Alcohol and cardiovascular disease

Total recorded alcohol per capita consumption, in litres of pure alcohol.^[1]

Excessive alcohol intake is associated with an elevated risk of alcoholic liver disease (ALD), heart failure, some cancers, and accidental injury, and is a leading cause of preventable death in industrialized countries.^[2] There is controversy about studies that showed beneficial effects of alcohol consumption.^[3]

Some Epidemiological and short term experimental studies have shown drinkers who consume one to two drinks per drinking day have a beneficial association with ischemic heart disease compared to never-drinkers.^[4] Furthermore, regular consumption of light to moderate dose of alcoholic beverages (1 drink/day for women or up to 2-drinks/day for men) has been associated with reduced incidence of cardiovascular events and all-cause mortality in cardiovascular patients. However, cardiovascular patients who do not regularly consume alcohol are not encouraged to start drinking due to lack of controlled intervention studies and evidence.^[5]

Possible mechanisms of alcohol cardioprotection[]

Extensive epidemiological studies have demonstrated the cardioprotective effect of alcohol consumption. However the mechanism by which this occurs is not fully understood. Research has suggested several possible mechanisms,^{[6][7][8][9][10][11][12][13][14][15][16][excessive citations]}including the following.

I. Alcohol improves blood lipid profile.

A. It increases HDL ("good") cholesterol. However, the increase of HDL cholesterol is dose and disease dependent. Some populations have to consume approximately 30g alcohol per day (moderate dose for men and high dose for women) in order to increase HDL cholesterol. For some diabetic patients and postmenopausal populations, a small dose of alcohol is effective to increase HDL cholesterol level.

B. It decreases LDL ("bad") cholesterol for both healthy and patient populations though the effect is still under debate.

C. It improves cholesterol (both HDL and LDL) particle size^[17]

II. Alcohol decreases thrombosis (blood clotting).

A. It reduces platelet aggregation.

B. It reduces fibrinogen (a blood clotter). This is independent of beverage type and applies to long-term wine consumption.

C. It increases fibrinolysis (the process by which clots dissolve).

III. Alcohol acts through additional ways.

A. It reduces coronary artery spasm in response to stress.

B. It increases coronary blood flow.

C. It reduces blood pressure.

D. It reduces blood insulin level.

E. It increases estrogen levels

There is a lack of medical consensus about whether moderate consumption of beer, wine, or distilled spirits has a stronger association with heart disease. Studies suggest that each is effective, with none having a clear advantage. Most researchers now believe that the most important ingredient is the alcohol itself.^[18][19]

The American Heart Association has reported that "More than a dozen prospective studies have demonstrated a consistent, strong, dose-response relation between increasing alcohol consumption and decreasing incidence of CHD (coronary heart disease). The data are similar in men and women in a number of different geographic and ethnic groups. Consumption of one or two drinks per day is associated with a reduction in risk of approximately 30% to 50%". It also notes that total mortality goes up with higher doses: „The J-shaped distribution for total mortality is then the sum of the protective effect on CHD mortality and the detrimental effect of high levels of consumption on these other causes of death.“^[20]

Heart disease is the largest cause of mortality in the United States and many other countries. Therefore, some physicians have suggested that patients be informed of the potential health benefits of drinking alcohol in moderation, especially if they abstain and alcohol is not contraindicated. Others, however, argue against the practice in fear that it might lead to heavy or abusive alcohol consumption. Heavy drinking is associated with a number of health and safety problems.^{[citation needed]}

Alcohol reduction[]

It is well known that alcohol consumption increases the risk of hypertension. Hence, many clinical trials examined the effect of reduction in alcohol consumption on blood pressure. Systematic review and meta-analysis have shown that effect of alcohol reduction on blood pressure is dose dependent.^[21]

I. For people who consumed 2 or fewer drinks per day, blood pressure was not significantly decreased when they reduced alcohol consumption close to abstinence.

II. For people who consumed 3 or more drinks per day, blood pressure was significantly decreased when they reduced alcohol consumption close to abstinence.

III. For people who consumed 6 or more drinks per day, reduction rate on blood pressure was the strongest when they reduced alcohol consumption close to abstinence.

IV. The effect of alcohol reduction on blood pressure is still unclear for women and hypertensive patients who consume less than three drinks per day due to limited clinical trials.

Debate over research methods[]

A logical possibility is that some of the alcohol abstainers in research studies previously drank excessively and had undermined their health. After they quit they were categorized as non-drinkers, which in turn lead to more sick people in the non-drinkers category. To test this hypothesis, a meta analysis has recategorized people accordingly. As a result there is no benefit of alcohol consumption while also showing that alcohol is detrimental to health even at low doses.^[22]

See[]

• The dose makes the poison
• Long-term effects of alcohol consumption

References[]

Further reading[]

External links[]

• USDA Dietary Guidelines for Americans 2005: Chapter 9 Alcoholic Beverages