Several older studies suggest that taking in one glass of wine per day for women or two glasses of wine per day for men is associated with reduced risk for a heart attack. However, a review of 107 studies involving more than 4.8 million participants found no reduction in death rate for people who drank fewer than two drinks (25 grams) of alcohol per day, and there was an increase in risk of death among female drinkers who drank 25 or more grams per day and male drinkers who drank 45 or more grams per day (JAMA Netw Open, Mar 31, 2023;6(3):e236185).
Potential Flaws in Studies Suggesting that Light Drinking Reduces Heart Attack Risk
For a study to show that alcohol reduces heart attack risk, it must compare a test group of drinkers with a control group of non-drinkers. The studies that appear to show health benefits from low doses of alcohol may be due to using faulty control groups. Moderate drinkers have been shown to be healthier than non-drinkers because they are usually more highly educated, have more money, are more physically active, are more likely to have health insurance and to eat more vegetables (J Stud Alcohol Drugs, 2016 Mar;77(2):185-98). More significantly, the non-drinking control groups in these studies have included people who gave up alcohol on their doctors’ instructions because they have health problems: high blood pressure, diabetes, high cholesterol, or diseases of the heart, kidney, liver or lungs and so forth, as well as recovering alcoholics. These unhealthy people will have higher death rates.
A study with a 20-year follow-up of 4,028 18-to-64-year-old adults found that when the people who had stopped drinking for medical reasons were removed from the control group, moderate drinkers did not live longer than non-drinkers (PLoS Medicine, Nov 2, 2021;18(11):e1003819). An analysis of 45 earlier studies showed that those associating moderate drinking of alcohol with reduced heart attacks rates needed better control groups (J Stud Alcohol and Drugs, May 2017;78(3):394-403).
No Health Benefits from Low Doses of Alcohol
A recent review of seven studies covering more than 19,000 adults found that taking one alcoholic drink a day for more than four years is associated with a rise in blood pressure, even if these people previously had normal blood pressure (Hypertension, July 31, 2023).
The World Heart Federation reported that taking one drink a day did not help to prevent heart attacks (Clinical Nutrition, Feb 1, 2022;41(2):348-355). A study of 371,463 individuals found that no amount of alcohol helps to prevent heart disease, and the more you drink, the greater your chance of suffering a heart attack (JAMA Netw Open, March 2022;5(3):e223849).
People who take just one drink a day may be at increased risk for heart disease (J American College of Cardiology, December 5, 2016), and an enlarged upper heart and irregular heartbeats that can cause clots and strokes (J Am Heart Assoc, Sep 14, 2016;5:e004060; J Am Coll Cardiol, 2016;68(23):2567-2576). Binge drinking, defined as having five or more drinks in a single bout, increased risks even more. Data from six studies including more than 12,500 cases of atrial fibrillation (an abnormally fast heartbeat that can cause clots, strokes and heart failure) showed that each additional drink per day of any type of alcohol boosted risk of irregular heartbeat by eight percent (J Am Coll Card, July 14, 2014). Many other studies have associated drinking alcohol with atrial fibrillation, high blood pressure, heart failure and strokes. Association is not cause, but I believe that these studies give reason for caution.
Alcohol intake has been linked to increased heart rate, high blood pressure, weakened heart muscle and irregular heartbeats, all of which can increase the risk of heart attacks and strokes (Alcohol Clin Exp Res, Dec 2015;39(12):2334–2344). Drinking any amount of alcohol is associated with increased risk for irregular heartbeats or atrial fibrillation (European Heart J, March 21, 2021;42(12):1170-1177). A study of 79,000 Swedish adults, aged 45-83, followed for up to 12 years, showed that those who drank any amount of wine or liquor daily were at increased risk for atrial fibrillation (J American College of Cardiology, July 14, 2014).
My Recommendations
Many early studies suggested that it is safe for women to take up to one drink per day and for men to take up to two drinks per day. Almost 30 percent of North Americans take in one or more drinks per day. Recent studies suggest that no amount of alcohol may be “safe” or beneficial. Whatever you decide about your own consumption of alcohol, do not base your decision on information from the alcoholic beverage industry. Occasional drinking probably will not harm you, but drinking alcohol daily may increase your risk for heart attacks and strokes.
