Just 2 drinks a week... Really??

A look at Canada's new Low Risk Alcohol Guidelines...

So, have you been reading about the new Canadian Low Risk Drinking Guidelines too? The Canadian Centre on Substance Use and Addiction (CCSA) is telling us that any more than 2 drinks a week increases our risk of various diseases, with an emphasis on cancer – the disease many of us fear most – and that risk “increases radically” for each drink that is added beyond 7 drinks a week. This is quite a change from the previous guidelines that determined 1 to 2 drinks a day were low risk and up to 3 per occasion was considered moderate consumption, similar to guidelines in many other countries.

I must admit, having been bombarded with articles in the medical news since last November, I've felt guilty any time I've enjoyed a glass of red with a meal. But, something didn't quite sit right. I've learned that the cause of cancer is known to be “multifactorial” -- in other words, it's generally accepted that it is a combination of factors that add up to cause cancer in most cases, and some of these causes are likely still unidentified, so why such strict limits? Shouldn't we be looking at the overall picture more with a multifactorial disease?

For me, since I enjoy both the taste and the social side of moderate alcohol consumption, it's important to separate and balance the cancer risk from alcohol from risk caused by other factors. And it would be useful to know how great a difference in risk there is between following the new Canadian guidelines and sticking with the old ones that are still followed in most other countries.

Once in a while researchers do identify one important cancer risk factor, as with lung cancer, where smoking stood out as a significant cause. But what about cancer in non-smokers? New research has identified that inhaling small particles (known as PM2.5, indicating Particulate Matter smaller than 2.5 microns in size) regardless of particle origin may be a major culprit. Cigarette smoke contains many chemicals, several of which are associated with cancer risk, but it also contains tiny the particulate matter that's been identified as cancer-causing in non-smokers from various sources like dust and car exhoust, and other forms of smoke like cooking fires.. With cancer, it's not simple... the cause(s) are too often not obvious, perhaps because it may require a poor immune response along with the cancer-causing agent to result in the disease. We've all heard of that person who smoked heavily until their death from natural causes at an elderly age!

So, having a risk factor for a particular type of cancer, like having inherited the breast cancer gene, doesn't necessarily mean you will get the cancer. New research is examining how epigenetics, that control which genes are used (or “expressed”) are important in determining whether a person will get cancer or not.

Diet (avoiding processed foods), lifestyle (getting enough exercise, maintaining a healthy weight, and others), environmental exposures (avoiding pollution, toxins, and hormonally-active substances in the environment) and more are among the known causes of various cancers.

For breast cancer, just being a woman and being older are the two greatest risk factors, accounting for 70% of cases, according to one breast cancer information website. Genetics (inheriting a breast cancer gene) accounts for only 10% of cancers. Studies (not included in the references used to create the new Canadian guidelines) have found that the increased risk from moderate alcohol consumption of 4 to 6% translate into a small increase in actual risk numbers, and much less than the increased risk caused by poor diet or being overweight (see Harvard Health reference below).

As for cancer risks for alcohol, it's well-known that heavy alcohol use is a major factor in the development of liver cancer. But the statistics within the report itself suggest that it's a major risk factor in many diseases, including cardiovascular disease, although their chart indicates that up to 7 drinks per week actually lowers this risk (not mentioned in the recommendations). Among the criticisms of Canada's new guidelines is that they use scary statistics for diseases like tuberculosis, citing a doubling of the risk of this disease without mentioning that it's extremely rare. Doubling a risk of 2 cases per million people to 4 per million is a 100% risk increase, but the risk is still extremely low. The new guidelines have been criticized for manipulating statistics to make them appear more frightening.

One thing to be aware of, in any study (and I've seen this technique used all too often in drug studies sponsored by pharmaceutical companies), is to use “relative” numbers or ratios rather than “absolute” ones. Absolute numbers tell you exactly how much a measurement has changed, while relative ratios calculate the percentage of the change without telling you how big that number really is. This can make a very small actual number appear to be much more significant. In the esophageal cancer example in the last paragraph, the relative difference was 100% (sounds really scary), while the actual “absolute” number was only 2 per million or 0.0002% absolute risk increase (much less impressive, right?)

So, as soon as you realize these techniques are being used, you start to wonder what biases the writers of the report are hiding. Dan Malleck, a professor and specialist in alcohol regulation at Brock University in Ontario, points out this and other flaws in Canada's new guidelines.

One he mentions is that, although they claim to have consulted 6000 studies on the harms of alcohol, they set up vague “exclusion parameters” that eliminated all but 16 studies, leaving a very narrow range of information on which they based their guidelines (and hiding the fact that they only used a few studies for their guidelines). Their document was also not peer reviewed... in other words they didn't bother having other experts review their work before publishing (although apparently they did post it somewhere on the internet as a form of “consultation”).

Dan Malleck also points out that much of the language of the report is “inflammatory”, designed to create fear in readers, and that well-known benefits of alcohol were ignored, including only harms caused by alcohol (including violence and increased risk of accidents caused by alcohol intoxication from heavy drinking). Drinking to intoxication is one thing (known to be harmful on so many levels), while enjoying a pre-dinner cocktail or a nice glass of wine with a meal is another, in my opinion. It seems that all the harms were thrown into the pot when creating these guidelines, while the possibility of improved mental health, relaxation and beneficial socializing associated with alcohol use was left out of the calculation... not to mention the reduced risk of cardiovascular disease well-documented since many years ago in the Interheart Study and others from eating fruits and vegetables, exercising and consuming 3 or more alcoholic drinks per week.

So, I think the bottom line of “everything in moderation” is still the best advice. Each person should evaluate their personal level of risk versus potential benefit considering a wide range of health strategies (diet and lifestyle, as well as alcohol intake) and take action accordingly. Unless you are concerned about a single disease for some reason, I believe it's best to focus on an overall healthy lifestyle that you can enjoy, and consider mental as well as physical health (both are important!)

It's unfortunate that the new Canadian Low Risk Alcohol Guidelines document is not more open, balanced and inclusive, accounting for benefits as well as risks of alcohol and explaining the risks in a clear unbiased manner. Instead, it appears to advocate for abstinence (despite stating otherwise!), suggesting any alcohol consumption is risky with no possible benefits. They even went beyond their mandate of creating a guideline document and included advice for government to add health warning labels to all alcohol bottles based on their document.

PS: Image above is of drinks called "Sex on the Beach" and "White Russian", taken by the author in España! (we had some laughs about those silly drink names, and especially that we'd ordered them together!)

PPS: It seems we're much better about controlling our drinking than we used to be... Here's an interesting history of alcohol use in the Canadian Maritime Provinces (where I live!) if you're interested: https://backyardhistory.ca/f/drinking-in-the-maritimes?blogcategory=Moncton

References:

Canada's Guidance on Alcohol and Health – Canadian Centre on Substance Use and Addiction (CCSA)

UK Low Risk Drinking Guidelines -- Drinkaware

Study suggests scant increase in breast cancer risk from alcohol intake -- Harvard Health

Alcohol Guidelines Misleading – Dan Malleck (specialist in alcohol regulation), The Hamilton Spectator

What are the main causes of breast cancer? -- KnowBreastCancer.org

Is it safe to have an alcoholic drink before dinner? -- Dr. W. Gifford-Jones, The Kelowna Daily Courier

LinkedIn post, Dan Malleck

Interheart Study-- Medscape

Inhalable Particulate Matter and Health (PM2.5 and PM10) -- California Air Resources Board