Over the last three decades, a number of studies have shown an association between moderate drinking and a lowered risk for heart attack, heart and circulatory diseases, stroke, type 2 diabetes, and gallstones.
But the research results lead to a kind of two-edged sword when it comes to alcohol. Alcohol may have some health benefits, but it may also lead to abusive drinking and other diseases. Because there is no sure way to know who will develop an abuse problem, the American Heart Association (AHA) and other experts don't recommend starting to drink if you don't already do so.
Moderate drinking is defined as no more than one drink a day for women and two drinks a day for men. Pregnant women should avoid all alcohol as it can lead to birth defects. A drink is considered 12 ounces of regular beer, 4 to 5 ounces of wine, or 1.5 ounces of 80-proof distilled spirits.
Moderation is defined differently for men, women, and older adults because alcohol’s effects depend on how the body absorbs and metabolizes alcohol. Older adults metabolize, or breakdown, alcohol more slowly than younger people. This means alcohol stays in their bodies longer. A person's height and weight are critical in alcohol absorption. The smaller and lighter you are, the more quickly alcohol is absorbed.
People respond differently to alcohol for other reasons besides height and weight. Your gender, age, genetics, overall health, the amount of alcohol you drink, when you drink it, and any history of problem drinking can affect your reaction to alcohol.
When alcohol is consumed, it passes from the stomach and small intestine into the blood and is transported to all organs of the body. Alcohol is water soluble, so it enters your organs in proportion to the amount of water they contain. The more water available in the organs to absorb alcohol, the less alcohol remains in your bloodstream.
Your liver does most of the work of breaking down, or metabolizing, the alcohol you drink. The liver removes alcohol from your body so it won't damage other organs. The liver can break down only a certain amount of alcohol per hour, regardless of the amount you drink. A very small percentage of alcohol escapes this metabolic process and is eliminated unchanged in your breath, sweat and urine. (This alcohol can be detected in a breathalyzer test.) Until all the alcohol in the body has been metabolized, it stays in the brain and other tissues of the body and continues to cause effects.
In general, women and older men have less water in their organs than younger men. Therefore, less alcohol enters their organs and more alcohol remains in their bloodstream. Younger women produce less of a stomach enzyme called alcohol dehydrogenase, which breaks down alcohol in the stomach. This means more alcohol is available to be absorbed into the blood. As a result, a young woman will have a higher blood alcohol level than a man of the same age who drinks the same amount of alcohol.
Heredity may play a role in how alcohol and your body interact. Moderate drinkers who have genes that cause a slower metabolism of alcohol are at much lower risk for cardiovascular disease than moderate drinkers who have genes that cause rapid metabolism of alcohol.
Alcohol is metabolized more slowly than it is absorbed. Absorption is slowed when you drink alcohol during or immediately after a meal. The slower absorption allows the liver to metabolize alcohol at a rate that prevents more of it from reaching other organs.
Because the liver metabolizes alcohol, people with liver disease are more sensitive to drinking. Certain medications may trigger adverse reactions if you drink while taking them. Alcohol affects the metabolism of a wide variety of medications by increasing the activity of some and decreasing the activity of others. Most notably, heavy alcohol consumption when taking acetaminophen (Tylenol) can lead to liver damage.
Additionally, for people with a history of alcoholism, the danger of drinking is far greater than the possible cardiovascular benefits.
The AHA says moderate alcohol consumption helps protect against heart disease by raising HDL ("good") cholesterol and reducing plaque accumulations in your arteries. Alcohol also has a mild anticoagulating effect, keeping platelets from clumping together to form blood clots. According to the National Council on Alcoholism and Drug Dependence, moderate drinking may lower the risk for coronary heart disease among men older than 45 and women older than 55. Moderate consumption provides little, if any, health benefit for younger people, and the risk of alcohol abuse increases when drinking starts at an early age. Remember that alcohol doesn't provide complete protection against heart disease or compensate for negative health habits like smoking, which lowers HDL and increases the risk of harmful blood clots.
Moreover, the AHA says, regular physical exercise also can raise HDL. And excessive drinking can raise triglyceride levels, increase blood pressure, and raise the risk for stroke.
There's no fat in alcohol. That's the good news. But there are 7 calories per gram, and that translates to between 100 and 150 calories for the alcohol in a typical beer, wine, or spirits drink. Add to that the calories in drink mixers, and drinking could be a setup for weight gain.