Alcohol consumption and health

The controversy over moderate drinking is an ongoing debate about the claimed benefit or harm to human health from moderate consumption of alcoholic beverages. Moderate consumption typically means the consumption of 1 to 3 drinks of an alcoholic beverage a day; the number varies with age and gender. There is wide consensus that over-drinking is harmful: alcohol damages human cells and organs such as the brain, liver and kidneys, and it weakens the immune system.

Many studies show that consumption of up to 3 drinks a day have a 10% to 40% lower risk of coronary heart disease than those who abstain. Rimm et al predict a 24.7% decrease in the risk of coronary heart disease based upon 30g alcohol/day. (Rimm et al, 1999). An individual consuming 30g alcohol/day increase in high density lipoprotein cholesterol ("good" cholesterol") concentration of 3.99 mg/dl compared to an individual who abstains, an increase of 8.3%. The effect is higher in people with lower initial HDL levels. Apolipoprotein A I had a 6.5% increase. However, triglyceride concentrations increased by about 5.9%.

Critics of moderate drinking claim that any benefits are far outweighed by the harms and that these benefits can be had by less risky means. Scientists also note that studies supporting the benefits of moderate drinking do not control for other factors, such as lifestyle differences between moderate drinkers and nondrinkers. There is evidence that moderate drinkers are more affluent than nondrinkers and as such lead lifestyles that are more conducive to good health in general.

Research on the effects of moderate drinking is in its early stages. No long term studies have been done and control groups would be difficult to establish because of the many variables. Given the current state of the research, an editorial concludes in the December 1997 issue of the Journal of the Royal Society of Medicine that the recommendation to be a moderate drinker is "not only meaningless but also irresponsible" given that the many obvious health hazards of alcohol outweigh "the benefits of alcohol [which] are small and ill-understood" particularly when so many other cardiovascular treatments are available.

The U.S. Department of Health & Human Services’ National Toxicology Program listed alcohol as a known carcinogen in 2000. The NTP profile report on alcohol states that incidences of cancer rise dramatically when alcohol is used in conjunction with tobacco, another known carcinogen.

However, it is inevitable that humans intake some moderate amount of alcohol, even if they never drink in their lives. This is because many of the bacteria in our intestines use alcohol fermentation as a form of respiration. This metabolic method produces alcohol as a waste product, in the same way that our metabolism results in the formation of carbon dioxide and water. Thus, we always intake some quantity of alcohol, which is produced by these benign bacteria. In fact, if we eat enough carbohydrates (a few pieces of bread, for instance), the alcohol levels in our bowels can soar to the equivalent of a few ounces of wine, some quantity of which will inevitably be absorbed by the intestinal wall, and thus circulated throughout our bloodstream. In nature, the quantity of alcohol necessary to prevent heart disease is mostly produced by these microorganisms, but in the modern world, humans tend to consume far larger quantities of fat and cholesterol than they did in Paleolithic times. Therefore it might be necessary to intake a moderate quantity of alcohol to maintain homeostasis long into your adult life.

References

• Moderate alcohol intake and lower risk of coronary heart disease: meta-analysis of effects on lipids and haemostatic factors (http://bmj.bmjjournals.com/cgi/content/full/319/7224/1523?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&author1=rimm&searchid=1025569638239_15875&stored_search=&FIRSTINDEX=0&resourcetype=1,2,3,4,10). BMJ (British Medical Journal) 319:1523-1528.

• National Toxicology Program's profile report on alcohol (http://ehp.niehs.nih.gov/roc/tenth/profiles/s007alco.pdf)

• CDC Study Skeptical on Moderate Drinking's Heart Benefit (http://www.medpagetoday.com/tbindex.cfm?tbid=912)