Alcohol’s Effect on Health and Performance

Alcohol’s effect on health and quality of life has been on the public-health radar screen for decades. The notion that moderate alcohol consumption might even offer some health benefits was first explored as far back as the early 1970s. Since then, hundreds of studies on alcohol and health have been conducted, many confirming the theory that drinking alcohol can positively impact conditions such as cardiovascular disease and diabetes.

But is alcohol beneficial for everyone? Not necessarily, say the experts. "It’s an individual equation each time," says Monica Gourovitch, PhD, senior vice president of scientific affairs for the Distilled Spirits Council of the United States. "It’s not [the case] that the benefits outweigh the risks for every individual; some people should not drink at all," points out Gourovitch. So, who exactly is a candidate for safe, moderate drinking, and who is not?

Trends in Consumption
In a nation where social drinking abounds, the reality is that fewer Americans are drinking alcohol today than 50-100 years ago, according to recent estimates from the Centers for Disease Control and Prevention (CDC 2005). In 2002, 55% of U.S. adults described themselves as regular drinkers of alcohol, whereas 45% said they did not ever imbibe (CDC 2005).

Does this mean that more people are now aware of the risks of alcohol abuse and, as a result, are choosing to abstain? Perhaps. Certainly, alcohol continues to be the most abused drug in the United States, and heavy drinkers know full well how difficult an addiction it can pose. On the other hand, according to a recent fact sheet published in the Journal of the American Dietetic Association, more than 100 million American adults currently drink alcohol in a responsible manner (American Dietetic Association [ADA] 2005). So it may be that many informed consumers realize that moderate alcohol intake can be part of a healthy lifestyle.

Most experts say that when it comes to who can safely drink and who cannot, it all depends on the amount consumed, as well as the age and other characteristics of the consumer. "Prolonged (heavy) consumption [of alcohol] can lead to cellular changes in the liver, heart, brain and muscles and result in cirrhosis, pancreatitis, irregular heart beats, stroke and malnutrition," explains Nancy Clark, MS, RD, author of Nancy Clark’s Sports Nutrition Guidebook (Human Kinetics 2003). Clark notes that even moderate drinkers have a higher risk of oral cancer, and women who drink may have a higher risk of breast cancer. However, moderate drinking can also enhance health status, according to the scientific research described in the following sections.

The Heart Health Benefits of Alcohol
One of the most publicized benefits of alcohol intake involves cardiovascular health. In fact, the inverse association between moderate alcohol consumption and coronary heart disease has been well established in a review of the scientific literature (Rimm et al. 1996). This analysis of the studies performed on alcohol and heart health found that as little as 1-2 weeks of moderate alcohol consumption could have a positive effect on high-density lipoprotein (HDL) cholesterol (the "good" cholesterol) levels. "No drug or other lifestyle change has such a quick impact [on HDL levels]," according to the researchers (Rimm et al. 1996).

This cardioprotective benefit is especially positive in people who regularly exercise, according to the research review. However, it should be noted that the greatest benefits were noted in people who had the lowest HDL levels at the start of the study period (Rimm et al. 1996).

The reason alcohol may be beneficial to the heart is still something of a mystery to the medical community. The common denominator found in the research is that moderate alcohol consumption appears to increase HDL cholesterol levels.

"There is convincing evidence that [consuming] one to two alcoholic drinks per day increases HDL cholesterol by as much as 15%-20%," according to Eric Rimm, MD, associate professor of epidemiology and nutrition at the Harvard School of Public Health. This, in turn, reduces narrowing of the arteries caused by plaque (atherosclerosis) and decreases the propensity for blood clotting, a common cause of heart attacks.

Alcohol’s Effect on Mortality
Another finding in the scientific research is that drinking alcohol in a moderate fashion may decrease death rates. According to the CDC, the lowest all-cause mortality rates occurs in people who ingest one to two drinks per day (CDC 2005). Furthermore, the lowest coronary heart disease mortality rate also occurs at an intake of one to two drinks per day (CDC 2005). However, there is another, darker side to the issue of drinking and death rates. The same research has shown that morbidity and mortality are highest among those who drink large amounts of alcohol (CDC 2005).

Although the amount imbibed plays an important role in mortality rates, drinking patterns hold equal weight. "You can’t save up your drinks and use them all over the weekend," warns Dawn Jackson Blatner, RD, a national media spokesperson for the ADA. In other words, the benefits to mortality come from moderate, incremental alcohol consumption throughout the week, meaning only one to two servings per day, not four or five in one drunken sitting!

Alcohol and Diabetes
Some experts also point to the positive effect that alcohol consumption may have in preventing diabetes in some adults. "In the general U.S. population, alcohol has been found to reduce the risk for type 2 diabetes, because it impacts glucose metabolism," explains Rimm. With type 2 diabetes mellitus now a global epidemic, there is hope among researchers that alcohol may have the potential to stave off the onset of this life-threatening disease.

In some studies, alcohol intake (again, only one to two drinks per day) has been shown to reduce type 2 diabetes risk factors, specifically high insulin levels (hyperinsulinemia) and reduced insulin sensitivity. For example, a study that appeared in The Journal of the American Medical Association examined whether daily consumption of low to moderate amounts of alcohol (0, 15 or 30 grams [g] per day) influenced fasting insulin, glucose concentrations and insulin sensitivity in 51 nondiabetic postmenopausal women (Davies et al. 2002). After 8 weeks, the greatest impact was observed in the group that drank 30 g of alcohol (about two drinks) a day. The researchers concluded that fasting insulin levels decreased and insulin sensitivity improved as a result of regular, moderate alcohol intake compared with abstinence (Davies et al. 2002).

How Much Is Too Much?
Over and over, nutrition experts and researchers reiterate the same message: Drink alcohol in moderation. But what exactly is considered moderate intake?

According to the latest U.S. government dietary guidelines, moderate alcohol intake is defined as no more than one drink per day for women and no more than two drinks per day for men—ideally taken with meals (U.S. Department of Agriculture 2005). Apparently, many Americans are unaware of how much alcohol is contained in a standard drink. According to a national survey conducted in 2000, the majority of Americans aged 21 and older (54%) did not know that standard servings of distilled spirits, wine and beer all contain the same amount of alcohol (ADA 2005).

When it comes to alcohol consumption, moderation is the key, say our experts. Drink a glass of water for each alcoholic drink you consume. Be responsible when imbibing alcohol, and you will save calories, stay hydrated and have a reason to hoist a drink to your health!*

References
American Dietetic Association (ADA). 2005. Nutrition fact sheet: Adult beverages consumption: Making responsible drinking choices. Journal of the American Dietetic Association.
American Heart Association (AHA). 2006. Diet and Lifestyle Recommendations, Revision 2006: A Scientific Statement From the American Heart Association Nutrition Committee. www.circ.ahajournals.org; retrieved Dec. 3, 2006.
Centers for Disease Control and Prevention (CDC). 2005. Behavioral risk factor surveillance system: Surveillance for certain health behaviors among selected local areas—United States, MMWR, 53 (SS-05); www.cdc.gov/brfss.
Davies, M.J., et al. 2002. Effects of moderate alcohol intake on fasting insulin and glucose concentrations and insulin sensitivity in postmenopausal women. The Journal of the American Medical Association, 287 (19), 2559-62.
Rimm, E.B., et al. 1996. Review of moderate alcohol consumption and reduced risk of coronary heart disease: Is the effect due to beer, wine or spirits? British Medical Journal, 312 (7033), 731-36.
Suter P. 2001. Alcohol and mortality: If you drink, do not forget fruits and vegetables. Nutrition Reviews, 59 (9), 293-97.
Tremblay, A., & St-Pierre, S. 1996. The hyperphagic effect of a high-fat diet and alcohol intake persists after control for energy density. American Journal of Clinical Nutrition, 63 (4), 479-82.

U.S. Department of Agriculture, U.S. Department of Health and Human Services. 2005. Dietary Guidelines for Americans 2005. Washington, D.C.