Alcohol and cardiovascular health

Abstract

The substantial medical risks of heavy alcohol drinking as well as the probable existence of a less harmful or safe drinking limit have been evident for centuries. Modern epidemiology studies suggest lowered risk of morbidity and mortality among lighter drinkers. Thus, defining “heavy” drinking as ≥ 3 standard drinks per day, the alcohol–mortality relationship is a J-curve with risk highest for heavy drinkers, lowest for light drinkers and intermediate for abstainers. A number of non-cardiovascular and cardiovascular problems contribute to the increased mortality risk of heavier drinkers. The lower risk of light drinkers is due mostly to lower risk of the most common cardiovascular condition, coronary heart disease (CHD). These disparate relationships of alcoholic drinking to various cardiovascular and non-cardiovascular conditions constitute a modern concept of alcohol and health. Increased cardiovascular risks of heavy drinking include: (1) alcoholic cardiomyopathy, (2) systemic hypertension (high blood pressure), (3) heart rhythm disturbances, and (4) hemorrhagic stroke. Lighter drinking is not clearly related to increased risk of any cardiovascular condition and, in observational studies, is related to lower risk of CHD, ischemic stroke, and diabetes mellitus. A protective hypothesis for CHD is supported by evidence for plausible biological mechanisms attributable to ethyl alcohol. International comparisons and some prospective study data suggest that wine is more protective against CHD than liquor or beer. Possible non-alcohol beneficial components in wine (especially red) support possible extra protection by wine, but a healthier pattern of drinking or more favorable risk traits in wine drinkers may be involved.

Introduction

There is a basic disparity in alcohol–health relations between effects of lighter and heavier drinking [1], [2], [3]. While it has been evident for millenia that heavy uncontrolled drinking carried major social and medical risks, it was observed that light drinking was less hazardous or that there was a safe or sensible limit for most persons. Since no amount is safe for all persons, the term “sensible” may be more appropriate. Benefit from lighter alcohol intake is a more recent concept, developing from evidence with respect to coronary heart disease and other athero-thrombotic disorders.

Disparities in relations between alcohol drinking and cardiovascular (CV) conditions make it desirable to consider several disorders separately. These include alcoholic cardiomyopathy, systemic hypertension (HTN), arrhythmias, stroke, athero-thrombotic disease — especially coronary artery disease (CAD), and heart failure (HF). A historical approach is instructive because of previous interpretive pitfalls. In this article an operational definition of “moderate” and “heavy” drinking is based upon the level of drinking in several epidemiologic studies above which net harm is usually seen [1], [2], [3]. While the term “drink” is imprecise, this alcohol unit is used, since most persons think in terms of “drinks,” not grams of alcohol. Less than 3 drinks per day is called “light” or “moderate” drinking, and 3 or more drinks per day is called “heavy” drinking. The amount of alcohol is approximately the same in the usual drink of wine, liquor, or beer. Thus, a 4 ounce glass of table wine at 13% alcohol, 1¼ oz of distilled spirits at 40% alcohol, and 12 oz of U.S. beer at 5% alcohol all contain about 12.5–15 ml of pure ethyl alcohol.