Of Mice and Binges
Folk wisdom (read collective observational experience) for millennia and epidemiological study stimulated by the French paradox for decades have accumulated ever-increasing support for the J-shaped curve of drinking and health: moderate drinking enhances health and longevity; abstinence seems an adverse health risk; and heavy drinking is a danger to health and life. Within these broad strokes, however, devilish details demand delineation. Among intriguing, important and intricate questions raised are those concerned with patterns of drinking, individual (likely genetically determined) responses to drinking, what beverages are consumed and other confounding factors.
We have seen suggestive evidence that our patterns of drinking may matter as much as quantity. One generally accepted admonition holds that binge drinking is particularly dangerous. Do not save up your week’s allotment for Saturday night! Alcohol is generally believed healthiest when taken regularly, especially with meals. As I write this piece, awaiting publication is a well done and informative study that, as a member of the International Scientific Forum on Alcohol Research, I’ve had the opportunity to review. I believe it is well worth sharing with you. The Forum would agree. From the University of Rochester Medical Center, Weimin Liu, Eileen M. Redmond, David Morrow, and John P. Cullen’s paper, “Differential Effects Of Daily-Moderate Versus Weekend-Binge Alcohol Consumption On Atherosclerotic Plaque Development In Mice” [Atherosclerosis (2O1O), doi:1O.1O16/j.atherosclerosis.2O11.O8.O34], reports, in almost too-good-to-be-true crisp and clear-cut terms, results confirming our beliefs that regular moderate drinking is healthful, and that binge drinking, even of the same quantity, is damaging. I believe this is the first controlled experiment to demonstrate these differential effects.
Before spying on the partying mice, let’s pause to briefly review some of the essential medical background of moderate drinking’s beneficial effects upon health. Cardiovascular disease, chiefly in the form of atherosclerosis (largely heart attacks and strokes), a degenerative and inflammatory disorder of the inner lining of arteries, is by far the most common cause of disability and death of men and women in the developed world. Drinking’s most important and best studied health benefit is reduction in atherosclerosis. Many studies, for example, have found decreases of deaths due to heart attacks, as well as of overall mortality, of up to 4O percent in moderate drinkers compared to abstainers. Alcohol is credited with well over half the salubrious rewards. The polyphenols of wine, particularly red wine, have been tentatively honored for the rest. The mechanisms involved are complex and not yet fully understood. It is known, though, that alcohol induces an increase in the heart-healthful high-density lipoprotein cholesterol (HDL-C), the “good cholesterol”, and may reduce heart-damaging low-density lipoprotein cholesterol (LDL-C), the “bad cholesterol”. The former protects the heart and arteries; the latter renders them prey to atherosclerosis. Alcohol probably also reduces the inflammatory component of the disease and the risk of complicating blood clots.
The atherosclerotic process begins with deposition of fats, especially LDL-C, within the arteries, accompanied by inflammation (accumulation of inflammatory cells, the macrophages). As this disease plaque thickens, blood flow is slowed, reducing the delivery of oxygen and nutrients to the tissues the artery had contracted to supply. Eventually, with roughening of the plaque surface or rupture of the plaque, a blood clot may form, completely obstructing blood flow, causing the death of the tissue beyond. In the heart, this would be a heart attack (myocardial infarction); in the brain, an ischemic stroke. HDL-C acts as a trash collector, picking up LDL-C from the arterial wall and carting it off for excretion.
Returning to the Rochester mice, we find them divided into three identical groups, all male. None smoke. All have the same diets and lifestyles, except for alcohol. One group receives no alcohol, but does get calories equal to the other two groups. A second group is given the equivalent of two drinks daily, seven days per week. A third group consumes seven drinks per day, but only on weekends. After a suitable period, blood fats are measured and arteries are examined.
Compared to the teetotalist mice, the protective HDL-C in both drinking groups increased considerably. The noxious LDL-C, however, was favorably and significantly decreased in the daily-moderate drinkers, but ominously and significantly elevated in the weekend-bingers. The daily-moderates also showed a decrease in the size of their atherosclerotic plaques and increase in blood-flow capacity, and a decrease of inflammatory cells – all favorable signs. The opposite conditions prevailed among the bingers.
Although only one study, and in need of confirmation, this report dramatically confirms epidemiologic observations that patterns of drinking are highly important, in particular that binge drinking of even the same quantity of alcohol is harmful to health, yet regular moderate drinking is healthful. The truth of the J-shaped curve has been accordingly refined, in keeping with the biological phenomenon called hormesis: a modest dose may be healthful when a larger dose of the same substance is toxic.
