Diet Debates: Is moderate alcohol consumption good for health? (Part 1)

One of the questions I get asked the most frequently is whether alcohol consumption is compatible with healthy living, and if so, what types are best, and how much is acceptable? Is red wine the ultimate tipple, or can can grain based fermented beverages (aka beer) play a role?

Although alcohol is often demonised within the health and fitness community, and undoubtedly chronic alcohol consumption and binge drinking will ruin your health and your physique, there are also those who claim that moderate alcohol consumption will not only do you no harm, but could in fact be good for you.

(I did have a link here to various studies, but it appears to have broken!)

The evidence in favour of moderate alcohol consumption seems pretty compelling!  That’s a lot of studies, covering a lot of people – Surely conclusive proof that we should all be consuming 1-2 drinks per day?

One quote I found of particular interest was from the Danish National Institute of Public Health which found:

Cardiac disease is a major cause of death and aerobic exercise can also reduce the risk of such death, but it can’t serve as a substitute for the moderate consumption of alcohol.

Regular exercise can’t substitute for the moderate consumption of alcohol? Should we be spending less time in the gym, more in the pub?

The problem with all of these studies, however, is that they are observational in nature. That is, rather than being a controlled study with independently tested variables, scientists simply look for population trends. While this can raise some interesting questions, one must always bear in mind that correlation does not imply causation.

All scientists should know this, but unfortunately, due to a mixture of human nature, corporate sponsorship, and sloppy (or biased) media reporting, this message does not get passed onto the public, and instead we get messages along the lines of “[Insert product here] prevents [Insert disease here]”.

Despite their limitations however, these kind of studies can be very useful. For instance, scientist noted that people that smoked tended to have much higher rates of lung cancer, as did people that were regularly exposed to asbestos. Further investigation found the mechanisms by which both these toxins caused the damage, and as a result innumerable premature deaths have been prevented.

On the flip side of the coin, however, there are so many confounding factors involved in human behaviours, it is easy to be led astray. A good example of this is Ancel Keys 7 countries study – By plotting the data of 7 countries’ saturated fat consumption and rates of heart disease on a graph, Keys concluded that increased fat intake = increased heart disease, and thus was born the Lipid Hypothesis. Unfortunately Keys didn’t take into account confounding factors – I.e. if you look at the same countries and plot TV ownership, car ownership or sugar consumption against heart disease rates, you get pretty much the same trend line!

Another example of results being distorted can be found in one of the above alcohol studies. The positive association between alcohol consumption and longevity found in the Frammington Study were initially suppressed by the government, and people were told to decrease their consumption regardless. This was the same study that found no correlation between saturated fat consumption and mortality risk, and yet the government still advised the population to follow a low fat diet! Another fine example of evidence being ignored when it doesn’t fit a pre-formed hypothesis.

This potential for distortion and misinterpretation makes me dubious whenever I see any kind of epidemiological data being reported as scientific fact (or any kind of study for that matter). I accept that moderate drinkers generally live longer than teetotallers, but is this necessarily down to any protective properties of booze itself, or just down to the fact that people that don’t drink at all are doing something else that is inherently dangerous?

Scientists have proposed a number of possible mechanisms by which drinking can protect health – Reservatol in red wine, blood thinning effects of alcohol itself etc, but none have actually been proven. Also, a number of studies, found that drinking 2-4 alcoholic beverages per day reduced risk of death from ALL CAUSES. This presumably included getting run over, choking and being savaged by bears – Show me a mechanism for how alcohol helps there!

Another spanner in the works for the alcohol prolongs life theory is that one of the, the 7th Day Adventists in California, a group renowned for an unusually high proportion of centenarians, are teetotal.*

Is it possible, that rather than being due to any magical property of alcohol, the life extending properties come from the social aspects of drinking? Are those people having a glass of wine each evening doing so with their loving partner (being in a relationship also shown to increase longevity), or those having a few beers a week doing so with their mates down at the pub (again, having a good social network of true friends also associated with longer life expectancy), whereas the teetotallers are sat alone, depressed at home, eating cake?

So the conclusion of my extensive research scouring studies covering over 100 000 people over numerous continents? Still none the wiser! People live to 100 eating vegetarian diets (not vegan – dairy and eggs supply the essential nutrients) and abstaining from alcohol altogether, while others can drink everyday and eat burgers and still get their letter from the Queen. Despite their best efforts to pin down the secret of eternal youth, the scientists have still to find the secret.

Human life is so complex, with so many interacting factors – Genetics, environment, diet, lifestyle, social/psychosomatic – It is pretty much impossible to isolate the effects of one factor (unless as with the case of smoking and asbestos it has a significant negative impact).

That said, as moderate alcohol consumption clearly doesn’t have any negative effects on your life expectancy or health, and may even be beneficial, so it appears there is no compelling reason why its regular consumption should not be compatible with a healthy lifestyle.

In my next post I’m going to look at the effects of alcohol consumption on body composition, athletic performance, and whether there is any benefit to choosing one type of alcohol over another.

In the meantime, bottoms up!

*Thanks to Ivor in the comments for the correction on the Okinawans