By Beth Israel Deaconess Medical Center Correspondent
Before you raise your glass, you should be aware of some important ways that alcohol affects your heart. For example, did you know that:
- In the hour after alcohol consumption, a person’s risk of stroke and heart attack doubles?
- Potentially dangerous arrhythmias can result from too much holiday cheer, a condition that has come to be known as Holiday Heart Syndrome?
- Moderate alcohol consumption on most days of the week may help guard against heart disease?
These are some of the key discoveries that have emerged from the Cardiovascular Epidemiology Research Unit (CVERU) at Beth Israel Deaconess Medical Center (BIDMC). In conjunction with the Harvard T.H. Chan School of Public Health (HSPH), the CVERU conducts observational and experimental research to identify risk factors for heart disease. Under the direction of Murray Mittleman, MD, DrPH, the CVERU is nationally recognized for its many studies examining how alcohol consumption impacts cardiac health.
“Whether alcohol protects us from heart disease or promotes heart disease depends on a number of key factors,” says Mittleman, who is also a preventive cardiologist in BIDMC’s CardioVascular Institute and Professor of Epidemiology at HSPH. “These include the amount of alcohol consumed and the frequency of consumption.”
Either way, the take-home message is the same: If you do drink, do so in moderation. That means no more than one drink per day for women and no more than two drinks per day for men, according to guidelines from the American Heart Association. A drink is defined as 12 ounces of beer, four ounces of wine, 1.5 ounces of 80-proof spirits, or one ounce of 100-proof spirits.
Five facts to keep you healthy:
- The Not-So-Happy Hour
A large study by BIDMC researchers published earlier this year reported that in the hour following alcohol consumption, a person’s risk of having a stroke or heart attack actually doubles. Led by Elizabeth Mostofsky, ScD, MPH, a scientist in BIDMC’s CVERU, the comprehensive meta-analysis (a study of studies) analyzed data from 23 studies conducted between 1966 and 2015, involving a total of 30,000 participants. The goal was to better understand a person’s risk of having a stroke or heart attack in the hours and days after consuming alcohol.
“It’s a complicated subject,” says Mostofsky, who is also an instructor at HSPH. “The fact is that alcohol has complex physiological effects that can result in both higher cardiovascular risk and lower cardiovascular risk. We found that any alcohol consumption raised a person’s risk of a heart attack or stroke approximately two-fold within the hour following consumption compared to other times. After 24 hours, though, only heavy alcohol intake conferred a continued heightened risk. “
Immediately following alcohol intake, heart rate increases, blood pressure rises and blood platelets become stickier. This may increase the risk of heart attack and stroke. But over time, regularly drinking small amounts of alcohol appears to lower cardiovascular risk by increasing levels of high-density lipoprotein (HDL) cholesterol, the so-called “good cholesterol,” while also reducing a person’s tendency to form blood clots.
“Based on our results, it is possible that the brief risks we see right after drinking alcohol are outweighed by the health benefits of regularly drinking modest amounts of alcohol,” says Mostofsky.
- Holiday Heart Syndrome
You may associate the term “binge drinking” with a college fraternity party, but it actually refers to any episode of excessive drinking. This is defined by the U.S. Office of Disease Prevention and Health Promotion’s 2015 Dietary Guidelines as 15 drinks or more per week for men and eight drinks or more per week for women.
One of the greatest risks develops when people who don’t usually drink at all find themselves celebrating at parties or “binge drinking” while on vacation, a problem that was first identified almost 40 years ago and is now often referred to as “holiday heart syndrome.”
A BIDMC study of both men and women of an average age 50, found that heavy drinking — 35 or more drinks per week — led to a 45 percent increase in men’s risk of developing atrial fibrillation, a dangerous type of arrhythmia and a leading risk factor for stroke.
In cases of atrial fibrillation, the heart’s upper (atrial) chambers do not adequately contract, creating a situation in which blood can collect and clot. If a blood clot travels to the brain, it can cause a stroke.
According to the American Heart Association, atrial fibrillation is responsible for approximately 15 to 20 percent of all strokes.
In the BIDMC study, the researchers found that the risk of developing atrial fibrillation begins to increase at about four drinks per day, and clearly goes up at five drinks a day.
“This would seem to confirm what has long been suspected regarding periods of heavier-than-normal alcohol consumption, such as over the holidays or during vacations,” says Mittleman.
“Consuming large amounts of alcohol at once may result in both a sharply higher immediate risk and a higher long-term risk, but habitual moderate alcohol consumption has been shown to lower the risk of heart attacks and strokes,” adds Mostofsky.
- A Drink a Day May Keep Heart Disease at Bay
What you drink — beer, wine or spirits — isn’t nearly as important as how frequently you drink.
An important study by researchers at BIDMC and HSPH published in The New England Journal of Medicine tracked the drinking habits of nearly 40,000 men over a 12-year period and showed that men who drank moderate amounts of alcoholic beverages three or four times a week had a 30 to 35 percent reduced risk of heart attack compared with nondrinkers.
The study showed that having seven drinks on a single occasion and then not drinking the rest of the week isn’t the equivalent of having one drink a day: The weekly total may be the same, but the health implications are vastly different.
Furthermore, among men between the ages of 40 and 75, moderate drinking — no more than two drinks a day — may be better for heart health than not drinking at all.
These findings are in keeping with Mostofsky’s research.
“In our study on the acute effects of alcohol on the risk of heart attacks, we found that among participants who did not drink alcohol daily, there was a 3.3-fold higher risk of heart attacks in the hour after consumption, but the higher rate was not apparent for daily drinkers,” says Mostofsky. “It may be that habitual alcohol intake affects enzymes that metabolize alcohol, resulting in a lowered physiological response to each drink.”
“We know that drinking the same amount per week — but over the course of fewer days — is harmful. So, modest alcohol consumption appears to be more protective than either heavy drinking or no drinking at all. Once again, we see that the people who regularly drink small amounts of alcohol have a lower cardiovascular risk,” adds Mittleman.
- Benefits and Risks Can Change Over Time
According to the HSPH, in general, risks of alcohol consumption exceed benefits until middle age, when cardiovascular disease begins to account for an increasingly large share of disease. In other words, for a 30-year-old man, the increased risk of alcohol-related accidents likely outweighs the possible heart-related benefits of moderate alcohol consumption.
But for a 60-year-old man, a drink or two per day may offer protection against heart disease that is likely to outweigh potential harm (assuming he isn’t prone to alcoholism).
- Alcohol Can Indirectly Impact Your Heart
Remember that even moderate drinking affects your body in other ways that can indirectly impact cardiac health. For example, alcohol can disrupt sleep. It can interact in potentially dangerous ways with a variety of medications, including acetaminophen and other painkillers, antidepressants, and sedatives.
And, don’t forget, alcoholic beverages contain an average of about 125 calories, according to the National Institute on Alcohol Abuse and Addiction (NIAAA). When you add up the additional calories found in many festive cocktails, the chance of adding extra pounds grows, too.
Above content provided by Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted February 2017