• Alcohol is the most consumed drug worldwide and may have some cardioprotective effects.
• The AHA statement on alcohol defines moderate drinking as: one or less drinks per day for women and two or less per day for men (in the absence of binge drinking).
• One drink is defined as 12 oz of regular beer, 5 oz of wine (12% alcohol), and 1.5 oz of 80-proof spirits, all equivalent to about 15 g of alcohol.

When it comes to the purported health protective benefits of moderate alcohol consumption, the scientific world is divided into believers and skeptics (and there are abundant data to support both points of view). The story of alcohol and health benefits or health risks is based on “just the right amount” — not too little and not too much.

“Here’s to your health”

The studies that support alcohol’s health benefits are for the most part based on observational and not randomized controlled trials -this degree of evidence while not at the highest level still has relevance. The effect of moderate alcohol on cardiac events is surprisingly strong and consistent with many observational studies finding from 25 to 40 percent reduction in cardiovascular risk. More than 100 prospective studies, in fact, support health benefits of moderate drinking with a decreased risk of heart attack, ‘brain attack” (stroke), peripheral vascular disease, sudden cardiac death, and death from all cardiovascular causes.

• The Health Professionals Follow-up Study, for example, demonstrated the benefit of alcohol ingestion on at least three or four days a week was associated with a 30-35% lower risk for heart attacks in nearly 40,000 men followed over a 12-year period. This large study for the first time, strongly suggested that routine consumption of alcoholic beverages is key. (Mukamal, KJ, et al. Roles of Drinking Pattern and Type of Alcohol Consumed in Coronary Heart Disease in Men. N Engl J Med 2003; 348:109-118).

Other studies used so-called surrogate findings that include alcohol’s association with reductions in blood coagulation, increases in good cholesterol or HDL-cholesterol and its anti-inflammatory effects such as lowering C-reactive protein (hs-CRP) levels. Often not mentioned when it comes to alcohol’s health benefits is the simple enjoyment of a great glass of wine accompanying a good meal. On a final note what about the unique benefits of red wine? Red wine’s heart protective effects are actually no different than those possible with white wine or other alcoholic beverages (Booyse FM, et al. Mechanism by which alcohol and wine polyphenols affect coronary heart disease risk. Ann Epidemiol. 2007; 17:S24–31.)

Alcohol’s darker side

The 2014 World Cancer Report, issued by the World Health Organization’s International Agency for Research on Cancer, suggests that no amount of alcohol is safe at least when it comes to cancer risk. Nevertheless, the overwhelming scientific evidence does show that light-to-moderate consumption of alcohol not only reduces overall mortality but is usually not associated with an increased risk of cancer. There are studies however, that raise concerns in women for breast cancer.

• A combined analysis (meta-analysis) involving more than 320,000 women, found that having two or more drinks a day increased the chances of developing breast cancer as much as 41 percent. That means an increase from the average lifetime breast cancer rate of about 12.7 of every 100 women in the US to about 17-18 of every 100 women developing breast cancer over a lifetime. (Smith-Warner SA, , et al. Alcohol and breast cancer in women: a pooled analysis of cohort studies. JAMA. 1998; 279:535–40)

Problem drinking and too much alcohol can of course be a health risk and an important societal concern. Alcohol can cause liver inflammation (hepatitis), liver scarring (cirrhosis), stomach ulcers, malnutrition, and dementia. It is non-alcoholic fatty liver disease -related to the world-wide epidemic of obesity and diabetes and not alcohol that will account for the majority of cirrhosis cases by 2020.

According to the National Institute on Alcohol Abuse and Alcoholism more than 18 million Americans meet standard criteria for alcohol abuse or alcoholism. More than 16,000 people die each year in automobile accidents in which alcohol is involved and alcohol plays a role in about of one out of three cases of violent crime.

Balance and moderation with alcohol and life is obvious. There are some people who should not drink any alcohol, including:

• Younger than age 21.
• Pregnant or may be pregnant.
• Driving, planning to drive, or participating in other activities requiring skill, coordination, and alertness.
• Taking certain prescription or over-the-counter medications that can interact with alcohol.
• Suffering from certain medical conditions.
• Recovering from alcoholism or are unable to control the amount they drink.
• People with poorly controlled blood pressure (hypertension) may experience worsened BP control with more than moderate alcohol ingestion.

Some other considerations before you drink alcohol: remember there are calories associated with alcohol and those with diabetes (or prediabetes) need to be wary of more than an occasional alcoholic beverage. For those with diabetes drinking alcohol on an empty stomach may causes “hypoglycemia” or low blood sugar since alcohol can stimulate insulin release and lower blood sugar to dangerous levels. Too much alcohol on the other hand can add to weight and actually worsen diabetes control. For those with very high triglyceride levels even one or two drinks may cause dramatic and even dangerous worsening of  triglyceride levels and precipitate a serious condition called pancreatitis.

Alcohol and atrial fibrillation

A 2014 study of nearly 80,000 adults followed for up to 12 years through national registries in Sweden (Journal of the American College of Cardiology) confirmed previous research of an association between high alcohol consumption defined as greater than three drinks per day or binge drinking on the risk of atrial fibrillation. Atrial fibrillation (AF) is important since this cardiac electrical problem is the most common “serious” heart rhythm abnormality in people over the age of 65 years of age. Untreated atrial fibrillation doubles the risk of heart-related death and causes a 4–5-fold increased risk for stroke. AF is also related to risk of heart failure and dementia.suggests that even moderate alcohol intake for those at risk for this common electrical arrhythmia may be a concern. Both acute “binge” and chronic alcohol use have been known to be associated with cardiac arrhythmias, and in particular atrial fibrillation.

• Previous studies had not reported findings on moderate drinking of wine and liquor defined as one to three drinks per day. The latest study has for the first time showed a clear association of an increased atrial fibrillation risk with even moderate drinking. For those at risk for AF it is important to limit alcohol to 1-2 drinks.

Alcohol and medications

Alcohol can have other more common serious adverse effects when mixed with medications. This is important since according to data from the Centers for Disease Control and Prevention, nearly 50% of Americans used at least one prescription in the last 30 days. Some important alcohol-drug interactions are discussed below:

• Antihstamines, anti-anxiety, anti-depressants, sleeping pills and narcotics can all have increased sedative effects when mixed with alcohol and this is especially important for those who drive. Every day, 28 people in the United States die in motor vehicle crashes that involve an alcohol-impaired driver. This amounts to one death every 53 minutes.
• A chemical called tyramine, found in some beers and wine, may interact with a class of antidepressant drugs called monoamine oxidase inhibitors (MAO-inhibitors). This interaction may precipitate  very dangerous spikes in blood pressure called hypertensive crisis and this can be life-threatening.
• Chronic alcohol abuse can alter how many drugs are metabolized and in some cases decrease a medication effectiveness. This may require much higher dosing of a medication for it to be effective. The doses of the common anesthetic called propofol (Diprivan) may for example, need to be markedly increased in individuals with chronic alcohol consumption.  The same can occur with chronic alcohol consumption and the blood-thinner (anticoagulant) drug called warfarin (Coumadin). Chronic alcohol consumption can reduces this drug’s effect and require higher doses to get the desired benefit. On the other hand, acute or binge alcohol consumption can lead to dangerous increases in warfarin’s anticoagulant effect and increase the risk for life-threatening hemorrhages.
• Chronic alcoholics are at much higher risk for liver failure related to the over the counter pain killer Tylenol (acetamenophen toxicity) and at much lower doses. Chronic alcoholics must restrict Tylenol to  less than 4 grams per day and chronic alcohol consumption added to some common anti-inflammatory drugs like: Celebrex, ibuprofen (Motrin),  naproxen (Aleve) to name a view, can increase the risk for stomach ulcers and bleeding.
• Metronidazole (Flagyl) is an antibiotic often used to treat infections and stomach ulcers and an alcohol interaction can be very disturbing. Drinking even a small amount of alcohol while taking Flagyl can cause severe nausea and vomiting, flushing, and fast heartbeat (tachycardia). The reaction has been described as being similar to the effects of Antabuse, a drug that treats alcoholism by causing patients to become very sick when they drink. Individuals must avoid alcohol or alcohol-containing drugs while taking metronidazole and for at least 1-2 days after stopping the drug.
• Acute alcohol consumption can decrease the blood levels of important anti-tuberculosis medications (isoniazid and rifampin) and diminish efficacy with the possibility of treatment failure.
• Anti-diabetic medications to help lower blood sugar levels in patients with diabetes when taken with alcohol can have variable effects with occasional serious drops in blood sugar called hypoglycemia. Acute alcohol consumption prolongs, and chronic alcohol consumption decreases, the availability of an older diabetic medication called tolbutamide (Orinase).
• Acute alcohol consumption enhances some of blood pressure-lowering drug effects and may increase the chance of dizziness or fainting.

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Goldberg IJ, et al. AHA Science Advisory: Wine and your heart: a science advisory for healthcare professionals from the Nutrition Committee, Council on Epidemiology and Prevention, and Council on Cardiovascular Nursing of the American Heart Association. Circulation. 2001; 103:472–5.

Centers for Disease Control and Prevention (CDC). Alcohol-Related Disease Impact (ARDI). Atlanta, GA: CDC.

Department of Transportation (US), National Highway Traffic Safety Administration (NHTSA). Traffic Safety Facts 2014 data: alcohol-impaired driving. Washington, DC: NHTSA; 2015 [cited 2016 Feb 5]