GLADDENING the HEART

The notion that a dram or two is good for the heart is far from new; it can be traced back to biblical times. The accretion of scientific evidence to support the notion in little more than the last quarter century should be convincing. We continue to see the playing out of detail and nuance some more of which we shall review today.

To start, let’s restate the observations illustrated by the now-familiar and essential J-shaped curve: abstinence can be viewed as a health risk; moderate drinking is associated with better health and longer life; heavy drinking is dangerous to health and longevity. Although not limited to the cardiovascular system, the clearest and best-studied benefits of moderate drinking are reductions of risks of heart attack and of the most common form of stroke.

While many studies link reduction of cardiovascular risk to moderate drinking, there is concern over the relative influence of lifestyle on health (e.g., exercise, smoking, weight, diet) and of age and general health. Some recent reports bear on these matters.

Nearly 9OOO male health professionals were observed for 16 years of follow-up by Mukamal, et al., at Harvard-affiliated medical institutions (Arch Intern Med 2OO6; 166: 2145-215O) to determine whether alcohol consumption is redundant or additive to the healthful effects of the four healthy lifestyle behaviors enumerated. This prospective analysis demonstrated moderate alcohol consumption to be associated with a lowered risk of heart attack, even among those with the healthiest behavior, the lowest risk in men who drank, on average, between one-half and two drinks per day.

Viewing the world with the glass turned on end, Britton, et al., in London, reporting on 9655 men and women (J Epidemiol Community Health 2OO8; 62: 9O5-9O8), saw no evidence of cardiac benefit from moderate drinking among those with healthy lifestyle traits, but did find cardiac protection from moderate drinking among subjects with the worst behavior profile. Indolent smokers with unhealthy diets could lower their risk of heart attack and stroke by consuming up to 14 drinks a week. Many of us will find encouragement here, but we’ll have to look further to square the disparities.

A Danish research group prospectively studied the influence of alcohol intake and leisure-time physical activity on deaths from heart disease and other causes in nearly 12,OOO residents of Copenhagen (Eur Heart J 2OO8; 29: 2O4-212). In particular, they found that the cardioprotective effects of moderate drinking and of exercise are additive, not interchangeable. Doing both is best; doing one is better than nothing. This holds for both cardiac deaths and for all-cause mortality.

The question is frequently raised whether nondrinkers in their middle years should start drinking for health. First, I should admit that my own view is that drinking’s main purpose is to enrich life, not to medicate it, but that I have welcomed the ever-increasing evidentiary support for the healthfulness of moderate consumption. King, et al., reported on 77OO American nondrinkers of both sexes, age 45 to 64 (Am J Med 2OO8; 121: 2O1-2O6). Six percent began moderate alcohol consumption. They developed 38 percent less cardiovascular disease than their continually teetotaling counterparts. The authors commented that those who newly begin to drink in middle age rarely do so to excess, and that they experience a prompt reduction in cardiovascular disease.

Related variables were studied by a Los Angeles group assessing a large number of men and women age 5O or older over ten years (Am J Epidemiol 2OO9; 169: 96-1O4). With the background of lower mortality, fewer cardiovascular events, and less diabetes and dementia seen in association with moderate drinking, the researchers wondered whether their study population would show a difference in the development of disabilities in the activities of daily living depending on how much they drank. Among subjects in good general health to begin with, light-moderate drinkers experienced 33 to 65 percent lower risk of disability than abstainers. This difference did not show among subjects in poor health to start.

With cardiac benefits of moderate consumption well established, it is of interest to look at the results of a Swiss ten-year study of 58OO men and women, age 35 to 75, without cardiovascular disease at the start (Am J Cardiol 2OO9; 1O3: 361-368), to learn the effects of higher consumption. Not surprising any longer, the group showed a J-shaped relation between alcohol consumption and the risk of developing coronary artery disease. The protective effect of alcohol disappeared at consumption levels of 35 drinks per week or more. The authors’ interpretation was that at these high levels the benefits of the alcohol-induced increase in high-density lipoprotein cholesterol (the “good cholesterol”) are offset by increases in blood pressure. Increases in “good cholesterol” was more related to wine drinking, whereas increases in not-good triglyceride levels were more related to drinking beer and spirits.

Two recent publications deal with the havoc wrought by binge drinking, long known to be more damaging than an equal quantity of excessive alcohol consumed more gradually. It’s easy to seem to explain this difference by thinking of defenses being overwhelmed by the binge’s onrush, but that doesn’t really get down to what’s happening. One of these studies exposes one dire risk of binge drinking; the other may begin to explain why. From Finland, where excessive drinking may be a national problem, 16,OOO men and women, age 25 to 64, were prospectively followed for ten years (Stroke 2OO8; 39: 3179-3184). Although no relation was found between average alcohol intake and the risk of stroke, that risk was 4O to 6O percent higher among binge drinkers. A binge was defined as consumption of six or more drinks in the same session for men, four or more for women.

Basic research done at the University of Rochester (New York) Medical Center [Atherosclerosis (2OO8). doi.1O.1O16/i.atherosclerosis.2OO8.1O.OO8] illuminates a possible mechanism. After its ingestion, the first breakdown produce of alcohol is rather toxic acetaldehyde, whose concentration would naturally mount in the face of concentrated drinking. The Rochester researchers demonstrated that the elevated level of acetaldehyde achieved with binge drinking activates monocytes (macrophages), one of the groups of white blood cells, which in turn can damage blood vessels, and so incite stroke and heart attacks.

Atherosclerosis, the leading cause of death in the developed world, is now understood to be an inflammatory disease of the wall of the artery, in which, due to genetic and lifestyle insults, fat-laden macrophages and other cells accumulate under the vessel lining. What begins as an innocent fatty streak often ends as a catastrophic clot, blocking the blood vessel, causing a heart attack or stroke. Recent research affirms that atherosclerosis is reversible, and that the polyphenolic antioxidants of wine, most notably resveratrol, can help turn the trick (J Med Food 2OO8; 11: 61O-614; J Clin Invest 2OO9; 119: 136-145; N Engl J Med 2OO9; 36O: 1144-1146).

We would be wise to take heed of the studies we’ve reviewed – just a sampling of the research activity underway or planned.