Even just a few drinks could be affecting you in ways you’d never expect.

Once we reach middle age (roughly age 45) and beyond, we can simply look in the mirror to get ample evidence that our bodies are aging. What’s not so evident is the cascade of hidden physiological changes taking place that drastically alter how our bodies process beer, wine and liquor, creating a host of health dangers.

Important: Even if you don’t drink excessively—and imbibe no more than you ever have—there are still crucial, little-known facts everyone should have about alcohol’s effect on the body as we age.

To learn more, Bottom Line/Health recently spoke with Robert L. Doyle, MD, one of the country’s leading authorities on alcohol use.

WHAT HAPPENS WHEN WE DRINK

Research showing an association between moderate drinking—usually defined as no more than two drinks daily for men…and one for women (see box)—and lower rates of heart disease has gotten a lot of attention. But that’s only part of the story.

Alcohol is metabolized primarily by the liver, which undergoes significant change with age. This “detoxifier” is very similar to a car’s air filter—the longer it’s used, the more clogged it becomes. That’s the main reason a hangover hits us harder when we’re middle aged or older than it might have in college—and even more important, problem drinking increases our risk of developing cirrhosis and other liver diseases.

But other parts of the body also are significantly affected by alcohol…

  • Brain. Excessive drinking is just one of many cumulative “insults”—such as banging our heads—that can affect the brain. Whether you drink too much over time or on a single occasion, alcohol’s effect on your brain can lead to changes in your mood and behavior and make it more difficult to think clearly and move with coordination.
  • Muscle mass. We lose muscle mass—at an average rate of 5% for each decade after age 35. On top of that, our bodies tend to become pudgier and fat shifts to other places, such as the midsection. Combine this with the fact that many older adults are chronically dehydrated—if you get less fluid, you won’t be running to the bathroom so often!—and it sets the stage for more alcohol to build up in the bloodstream. That’s because fat does not absorb alcohol as much as muscle does, and less water means alcohol’s effects are stronger. Because women tend to have a higher fat-to-muscle ratio, they generally have higher blood-alcohol levels than men when they consume the same number of drinks.
  • Enzymes. Beginning roughly at middle age, we produce declining amounts of alcohol dehydrogenase, an enzyme that breaks down alcohol. This means that you may well get a bigger buzz from a smaller number of drinks.

THE GOOD AND THE BAD

Even though alcohol’s link to reduced heart disease risk has been widely publicized, there are negative effects that most people don’t know about.

For example…

  • Heartburn. If you have a stomach ulcer or chronic heartburn stemming from gastroesophageal reflux disease (GERD), alcohol wears away the mucous lining of the gastrointestinal tract, increasing the risk for internal bleeding. These gastrointestinal conditions (and the medications that are used to treat them) also can prevent good absorption of some nutrients from your food, increasing alcohol’s punch.
  • Pain. Using alcohol to ease a backache or any other chronic pain condition is a bad idea. It often leads to an increasing reliance on booze, which can quickly result in alcohol abuse.
  • Stroke. When it comes to stroke, the research is mixed. One drink per day may lower stroke risk, but drinking more than one to two drinks a day may increase your chances of having a stroke.
  • Memory loss. New research shows that middle-aged men who consumed more than 2.5 drinks each day showed reductions in memory and executive function (decision-making ability) between 1.5 and six years sooner than those who had fewer drinks daily. The research also suggested a faster cognitive decline in women who drank heavily, but the results weren’t statistically significant.
  • Cancer. Excessive drinking has been linked to several types of cancer, such as malignancies of the mouth, esophagus, liver and colon. Women who drink even moderate amounts (one drink daily) have a slightly higher risk for breast cancer than nondrinkers. In fact, there is a 10% to 12% higher risk for breast cancer associated with each drink per day.

ALCOHOL AND MEDICATION

It’s no secret that people tend to take more over-the-counter and prescription medications as they age. Many of these drugs—and herbal remedies—are metabolized by the same liver enzymes needed to process alcohol.

Mixing alcohol with medications such as blood thinners can cause gastrointestinal bleeding. And heartburn medications, such as cimetidine (Tagamet) and ranitidine (Zantac), interfere with alcohol metabolism, allowing blood-alcohol levels to spike. Other drugs that interact with alcohol include cold and flu medications, pain relievers, antidepressants and sleep aids.

For a list of medications and herbs that interact with alcohol, go to the Web site of the National Institute on Alcohol Abuse and Alcoholism, NIAAA.NIH.gov (under the “Publications” tab, click on “Harmful Interactions: Mixing Alcohol with Medicines”).

Takeaway: Because alcohol affects the body in such complex ways, it’s always wise to talk to your doctor honestly about your drinking habits and how alcohol could affect the medications you take…any chronic health conditions you may have…and/or your risk factors for disease. In general, the older we get, the less alcohol we should drink.