A Hearty Buzz from Alcohol
By Marjet Heitzer, Ph.D.
The Plateau-proof Diet Foundation
In recent years, moderate consumption of alcohol, particularly red wine, has been associated with various health benefits including lowering the risk of coronary heart disease (CHD, atherosclerosis), ischemic stroke (interrupted blood flow to the brain due to a blood clot or bursting of a blood vessel) and cerebral thrombosis (blood clot in the brain). For example, light to moderate drinkers have less risk of developing CHD than abstainers (1). However, heavy drinking actually raises a person's risk of developing CHD. This article will examine scientific evidence associated with alcohol consumption and CHD. However, this article is by no means promoting increased alcohol consumption in order to attain cardioprotection. Alcoholism is associated with many more health problems such as liver cirrhosis, cancer, neurological diseases as well as heart complications like alcoholic cardiomyopathy (weakening of the heart muscle seen in some chronic alcoholics) and high blood pressure. Individuals should discuss alcohol consumption with their physician.
Part of the epidemiological evidence associated with the benefits of alcohol consumption, particularly red wine, comes from the French Paradox (2). Despite the high amounts of saturated fat in their diet, the French have a relatively low incidence of CHD. Comparing the eating and drinking habits of European countries that have low rates of CHD resulted in a common factor: consumption of more red wine as compared to other countries. This led to the question: Could red wine consumption lead to heart health benefits?
In the Copenhagen City Heart Study, 13,285 men and women were observed for twelve years (3). Individuals, who drank wine, had 50% less CHD. In this study, beer and spirit drinkers had no reduction in CHD. However, another similar study indicated that moderate beer consumption decreased the risk of CHD by 22% (4).
So what is CHD? Atherosclerosis is the accumulation of fatty plaques in blood vessels, leading to decreased blood flow to the heart (See Above Figure). One of the initial steps in the progression of atherosclerosis is the inability of the blood vessels to relax or vasodilate. Smoking, hypertension (high blood pressure), high cholesterol, and diabetes are just a few complications that may be responsible for reduced vasodilation. Proliferation and migration of smooth muscle cells underneath the endothelium (cells lining the blood vessels) results in decreased blood vessel relaxation and a thickening of the blood vessel wall. In the end, the plaque ruptures and leads to either a heart attack or stroke.
In laboratory studies, alcohol improves endothelial cell function and inhibits vascular smooth muscle cell proliferation and migration, resulting in more relaxed blood vessels (5). Furthermore, red wine reduced the production of endothelin-1, a protein involved in blood vessel vasoconstriction (6). Finally, alcohol consumption leads to decreased LDL (bad cholesterol) oxidation, increased HDL (good cholesterol) concentrations, and decreased platelet aggregation, resulting in a better blood lipid profile and less plaque formation (5). Taken together, alcohol itself improves vascular function, resulting in reduced risk of developing CHD.
So, why does wine especially red wine have additional health benefits as opposed to beer or spirits? Studies using dealcolized red wine showed that some of the cardioprotective characteristics of red wine are independent of the alcohol. Along with alcohol, red and white wine is composed of many other chemicals from the grape, including polyphenols that act as antioxidants. However, red wine typically has more antioxidant polyphenols than white wine. Plant polyphenols are responsible for the color of the grape. Red wine has a variety of polyphenols including resveratrol (stilbene) and flavinoids. The antioxidant function of red wine flavinoids decreases LDL (bad cholesterol) oxidation (7). Because oxidized LDL reduces blood vessel relaxation, it is a crucial step leading to heart disease. Along with reducing oxidized LDL concentrations, polyphenols may also reduce cholesterol absorption the gut, leading to decreased serum cholesterol concentrations. Finally, grape polyphenols decrease plasma triglyceride concentrations by 39% (8). All of these changes may result in suppression of atherosclerosis, thus reduced risk of developing CHD.
What is moderate and heavy consumption of alcohol? Moderate consumption of alcoholic beverages (1-2 drinks/day) 3 to 4 days per week results in a 30% reduction in risk of developing CHD and a 20% reduction in the risk of developing ischemic stroke. Each drink consists of 1.5 ounces of liquor, 5 ounces of wine, or 12 ounces of beer. However, heavy drinking as well as binge or weekend drinking (5+ drinks for women and 9+ drinks for men) are not associated with any cardioprotective effects. In fact, heavy and binge drinkers had a higher risk of developing CHD as compared to abstainers.
Do only healthy individuals benefit from moderate alcohol consumption? Healthy individuals along with patients with a history of heart attack or diabetes all may benefit from moderate drinking. Men with a history of ischemic heart disease had an increase in blood vessel size after ingestion of both red and white wine (9). Furthermore, in a model of insulin resistance, insulin resistant rats benefited from the consumption of alcohol, red wine polyphenols, or both (10). In this model of insulin resistance, rats are fed a high fructose diet that leads to metabolic syndrome followed by glucose intolerance, visceral obesity, hypertension, insulin resistance, and dyslipidemia. Drinking alcohol or red wine polyphenols led to increased insulin sensitivity, in turn resulting in lower blood glucose and normal blood pressure. Rats that consumed alcohol alone had decreased insulin resistance.
This article addresses the heart healthy benefits of moderate alcohol consumption. Alcohol consumption only for the purpose of cardioprotection is not advised, and people who abstain from drinking alcohol should not start drinking alcohol for the health benefits. Furthermore, increased consumption of alcoholic beverages does not lead to increased protection. In fact, as previously mentioned, heavy or binge drinking leads to increased risk of developing CHD.
The Plateau-Proof Diet (http://www.plateauproofdiet.com) considers the caloric contribution of beverages as well as foods. As with anything you consume while participating in The Plateau-Proof Diet (http://www.plateauproofdiet.com), consult the CP and FP tables before consumption of any beverage containing alcohol or not.
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10. Al-Awwadi NA, Bornet A, Azay J, et al. 2004 Red wine polyphenols alone or in association with ethanol prevent hypertension, cardiac hypertrophy, and production of reactive oxygen species in the insulin-resistant fructose-fed rat. J Agric Food Chem 52:5593-7
About the author:
Dr. Marjet Heitzer is a biomedical scientist specialized in cancer and endocrine research. She is the founding editor of 'Trimming America', the free journal of 'The Plateau-proof Diet Foundation'. She is a strong proponent of reversing obesity and some of its comorbidities, including type II diabetes and hypertension, with a lifestyle change that has healthy dieting at its core.