers. This huge study convinces me more of the negative alcohol health effects.
Notes
- A systematic review is considered the most important form of scientific evidence utilized by science-based medicine. It is a form of research that performs a critical assessment and evaluation of all research studies that address the effect of pharmaceuticals, devices, standards of care, and other issues related to a particular clinical condition. A researcher who produces systematic reviews uses an organized method of collecting and analyzing a body of literature on a particular topic using a set of specific criteria. As evidence goes, a systematic review (or the more statistical meta-analysis) is generally considered to be the most powerful evidence in medical research.
Citations
- GBD 2016 Alcohol Collaborators.. Alcohol use and burden for 195 countries and territories, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet. 2018 Aug 23. pii: S0140-6736(18)31310-2. doi: 10.1016/S0140-6736(18)31310-2. [Epub ahead of print] PubMed PMID: 30146330.
- Burton R, Sheron N. No level of alcohol consumption improves health. Lancet. 2018 Aug 23. pii: S0140-6736(18)31571-X. doi: 10.1016/S0140-6736(18)31571-X. [Epub ahead of print] PubMed PMID: 30146328.
- de Menezes RF, Bergmann A, Thuler LC. Alcohol consumption and risk of cancer: a systematic literature review. Asian Pac J Cancer Prev. 2013;14(9):4965-72. Review. PubMed PMID: 24175760.
