Studies have shown that alcohol can have a good or bad impact depending on how much you drink.
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Should you enjoy that glass of wine with dinner? Is it okay to relax with a cold beer? When it comes to your heart health, the answer is not clear. The existing research is quite conflicting — some studies say alcohol improves heart health, while others imply the reverse.
So, what's the truth?
"It comes down to moderation," says Dr. J. Michael Gaziano, a preventive cardiologist with Harvard-affiliated Brigham and Women's Hospital's Division of Aging and VA Boston. "A safe amount — about one drink per day — may support a healthy heart and lower your risk of heart disease, while too much can be damaging."
What is a "drink"?
Moderate alcohol intake is associated with some heart benefits, but how much is considered moderate? A safe amount for men is no more than a drink per day, says Dr. J. Michael Gaziano, a preventive cardiologist with Harvard-affiliated Brigham and Women's Hospital's Division of Aging and VA Boston. Of course, alcohol content can vary with the type and size of drink. In the United States, a standard drink is about 14 grams of pure alcohol, which equates to any one of these:
To get a more accurate analysis of your drink in terms of alcohol content per serving size, use this drink calculator from the National Institutes of Health: www.health.harvard.edu/size.
What the evidence shows
The problem with most alcohol-related research is that it consists almost entirely of observational studies that only show an association. "No large-scale trials have provided clear evidence on cause and effect," says Dr. Gaziano. "Therefore, you can't say for certain whether alcohol plays an essential role in reducing common heart disease risk factors like high cholesterol levels and high blood pressure."
So far, the strongest evidence has shown that alcohol can increase levels of HDL (good) cholesterol. HDL works to keep LDL (bad) cholesterol from clogging your arteries by moving it to the liver, where it's broken down and removed from the body. Many studies have found that the combination of high HDL and low LDL levels protects against heart attacks and stroke.
"However, this is not the most important factor in preventing heart disease, and there are other ways to increase HDL than drinking alcohol, such as regular exercise," says Dr. Gaziano.
Does the source of the alcohol matter? Not really. Your body reacts to alcohol the same whether it's from beer, wine, or spirits. While some research has touted the benefits of drinking red wine to fight heart disease, the findings tend to point to the wine's high levels of resveratrol (a plant chemical that reduces inflammation) and not its alcohol content as the main reason.
The key factor in alcohol's effect on heart health appears to be quantity. While moderate amounts of alcohol may offer some heart benefits, too much can have the opposite effect. For instance, the more alcohol you drink at one time, the higher your heart rate gets, according to research from the European Society of Cardiology.
It's thought that too much alcohol creates an imbalance between the sympathetic (fight or flight) and parasympathetic (rest and digest) nervous systems, which raises your heart rate, according to the researchers. A sudden spike in heart rate is potentially dangerous to people with heart conditions, as it could trigger arrhythmias (irregular heartbeats).
Focus on moderation
The definition of moderate drinking may mean less alcohol than has previously been promoted, according to a study in the April 14, 2018, issue of The Lancet that looked at the drinking habits of almost 600,000 people without heart disease.
People who had 10 or more drinks per week died one to two years earlier compared with those who drank five drinks or fewer per week. Having 18 drinks or more per week cut life expectancy by four to five years.
Because of the lack of consistent data, the takeaway message here is to focus on moderation and avoid excessive and binge drinking. "You can't put alcohol in same category as taking blood pressure or cholesterol medicine in terms of protecting against heart disease," says Dr. Gaziano. "However, when combined with not smoking, eating a healthy diet, exercising, and managing your weight, moderate alcohol intake can be part of a heathy lifestyle."
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