Authors of a review published in Future Cardiology state that ‘An inverse association between moderate alcohol intake and cardiovascular risk, in particular coronary disease and ischemic stroke, has been demonstrated in many epidemiologic studies. In addition, several not primarily vascular diseases are also known to occur less frequently in moderate drinkers than in nondrinkers, whereas excess drinking is unquestionably harmful. As a consequence, clarification as to exact dosage limits and mechanisms regarding the benefit of moderate alcohol intake versus its harmful effects at higher doses is often sought.
Alcohol affects several biochemical factors that have potential cardio-protective benefits, including lipids, platelet aggregation (blood clotting), fibrinogen, tissue-plasminogen activator, plasminogen-activator inhibitor and omega-3 fatty acids. Wine possibly acts through mechanisms that might provide additional cardiovascular benefits. Mechanisms supporting the protective effect of moderate alcohol intake against cardiovascular disease, and epidemiologic evidence concerning the relationship between alcohol dosing and vascular and all-cause mortality are discussed in this review’.
The review conclusions include
The rates of vascular and total mortality are lower for people who drink low-to-moderate amounts of alcoholic beverages than for individuals who do not drink at all.
The cardioprotective nature of alcohol has been attributed to both its antithrombotic properties and its ability to increase high density lipoprotein (HDL = “good” cholesterol) levels.
Moreover, wine (or other antioxidant rich alcoholic beverages) due to its polyphenols content, might offer additional advantages and greater cardiovascular benefits than ethanol alone.
Available epidemiologic data, based at the moment on observational studies, confirm the hazards of excess drinking, but also indicate the existence of a potential window of alcohol intake that may confer a net beneficial effect of drinking, at least in terms of survival, both in men and in women.
Methodological limitations of an observational study design, the role of uncontrolled confounding factors, and the optimal choice of the reference group are important issues to be carefully considered in future studies on alcohol and health.
Besides insisting on the control of risk factors, abstainers should be informed that in the absence of contraindications and in the context of healthy eating and lifestyle, low-to-moderate, non-bingeing consumption of alcoholic beverages may contribute to better health.
Individuals who are already regular light-to-moderate consumers of alcoholic beverages should be encouraged to continue.
The hazards of excess drinking should always be highlighted, and heavy drinkers should be pushed to cut their consumption to a low-to-moderate level.
Source: Alcohol consumption and cardiovascular risk: mechanisms of action and epidemiologic perspectives. Di Castelnuovo A, Costanzo S, di Giuseppe R, de Gaetano G, Iacoviello L. Future Cardiol. 2009 Sep;5(5):467-77.
Alcohol consumption, hypertension, and total mortality among women
Summary: The authors state that moderate alcohol consumption is associated with a reduced risk of total mortality among Caucasian women, irrespective of hypertension (high blood pressure). Whether moderate alcohol consumption is associated with a reduced risk of total mortality among African-American or hypertensive women is unclear. They conducted a prospective study among 10,576 black and 105,610 white postmenopausal women from the Women’s Health Initiative (WHI), without a history of cancer or cardiovascular disease, who completed the baseline examinations in 19941998.
During the mean 8 years of follow up, 5,608 women died. Moderate drinking (1 to <7 drinks/week) was associated with a lower risk of total mortality among Caucasians (hazard ratio (HR) = 0.81, 95% confidence interval (CI) = 0.720.91) and hypertensives (HR = 0.76, 95% CI = 0.650.87) as compared with lifetime abstention from alcohol. Among African-American moderate drinkers the risk of total mortality was HR = 0.94, 95% CI = 0.671.3. Current drinking (<1 drink/month or greater) was associated with a lower risk of mortality among Caucasians, including hypertensives and non-hypertensives, and hypertensive African Americans (HR = 0.74, 95% CI = 0.540.99) but not among non-hypertensive African Americans (HR = 1.31, 95% CI = 0.792.16). The stratified comparisons among African Americans were affected by the low prevalence of moderate drinking (14.6%) and the low mortality rate (37.5/10,000) among the non-hypertensive lifetime abstainers.
The authors conclude that moderate drinking is associated with a lower risk of total mortality among Caucasian women. Current drinking is associated with a lower risk of total mortality among Caucasians, regardless of hypertensive status, and hypertensive but not non-hypertensive African-American women. The latter observation was affected by the low mortality rate among the African-American non-hypertensive lifetime abstainers.
Professor R Curtis Ellison comments: There have been conflicting data as to the degree that the inverse association between moderate drinking and both coronary disease and total mortality seen among whites occurs among African-Americans. In an analysis based on the NHANES Epidemiologic Follow-Up Study (NHEFS) Sempos et al1 found no evidence of lower mortality among African-Americans who consumed alcohol, but the number of subjects consuming more than occasional alcohol was very small. Klatsky et al2, using data from the Kaiser Permanente Study, found similar J-shaped curves for the association between alcohol and heart failure for whites, Asians, and African-Americans.
The current paper by Freiberg et al, from the large Women’s Health Initiative, shows that all white women and African-American women who were hypertensive had the expected J-shaped curve, but the non-hypertensive African-American women did not show lower mortality to be associated with moderate alcohol consumption. As the authors state, “Whether this result truly reflects a lack of ‘benefit’ of moderate alcohol consumption among African Americans with regard to total mortality or is the function of the smaller sample size combined with the low prevalence of alcohol consumption in this population is not clear.” Despite the large number of African-Americans in this study, the number of deaths in non-hypertensives was rather small, and the number of moderate drinkers was low.
Based on all currently available data, we believe that it is still not clear whether or not African-Americans respond differently to alcohol in terms of mortality than do whites. And if they do, it is not certain whether it relates to differences in their drinking pattern or to biologic differences.
Source: Freiberg MS, Chang Y-F, Kraemer KL, Robinson JG, Adams-Campbell LL, Kuller LL. Alcohol consumption, hypertension, and total mortality among women. Am J Hypertens 2009; 22:1212-1218.