The research on alcohol may, on the surface, present a contradictory picture. There are some benefits to moderate alcohol consumption, but on the whole they are small in comparison to the dangers of excessive intake.
The apparent heart health benefits of moderate alcohol revealed by scientific research have caused some doctors to advocate temperate drinking, but the overall effects on health are negative, especially for people who fall within the 10 percent of the population who are problem drinkers. Although moderate use of alcohol reduces risks of heart disease, it dramatically increases the risks of dying from other causes, such as cirrhosis, loss of the liver, cancer, violence, and accidents.
One of the most popular episodes shown on 60 Minutes was entitled “The French Paradox” (November 17, 1991), which reported that the consumption of wine by the French protected them against the heart disease-producing effects of their high-fat diet. The popularity of this message is of no surprise: People love to hear good news about their bad habits.
The French have 3 times less heart disease in each age category than Americans. The reasons given for this difference were: The French do not eat between meals; they take more time to eat their meals, as opposed to our habit of rapid gorging of fast foods; and they do not eat the amount of processed foods that Americans consume. Also, the French eat more of their dairy products as cheese than as milk.
One researcher, who based his ideas on rat experiments, speculated that cheese did not cause as much artery damage as milk does. Nevertheless, there is no scientific basis for such a suggestion, and the literature — such as a 1992 study in The Lancet has reputed it. Other investigators have suggested that the French love for garlic may be a life saver.
The question is this: Is there really a paradox?
The apparent difference between French and, say, American heart disease rates may be an artifact of the traditional French diet, which currently is changing, unfortunately. During the past 25 years, the French diet has become much higher in fat and lower in alcohol than in the past. Data from the United Nations Food and Agriculture Organization (FAO) has found a 40 percent increase fat consumption by the French during the past 25 years. The proportion of fat consumed in France increased 29 percent from 1961 to 1963, and 39 percent from 1986 to 1988. Heart disease takes decades to develop; thus, the heart disease rates may not have had time to catch up.
Fat consumption for Americans reached 39 percent of their total calories in the 1950s, and has remained at or above that level ever since. Since the French intake in fat and alcohol is now approaching that of the Americans, there is every reason to believe that with sufficient time they will suffer the same death rate from heart disease as we do. As of now, they have only had 4 to 6 years of high-fat eating compared to more than 50 plus years for Americans.
Pros and Cons of Alcohol Consumption
The research on alcohol may, on the surface, present a contradictory picture. There are some benefits to moderate alcohol consumption, but on the whole they are small in comparison to the dangers of excessive intake of alcohol.
Since stories of the “French paradox” began to surface, the scientific literature has reported a number of articles on the relationship between heart disease and alcohol, particularly red wine. This benefit is not new news. During my days in medical school I saw, firsthand, in autopsies, that skid-row alcoholics often had the cleanest arteries. Their diet was, of course, mostly “liquid vegetarian” in the form of alcoholic beverages, often wine. They were, however, not known for their longevity — just their clean arteries.
The research clearly shows that moderate consumption of alcohol — defined as about an ounce (20 to 30 grams) of alcohol a day, or 2 to 4 drinks a day — is associated with a 40 percent reduction in the incidence of heart disease. Beer, wine, and spirits seem to be equally protective. One of the reasons moderate alcohol consumption is associated with a reduction in the incidence of heart disease is that it raises HDL- cholesterol levels. HDL, you will recall, helps reduce the likelihood of heart disease by removing cholesterol from arteries and tissues, and out of the body through the feces. However, the HDL-raising effects of alcohol are not a straightforward equation, meaning that higher amounts of alcohol do not give you more HDL in your blood.
HDL cholesterol can be divided into smaller parts, or sub fractions. Subfraction HDL2 changes very little with alcohol intake, whereas HDL3 rises substantially when alcohol is consumed. The early research suggested that only HDL2 levels were associated with changes in a person’s risk of heart disease. However, more recent research has shown that both subfractions are associated with lower heart disease rates. Also, the more recent studies report that both types of HDL rise with alcohol consumption. However, elevation of HDL cholesterol appears to account for only half of the protective effect of alcohol. There’s more to it than just HDL.
Alcoholic beverages, especially red wine, contain powerful antioxidants. These substances prevent LDL particles from being oxidized and thus forming atherosclerotic plaque in the arteries. Antioxidants, including quercetin, epicatechin, and resveratrol, are found in the non alcoholic components of wine. Red wine diluted 1000-fold with water has been shown to inhibit LDL oxidation significantly more than vitamin E (a-tocopherol).
In addition, wine seems to thin the blood, thus preventing clots from forming. A heart attack occurs as a consequence of two unhealthy conditions: the rupture of volatile atherosclerotic plaques and the creation of large artery-blocking clots that form on top of the ruptured plaque (a process called thrombosis). While animal fats promote the rupture of plaques and the formation of large clots, alcohol decreases the clotting activity of the blood, and thus reduces the chance of a heart attack. This occurs because alcohol inhibits the tendency of platelets to aggregate to form blood clots. A study of 1600 people showed small amounts of alcohol reduced the tendency of their platelets to aggregate. This effect of thinning of the blood can also increase bleeding tendencies and may account for the increased risk of hemorrhages in heavy alcohol users.
Adverse Effects on the Heart
Heavy alcohol consumption over time can damage the liver so severely that it can no longer synthesize HDL cholesterol, dramatically increasing the risk of atherosclerosis. Excessive alcohol consumption is the second most common cause of elevated triglycerides (diabetes is the first). Moderate alcohol intake shows no consistent effects on triglyceride increases, however. Elevated triglycerides are associated with an increased risk of heart attacks, diabetes, and high blood pressure. They can become sufficiently elevated to cause inflammation of the pancreas.
Another cardiovascular disease associated with alcohol consumption is heart failure. Heart decomposition typically occurs in men between the age of 30 to 55 years who have ingested at least 3 ounces (80 g) of alcohol daily for a minimum of 10 years. Chronic excessive alcohol consumption is a major cause of cardiomyopathy–a severe form of heart muscle failure. There is also an increased incidence of sudden death that peeks at about the age of 50 in alcoholics. Bouts of heavy drinking have caused the onset of irregular heart rhythms. The most common arrhythmia associated with alcohol is atrial fibrillation.
Heavy drinking was twice as common in men and seven times as common in women who suffered brain hemorrhages. Acute heavy alcohol consumption is also characteristic of young adult stroke victims. People who decrease their alcohol intake soon lower their risk of strokes.
Social drinking is associated with a small rise in systolic blood pressure (the top number). In heavy drinkers the rise may be substantial. This increase in blood pressure may be caused by the effects of alcohol on blood pressure elevating hormones (aldosterone, renin, and catecholamines) and by an increase in the activity of nerves that cause blood vessels to constrict, thus increasing the resistance to blood flow within the arteries.
The benefits for the reduction of heart disease with the moderate use of alcohol revealed by scientific research have caused some doctors to advocate temperate drinking. But, the overall effects on health are negative, especially for people who fall within the 10 percent of the population who are problem drinkers. Obviously, we are all responsible for our own behavior and ultimately each of us must decide if we are abusing alcohol or not. When it comes to matters of public health policy, however, physicians must take a responsible and sober approach. Our position cannot be one of advocacy of alcohol, nor should we blur the issues that surround the use of alcohol, especially since alcohol is often linked to many serious social problems, such as drunken driving, violence and family abuse. Although moderate use of alcohol reduces risks of heart disease, it dramatically increases the risks of dying from other causes, such as cirrhosis, loss of the liver, cancer, violence, and accidents. For example, people over the age of 35 with a previous arrest for driving while impaired (DUI) have nearly 12 times the risk of dying in an auto accident compared to controls with no history of a DUI offense. Obviously, the first indication a person has problems with alcohol deserves serious attention. Regardless of how mixed the messages may seem, efforts by everyone in our health care system should be to decrease the use of alcohol.
Related Independent Research on Alcohol
Brewer R. The risk of dying in alcohol-related automobile crashes among habitual drunk drivers. N Engl J Med. 1994;331:513. http://www.nejm.org/doi/pdf/10.1056/NEJM199408253310806
Criqui M. Does diet or alcohol explain the French paradox? Lancet. 1994;344:1719. http://www.sciencedirect.com/science/article/pii/S0140673694928835
Frankel E. Inhibition of oxidation of human low-density lipoprotein by phenolic substances in red wine. Lancet. 1993;341:454. http://www.sciencedirect.com/science/article/pii/014067369390206V
Fuhrman B. Consumption of red wine with meals reduces the susceptibility of human plasma and low-density lipoprotein to lipid peroxidation. Am J Clin Nutr. 1995;61:549. http://ajcn.nutrition.org/content/61/3/549.short
Langer R. Lipoproteins and blood pressure as biological pathways for effect of moderate alcohol consumption on coronary heart disease. Circulation. 1992;85:910. http://circ.ahajournals.org/content/85/3/910.full.pdf
Lazarus N. Change in alcohol consumption and risk of death from all cause and from ischemic heart disease. Br Med J. 1991;303:553. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1670864/pdf/bmj00143-0027.pdf
Nestle M. Wine and coronary heart disease. Lancet. 1992;340:314. http://1.usa.gov/1a2jzyv
Regan T. Alcohol and the cardiovascular system. JAMA. 1990;264:377. http://jama.jamanetwork.com/article.aspx?articleid=382606
Renaud S. Wine, alcohol, platelets, and the French paradox for coronary heart disease. Lancet. 1992;339:1523. http://www.sciencedirect.com/science/article/pii/014067369291277F
Renaud S. Alcohol and platelet aggregation: the Caerphilly Protective Heart Disease Study. Am J Clin Nutr. 1992;55:1012. http://ajcn.nutrition.org/content/55/5/1012.full.pdf
Rimm E. Prospective study of alcohol consumption and risk of coronary disease in men. Lancet. 1991;338:464. http://www.sciencedirect.com/science/article/pii/014067369190542W
Steinberg D. Alcohol and atherosclerosis. Ann Intern Med. 1991;114:967. http://annals.org/article.aspx?articleid=704704