Monday, May 2, 2011

Health effects of binge drinking

In Canada, a "drink" or a "standard drink", as a unit of alcohol consumption, refers to a drink containing 13.6 grams of ethanol.  This amount is present in a 12-ounce (355 mL) beer, or a 5-ounce (146 mL) glass of wine, or a 1.5 ounce (44 mL) shot of hard liquor such as whiskey or vodka.  Reference: *

Binge drinking is defined as having 5 or more drinks on one occasion for men; or 4 or more drinks on one occasion for women.  This pattern of consuming alcohol is a common cultural habit, with historic roots going back thousands of years.

There are various sources of epidemiologic evidence that light drinking may have health benefits.  My review of the evidence suggests that the cut-off point for this would be no more than 2 drinks per 24 hours, with any episodes of greater alcohol consumption conferring a substantial health risk (both physical and psychiatric).

When it comes to binge drinking, I believe the health risks are very high.  The immediate risks have to do with accidents & injuries, which are much more likely during a binge drinking episode.  This risk also affects other people, such as passengers in a car or other drivers on the road.

In my opinion, the psychiatric risks of binge drinking can be divided into several categories:

1) Simple addiction.  If heavy intoxication is associated with pleasure or relief, this may easily become an addictive process, such that relief or pleasure may only come with intoxication.  As a result, other activities not involving intoxication become more subjectively boring and more prone to induce dysphoria rather than pleasure.   I call this the "greying of the sky" phenomenon.  The sky becomes less and less blue--figuratively speaking-- the more one repeats an addictive behaviour.  It is so gradual as to often be unnoticable, until years later one may have the realization that the simple pleasure of gazing at the blue sky is no longer available. 

2) Subcultural effect.  In conjunction with simple addiction, binge drinking is likely to affect one's social network, such that one's friends will more likely also be binge drinkers.  This makes it more difficult to leave the behaviour behind, since it would involve leaving one's social network.  Also the subcultural effect tends to cause a subjective normalization of the behaviour, such that people could actually feel abnormal if they cut back or stopped binge drinking.  Heavy drinking and its associated behaviour are a regular source of humour in our culture, which unfortunately may be another normalizing influence for those who are addicted. 

3) Direct pharmacological effects during intoxication and withdrawal.  Aside from the obvious effects during intoxication, I observe that binge drinking often leads to "mini-withdrawals" afterwards.  While many people may normalize their once-weekly alcohol binge, they may not realize that the withdrawal effects during the rest of the week cause impaired sleep quality and heightened anxiety.  Many young people are very resilient, so this may not be a problem, but if there is already a progressing problem with anxiety, depression, or other causes for insomnia, then binge drinking will make these problems much more difficult to treat.   I believe that the presence of binge-drinking behaviour makes antidepressant treatment much less likely to be successful.

My recommendation is never to binge drink.  More than 2 drinks per 24 hours is harmful, causing adverse short-term and long-term health effects in all cases.  If binge drinking is a significant part of recreational culture for any individual, then therapeutic work needs to be done not only to cut back on alcohol consumption, but to build a healthier cultural life, and probably a healthier social network.   

Here is a review of some of the research literature on the subject:
binge drinkers have double the rates of depression; reductions of drinking subsequently associated with reduced depressive symptoms.
This is a very strong 2010 prospective twin study, showing that binge drinkers have double the risk of cognitive impairment (dementia); light drinkers have the lowest risk; abstainers in the middle.   High alcohol intake is clearly a strong risk factor for dementia; binge drinking is a risk factor independent of total alcohol intake. That is, even if you don't drink a large volume of alcohol in a month, if you ever binge drink you will still be in a high risk group.
prospective study showing increased strokes and overall mortality in binge drinkers
Current binge drinking associated with increased depression 5 years later. This was strong data with a good effort to control for confounding factors. Heavy intoxications at least once a month, especially with associated phenomena (e.g. blackouts, hangovers), were associated with double to fourfold increases in hospitalizations due to depression.
binge drinking a stronger predictor of social harms (e.g. violence, loss of relationships) than total alcohol volume
2011, large epidemiologic study.  16% of men over 50 met criteria for binge drinking, 6% of women over 50.   Binge drinking behaviour strongly correlated with alcohol dependence (alcoholism).
another major prevalence study
a concise review from the Centers for Disease Control and Prevention.  Prevalence of binge drinking at least 20% for men, 10% for women; rates were higher still for young adults.
this study shows even higher binge drinking prevalences for college students; 40% of this population engaging in binge drinking in a one month period.
This is a very nice 2010 review article and discussion from JAMA , about the health impacts of alcohol consumption, particularly the question of whether light drinking might protect against cardiovascular disease.  In the particular case discussion, it is concluded that light drinking could have a small but insignificant positive health impact, and it would be more a lifestyle choice than one rationally motivated by health variables.  For other individuals, any drinking at all could confer substantial health risks (e.g. those with severe addictive disorders, high sensitivity to negative side-effects of alcohol, various medical diseases).  Reasonable warnings are included, such as never to drink while pregnant, before driving, etc.

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