Monday, August 25, 2008

Binge drinking: A behavioral no-no

Binge drinkers are “once-in-a-while alcoholics.” They don’t drink every day, but when they do indulge, they go so far overboard that they sometimes fail to come back up. In simple terms, binge drinking is downing very large amounts of alcohol in a short time, not for a pleasant lift but to get drunk. As a result, binge drinkers may consume so much beer, wine, or spirits that the amount of alcohol in their blood rises to lethal levels, leading to death by alcohol poisoning. Got the picture? Binge drinking is not a sport. It’s potentially fatal behavior. Don’t do it.

The power of purple (and peanuts)

Grape skin, pulp, and seeds contain resveratrol, a naturally occurring plant chemical that seems to reduce the risk of heart disease and some kinds of cancer. The darker the grapes, the higher the concentration of resveratrol. Dark purple grape juice, for example, has more resveratrol than red grape juice, which has more resveratrol than white grape juice. Because wine is made from grapes, it, too, contains resveratrol (red wine has more resveratrol than white wine).
But you don’t need to drink grape juice or wine to get resveratrol. You can simply snack on peanuts. Yes, peanuts. A 1998 analysis from the USDA Agricultural Research Service in Raleigh, North Carolina, showed that peanuts have 1.7 to 3.7 micrograms of resveratrol per gram of nuts. Compare that to the 0.7 micrograms of resveratrol in a glass of red grape juice or 0.6 to 8.0 micrograms of resveratrol per gram of red wine.
This fact may explain data from the longrunning Harvard University/Brigham and Women’s Hospital Nurses’ Health Study, which shows that women who eat an ounce of nuts a day have a lower risk of heart disease. So let’s see — wine, grape juice, peanuts . . . decisions, decision

A lot and a little versus the middle

When scientists talk about the relationship between alcohol and heart disease, the words J-curve often pop up. What’s a J-curve? A statistical graph in the shape of the letter J.
In terms of heart disease, the lower peak on the left of the J shows the risk among teetotalers, the high spike on the right shows the risk among those who drink too much, and the curve in the center shows the risk in the moderate middle. In other words, the J-curve says that people who drink moderately have a lower risk of heart disease than people who drink too much or not at all.

That info’s nice. This is better: According to a recent report from the Alberta (Canada) Alcohol and Drug Abuse Commission, the J-curve may also describe the relationship between alcohol and stroke, alcohol and diabetes, alcohol and bone loss, and alcohol and longevity. The simple fact is that moderate drinkers appear to live longer, healthier lives than either teetotalers or alcohol abusers. Cheers!

Who should not drink

No one should drink to excess. But some people shouldn’t drink at all, not even in moderation. They include
  • People who plan to drive or do work that requires both attention and skill. Alcohol slows reaction time and makes your motor skills — turning the wheel of the car, operating a sewing machine — less precise.
  • Women who are pregnant or who plan to become pregnant in the near future. Fetal alcohol syndrome (FAS) is a collection of birth defects including low birth weight, heart defects, retardation, and facial deformities documented only in babies born to female alcoholics. No evidence links FAS to casual drinking — that is, one or two drinks during a pregnancy or even one or two drinks a week. But the fact is that about 7 percent of the babies born in the United States each year are born with birth defects independent of any parental behavior. The parents of these children may feel guilty, even though their behavior had absolutely nothing to do with the birth defect. Your decision about alcohol should take into consideration the possibility of (misplaced) lifelong guilt caused by having had a drink.
  • People who take certain prescription drugs or over-the-counter medication. Alcohol makes some drugs stronger, increases some drugs’ side effects, and renders other drugs less effective. At the same time, some drugs make alcohol a more powerful sedative or slow down the elimination of alcohol from your body.

Alcoholism: An addiction disease

Alcoholics are people who can’t control their drinking. Untreated alcoholism is a life-threatening disease that can lead to death either from an accident or suicide (both are more common among heavy drinkers) or from a toxic reaction (acute alcohol poisoning that paralyzes body organs, including the heart and lungs) or malnutrition or liver damage (cirrhosis). Alcoholism makes it extremely difficult for the body to get essential nutrients.
Here’s why:
  • Alcohol depresses appetite.
  • An alcoholic may substitute alcohol for food, getting calories but no nutrients.
  • Even when the alcoholic eats, the alcohol in his or her tissues can prevent the proper absorption of vitamins (notably the B vitamins), minerals, and other nutrients.
  • Alcohol may also reduce the alcoholic’s ability to synthesize proteins.
No one knows exactly why some people are able to have a drink once a day or once a month or once a year, enjoy it, and move on, while others become addicted to alcohol. In the past, alcoholism has been blamed on heredity (bad genes), lack of willpower, or even a bad upbringing. But as science continues to unravel the mysteries of body chemistry, it’s reasonable to expect that researchers will eventually come up with a rational scientific explanation for the differences between social drinkers and people who can’t safely use alcohol. It just hasn’t happened yet.

Sunday, August 10, 2008

The physical risks of alcohol abuse

Alcohol abuse is a term generally taken to mean drinking so much that it interferes with your ability to have a normal, productive life. The short-term effects of excessive drinking are well-known to one and all, especially to men who may find that drinking too much decreases sexual desire and makes it impossible to . . . well . . . perform. (No evidence suggests that excessive drinking interferes with female orgasm.)
Excessive drinking can also make you feel terrible the next day. The morning after is not fiction. A hangover is a miserable physical fact:
  • You’re thirsty because you lost excess water through copious urination.
  • Your stomach hurts and you’re queasy because even small amounts of alcohol irritate your stomach lining, causing it to secrete extra acid and lots of histamine, the same immune system chemical that makes the skin around a mosquito bite red and itchy.
  • Your muscles ache and your head pounds because processing alcohol through your liver requires an enzyme — nicotinamide adenine dinucleotide (NAD) — normally used to convert lactic acid, a byproduct of muscle activity, to other chemicals that can be used for energy. The extra, unprocessed lactic acid piles up painfully in your muscles.

Moderate drinking: Some benefits, some risks

Moderate amounts of alcohol reduce stress, so it isn’t surprising that recent well-designed scientific studies on large groups of men and women suggest that moderate drinking is heart-healthy, protecting the cardiovascular system (that’s science talk for heart and blood vessels). Here are some findings about the cardiovascular benefits and some of the other things moderate drinking can do for you:
  • The American Cancer Society’s Cancer Prevention Study 1 followed more than one million Americans in 25 states for 12 years to find that moderate alcohol intake had an “apparent protective effect on coronary heart disease.” Translation: Men who drink moderately lower their risk of heart attack. The risk is 21 percent lower for men who have one drink a day than for men who never drink. A similar analysis of data for nearly 600,000 women in the long-running (Harvard) Nurses’ Health Study showed that women who drink occasionally or have one drink a day are less likely to die of heart attack than those who don’t drink at all.
  • A 2003 study at Tulane University School of Public Health and Tropical Medicine shows that men who drink moderately (two drinks a day) also are less likely to die of clot-related stroke. But because alcohol reduces blood clotting, it increases the risk of hemorrhagic stroke (stroke caused by bleeding in the brain). Sorry about that.
  • According to researchers at USDA’s Agricultural Research Service (ARS) laboratory at Beltsville, Maryland, moderate drinking may lower a healthy older woman’s risk of developing diabetes.
  • Contrary to popular opinion, a 15-year, 1,700-person heart disease study at the Institute of Preventive Medicine, Kommunehospitalet in Copenhagen, Denmark, showed that older men and women who regularly consumed up to 21 drinks of wine a week were less likely than teetotalers to develop Alzheimer’s disease and other forms of dementia. Similarly, a recent 12-year, 1,488-person survey at Johns Hopkins University in Maryland suggests that regular, moderate drinkers score better over time than teetotalers do on the Mini-Mental State Examination (MMSE), a standard test for memory, reasoning, and decision making. That’s the good news. Here’s the bad news: The same studies that applaud the effects of moderate drinking on heart health are less reassuring about the relationship between alcohol and cancer: The American Cancer Society’s Cancer Prevention Study 1 shows that people who take more than two drinks a day have a higher incidence of cancer of the mouth and throat (esophagus). In addition;
  • Researchers at the University of Oklahoma say that men who drink five or more beers a day double their risk of rectal cancer.
  • American Cancer Society statistics show a higher risk of breast cancer among women who have more than three drinks a week, but newer studies suggest this effect may apply only to older women using hormone replacement therapy.

Alcohol and Brain

Alcohol is a sedative. When it reaches your brain, it slows the transmission of impulses between nerve cells that control your ability to think and move. That’s why your thinking may be fuzzy, your judgment impaired, your tongue twisted, your vision blurred, and your muscles rubbery. Do you feel a sudden urge to urinate? Alcohol reduces your brain’s production of antidiuretic hormones, chemicals that keep you from making too much urine. You may lose lots of liquid, plus vitamins and minerals. You also grow very thirsty, and your urine may smell faintly of alcohol.

This cycle continues as long as you have alcohol circulating in your blood, or in other words, until your liver can manage to produce enough ADH to metabolize all the alcohol you’ve consumed. How long is that? Most people need an hour to metabolize the amount of alcohol (1⁄2 ounce) in one drink. But that’s an average: Some people have alcohol circulating in their blood for up to three hours after taking a drink.

Rising to the surface

In your blood, alcohol raises your level of high-density lipoproteins (HDLs), although not necessarily the specific good ones that carry cholesterol out of your body. Alcohol also makes blood less likely to clot, temporarily reducing your risk of heart attack and stroke.
Alcohol makes blood vessels expand, so more warm blood flows up from the center of your body to the surface of the skin. You feel warmer for a while and, if your skin is fair, you may flush and turn pink. (Asians, who — you may remember from a few paragraphs back — tend to make less alcohol dehydrogenase than do Caucasians, often experience a characteristic flushing when they drink even small amounts of alcohol.) At the same time, tiny amounts of alcohol ooze out through your pores, and your perspiration smells of alcohol.

Taking time out for air

Entering your heart, alcohol reduces the force with which your heart muscle contracts. You pump out slightly less blood for a few minutes, blood vessels all over your body relax, and your blood pressure goes down temporarily. The contractions soon return to normal, but the blood vessels may remain relaxed and your blood pressure lower for as long as half an hour. At the same time, alcohol flows in blood from your heart through your pulmonary vein to your lungs. Now you breathe out a tiny bit of alcohol every time you exhale, and your breath smells of liquor. Then the newly oxygenated, still alcohol-laden blood flows back through the pulmonary artery to your heart, and up and out through the aorta (the major artery that carries blood out to your body).

Stopping for a short visit at the energy factory

Most of the alcohol you drink is absorbed through the duodenum (small intestine), from which it flows through a large blood vessel (the portal vein) into your liver. There, an enzyme similar to gastric ADH metabolizes the alcohol, which is converted to energy by a coenzyme called nicotinamide adenine dinucleotide (NAD). NAD is also used to convert the glucose you get from other carbohydrates to energy; while NAD is being used for alcohol, glucose conversion grinds to a halt.
The normal, healthy liver can process about 1⁄2 ounce of pure alcohol (that’s 6 to 12 ounces of beer, 5 ounces of wine, or 1 ounce of spirits) in an hour. The rest flows on to your heart.