American Cancer Society (ACS) just published their newly revised diet/exercise/etc guidelines on minimizing cancer risks. From a summary in Forbes:
The full recommendation is published as an article in a medical journal. An edited excerpt:Previous guideline from 2012: If you drink alcoholic beverages, limit to no more than 1 drink per day for women and 2 per day for men.
New: The ACS now says it’s best to completely avoid all alcohol. However, they say for people who do choose to drink. they repeat the previous recommendation of no more than 1 drink per day for women and 2 drinks per day for men.
It appears that the change in guideline from 1/2 drinks per day to 0 drinks is based on a study from 2016 performed by the Institute for Health Metrics and Evaluation (IHME), a global health research center at the University of Washington (US). IHME is in the business of evidence-based healthcare, they're funded in large part by Bill and Melinda Gates Foundation. Evidence-based healthcare is making conclusions based on data. Collecting massive amounts of data, untangling it, removing or factoring for bias, dealing with various other data issues is the nature of their work. They don't perform experiments of, say, making people imbibe various amounts of alcohol and then tracking their health.Alcohol consumption is the third major modifiable cancer risk factor after tobacco use and excess body weight.
In 2016, approximately 50.7% of the US population aged ≥12 years reported current (ie, in the past 30 days) alcohol consumption, approximately 6% were heavy alcohol drinkers (ie, drank ≥5 alcoholic beverages on the same occasion on ≥5 days in the past 30 days), and approximately 24.2% of the population were binge drinkers (ie, drank at least ≥5 alcoholic beverages on the same occasion on at least 1 day in the past 30 days).
Despite the fact that a substantial number of cancer cases are attributed to alcohol consumption in the United States, and that reducing alcoholic beverage consumption is one of the WHO Best Buys for reducing noncommunicable diseases, public awareness about the carcinogenicity of alcohol, and its primary metabolite acetaldehyde, is low. Furthermore, fewer than one‐half of the CDC‐funded comprehensive cancer control plans specify goals, objectives, or strategies for alcohol control. Finally, alcohol control has benefits beyond those for cancer, and recently a report from the Global Burden of Disease Study found that “consuming zero standard drinks daily minimizes the overall risk to health"
The study looked at alcohol use in 195 countries and territories for the period of 1990–2016. They went through a large spectrum of humans, ranging in age from 15 to 95+. That is a lot of data and at truly global scale but it's also a lot of factors. Common sense would dictate that someone who drinks copious amounts at 20 years of age is more likely to die from a road accident rather than cancer. The full text of the study confirms this. The older folks have a different story:
This conclusive last sentence has a very curious wording, "minimized harm across health outcomes". Remember all that stuff you've heard about how a glass of red a day helps you lower the risk of heart disease, wouldn't that be "minimizing harm"? They took that into account:For populations aged 50 years and older, cancers accounted for a large proportion of total alcohol-attributable deaths in 2016, constituting 27.1% of total alcohol-attributable female deaths and 18.9% of male deaths. The level of alcohol consumption that minimized harm across health outcomes was zero standard drinks per week.
Wait, what? Are they now saying that for a (presumably older) group where diabetes+heart disease are causing more deaths versus the rest of the population, it might help to drink more than zero glasses per day?! Their choice of words is almost deliberately oblique. Let's have a look at their graph that shows risk versus number of drinks:In estimating the weighted relative risk curve, we found that consuming zero standard drinks daily minimized the overall risk of all health loss The risk rose monotonically with increasing amounts of daily drinking. This weighted relative risk curve took into account the protective effects of alcohol use associated with ischemic heart disease and diabetes in females. However, these protective effects were offset by the risks associated with cancers, which increased monotonically with consumption. In a sensitivity analysis, where we explored how the weighted relative risk curve changed on the basis of the choice of weights for various health outcomes, the curve changed significantly only in settings where diabetes and ischemic heart disease comprised more than 60% of total deaths in a population.
Color me purple and call me Barney, 0 drinks and 1 drink appear to yield the same risk! If you think this is an optical illusion, have a look at the hi-res version of the graph. Without diving into their data, I can't say if the 0 versus 1 line is truly straight and the risk is indeed the same...but it certainly looks that way. Someone call Forbes.
Last but not least, ACS and IHME study appear to be using a different definition of a "standard" drink.
IHME: Standard drink is 10 grams of pure alcohol. About the equivalent of:
A small glass of red wine (100 ml or 3.4 fluid ounces) at 13% alcohol by volume;
A can or bottle of beer (375 ml or 12 fluid ounces) at 3.5% alcohol by volume; or
A shot of whiskey or other spirits (30 ml or 1.0 fluid ounces) at 40% alcohol by volume.
“Standard drinks” are different by country. For example, in the UK a standard drink is 8 grams of alcohol, whereas in Australia, the US, and Japan, it is 10 grams.
ACS: Standard drink is 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of 80-proof distilled spirits. 5 ounces of wine at 12-13% is 14 grams of pure alcohol.