Is Moderate Drinking Good or Bad for You?

For decades, Americans got the message that drinking in moderation might be good for us. While it was clear that heavy or binge drinking carried health risks, the conventional wisdom held that there was a “safe” middle ground when it came to alcohol.

But more recent research on alcohol’s effect on heart disease, cancer, and the brain has prompted changes from major health organizations and societies, leaving many of us wondering if our drinking habits are based on outdated science.

The big question: Is regularly drinking wine or enjoying a nightly cocktail a good thing, or are we hurting our health?

If you’re fuzzy about how much it’s okay to drink, it’s understandable.

Part of the confusion comes from the science itself. Alcohol has complex and sometimes competing effects on the body, and most of what researchers know comes from observational studies that can’t fully separate the effects of drinking from those of other lifestyle factors, says Ned Calonge, MD, MPH, professor of epidemiology at the Colorado School of Public Health in Aurora and the committee chair on the National Academies’ report on moderate alcohol consumption.

But there is consensus that drinking beyond moderate levels poses significant health risks.

What Is Moderate Drinking?

Most experts define moderate drinking as one drink a day for women and no more than two for men.

“Some people will respond to the idea of drinking only one drink in 24 hours by saying ‘I can’t just have one drink,’ or asking, ‘Then, what’s the point?’” says Gregory Marcus, MD, cardiologist, professor of medicine, and researcher at UCSF Health in San Francisco and the vice chair of the American Heart Association’s scientific statement on alcohol use.

“Those are individuals for whom drinking no alcohol is almost certainly better for their health than drinking any,” says Dr. Marcus.

“In hindsight, there was probably too much confidence that red wine was beneficial for the heart, but the pendulum has now swung too far in the other direction, where moderate alcohol use is often assumed to be harmful despite the available evidence,” says Marcus.

“Uncertainty remains about the true cardiovascular risk of drinking lightly such as one to two drinks a day,” according to the authors of the AHA scientific statement.

Alcohol can make blood less likely to clot, which might reduce the risk of heart attacks and some types of stroke, but that same effect can increase the risk of dangerous bleeding, he says.

Researchers believe moderate drinkers may have had lower heart risks because of brain changes — specifically reductions in stress signaling. However, because of alcohol’s overall impact on the health, the authors did not recommend drinking as a preventative strategy against heart attack and stroke.

Red Wine and Resveratrol

Some basic science research has suggested that certain components of red wine might be beneficial, says Marcus. In particular, antioxidants called polyphenols, including resveratrol, have been studied for their potential to raise “good” HDL cholesterol, protect blood vessels, and reduce blood clotting.

Across multiple large studies, scientists have tied alcohol to an increased risk of several cancers, says Chinmay Jani, MD, chief fellow of hematology and oncology and a researcher on alcohol and cancer risk at the University of Miami–Jackson Health System in Florida.

The link between drinking and cancer is driven by many mechanisms in the body, says Dr. Jani, including the cancer-causing effects of acetaldehyde (a toxic byproduct of alcohol that damages DNA), along with oxidative stress, inflammation, and hormonal changes.

The odds of developing cancer increase as people drink more, especially for those with other risk factors, such as a family history of cancer or certain genetic traits, he says.

“From a prevention standpoint, the takeaway is simple: Drinking less alcohol lowers cancer risk,” says Jani.

• Breast Cancer In data collected from 118 studies, breast cancer risk was 4 percent higher for light drinkers and 23 percent higher for moderate drinkers compared with nondrinkers.
• Mouth and Throat Cancer Moderate drinkers raise their risk of mouth cancer by 80 percent and throat cancer by 40 percent versus nondrinkers.
• Esophageal Cancer When compared with no alcohol consumption, the risk was found to increase by 30 percent for light drinkers.
• Colon Cancer Moderate drinking increases the risk of colon or rectal cancer by an estimated 20 percent.

While many people depend on a nightly drink or two to help them fall asleep, drinking keeps you from getting the kind of sleep your brain needs to feel rested, says Stephen Holt, MD, an internal medicine doctor and addiction medicine specialist at Yale Medicine in New Haven, Connecticut.

When alcohol acts as a sedative, it can knock you out without allowing enough restorative or REM sleep and leave you feeling tired or foggy, even after a full night of sleep, he says.

“Over time, alcohol can also disrupt the body’s natural circadian rhythm by interfering with normal melatonin release, throwing off the brain’s internal clock and contributing to a cycle of poor quality sleep that affects energy, mood, and overall health,” says Dr. Holt.

While the definition of moderate drinking is straightforward, having one or two drinks doesn’t affect everyone’s health equally.

Factors that may influence your risk include:

• Genetics People of East Asian descent with the genetic variation ALDH2 have trouble metabolizing alcohol, making them at higher risk of alcohol-related cancer and heart issues, even if they are moderate drinkers.

  [15]

• Chronic Conditions Being at risk for or having chronic diseases such as type 2 diabetes can make moderate drinking riskier because of its effects on blood sugar and weight. Excess calories from alcohol are stored in the liver as fat.

  [16]

• Being Female Women metabolize alcohol differently from men, which is one reason why moderate drinking for females is just one drink per day.

  [15]

• NSAIDs, such as Advil
• Acetaminophen, such as Tylenol
• Pain medications such as opioids
• Medications taken for heart issues, including warfarin and some beta blockers
• Drugs for anxiety and sleep, including benzodiazepines and “Z-drugs” like Lunesta (eszopiclone), Sonata (zaleplon), and Ambien (zolpidem)

Despite some potential heart benefits, even moderate drinking is associated with increased risks for other health outcomes, including certain cancers, making it difficult to weigh alcohol’s overall impact on health, says Marcus.

Experts agree that any evidence of benefit isn’t strong enough to suggest that people who don’t drink should start drinking — especially given the clear risks of heavy drinking.

While our understanding of the risks and benefits of moderate drinking continue to evolve, it’s mostly based on associations, not cause and effect. That’s because it would be nearly impossible to do the highest quality research in a study comparing drinkers to nondrinkers for years or even decades, says Calonge.

• Moderate drinking is not risk-free. While some studies suggest small amounts of alcohol may be linked to lower risks of certain heart-related outcomes, alcohol is also tied to increased cancer risk.
• Cutting back on drinking is one of the most reliable ways to lower alcohol-related cancer risk.
• If you don’t drink, don’t start: There’s not enough evidence of benefit to outweigh the risks. If you do drink, staying within recommended limits, avoiding binge drinking, and prioritizing proven health behaviors can help reduce overall risk.