Thursday 19 January 2023

Canada's clown world drinking guidelines

Canada is on the brink of making itself an international laughing stock by cutting its drinking guidelines from two drinks a day to two drinks a week. The previous guidelines were only set in 2011 so Canadian drinkers can be forgiven for being suspicious about this dramatic change. The evidence base has not significantly changed in the interim. The evidence for the health benefits of moderate drinking has continued to pile up. 

The only thing that has really changed is that neo-temperance zealots like Tim Stockwell have tightened their grip on alcohol research. Stockwell and his 'no safe level' pal Tim Naimi both live in Canada and are both authors of the report that has made the ludicrous new recommendations.

I have been saying for over a decade that the 'public health' plan is to get the guidelines down to zero so they can start regulating alcohol like tobacco. The evidence does not support this fundamentally ideological campaign and so the evidence has been dropped in favour of fantasy modelling and cherry-picking.

There is a continuum of risk associated with weekly alcohol use where the risk of harm is:

  • 0 drinks per week — Not drinking has benefits, such as better health, and better sleep.
  • 2 standard drinks or less per week You are likely to avoid alcohol-related consequences for yourself or others at this level.
"Likely"!? How about certain
  • 3–6 standard drinks per week — Your risk of developing several types of cancer, including breast and colon cancer, increases at this level.
The only source given for the claim about colon cancer is this meta-analysis which claimed that 10 grams of alcohol per day was associated with a seven per cent increase in colon cancer risk. This is a smaller risk than having a portion of red meat a day. It found no statistically significant increase in risk in studies which had data on what happens when people have one 'drink' a day.

A Canadian 'standard drink' contains 13.45 grams of alcohol. Three standard drinks equals 40 grams. Four standard drinks equals 53 grams. The meta-analysis has no data on people who drink so little, so the claim that colon cancer risk increases at three or more standard drinks is not supported even by the authors' own preferred source.

As for breast cancer, which can only affect half the population and is partly why most countries have different guidelines for men and women, the report cites this meta-analysis of 22 studies, 13 of which found no statistically significant association with drinking. It pooled the studies and reported a 10 per cent increase in risk for people drinking 10 grams of alcohol a day. As with the colon cancer study, this was the minimum quantity studied so it tells us nothing about Canadians who drink 3-5 standard drinks.

In terms of mortality, another meta-analysis found that light drinking was not positively associated with any form of cancer, including breast cancer, and was negatively associated with cancer in a couple of instances:

.. light drinking reduced the mortality of female stomach cancer (RR, 0.65; 95% CI, 0.44 to 0.98; n=1) and male lung cancer (RR, 0.79; 95% CI, 0.70 to 0.87; I2=0.0%; n=5). There was no significant association between light drinking and the mortality of oropharyngeal cancer, esophageal cancer, larynx cancer, colorectal cancer, liver cancer, female gallbladder cancer, pancreatic cancer, breast cancer, cervical cancer, prostate cancer, and hematologic malignancy.
As with all this evidence, we should remember that people under-report the amount of alcohol they consume by around 50 per cent, so when a study says 10 grams a day it probably refers to 20 grams a day. This is an important point that anti-alcohol researchers are well aware of but only mention when it suits them.
  • 7 standard drinks or more per week — Your risk of heart disease or stroke increases significantly at this level.
This is just a flat out lie. As countless studies have shown, heart disease and stroke risk is substantially reduced among light and moderate drinkers. For example, a meta-analysis of prospective cohort studies (which track people’s drinking habits and health status over a number of years and are the most reliable studies in observational epidemiology) found that drinkers were 25 per cent less likely to die from coronary heart disease than teetotallers. The evidence for strokes is similar.
This is main reason why life expectancy is longer for moderate drinkers and the relationship between alcohol consumption and mortality is J-shaped.

The authors of the Canadian report essentially ignore all this evidence and instead focus on a cherry-picked meta-analysis written by Stockwell, Naimi and pals which massively adjusted the figures to arrive at their desired conclusion. This is inexcusable.
  • Each additional standard drink radically increases the risk of alcohol-related consequences.
"Radically"! Be careful out there!
The whole thing's a joke and I suspect the public will see it as such. There is a legitimate debate about whether low levels of alcohol consumption slightly increase cancer risk, but this has to put within the context of the reduction in risk for cardiovascular disease. The fact remains that the positive effects of moderate drinking on heart disease and other conditions exceed and outweigh the negative effects on cancer risk
People want to know what the overall risks of light, moderate and heavy alcohol consumption are. This is what drinking guidelines should tell us. Focusing on small and unproven cancer risks at very low levels of consumption while ignoring the benefits is lying by omission. 

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