Every so often a scientific study is published that the media gets a hold of and shouts from the rooftops until it’s common knowledge. These studies often make attractive headlines that either scare you or make you feel better about your normal everyday habits.
However, one of the most popular scientific media morsels is the idea that drinking a moderate amount of alcohol can be good for your heart.
It’s true that some studies seem to show that light to moderate alcohol consumption could be good for your heart and help you avoid dangerous heart disease. One study in 2016 found that moderate drinking seemed to lower a person’s risk of stroke.
The study also pointed out that heavy alcohol use could increase your risk of having a stroke. Alcohol has significant effects throughout your body, including in your blood. Plus, the amount of alcohol you drink makes a big difference. Learn the truth about alcohol’s effects on your blood and whether it lowers or raises your blood pressure.
When you drink alcohol, it gets into your bloodstream through your metabolism. Once it’s floating around in your blood, it filters out by your liver. Your body can’t store alcohol like it can for fats and sugars. So when you consume alcohol, your body essentially treats it like poison and prioritizes getting this foreign chemical out of your system.
Your liver can only handle so much alcohol at a time. If you drink too much alcohol, it gets past your liver and makes its way to your brain. This process ultimately determines what’s considered light to moderate drinking.
If you only drink one drink in two hours, your liver will process the majority of the alcohol, and only trace amounts will make it to your brain and other organs if any. A standard drink has been defined by the National Institute on Alcohol Abuse and Alcoholism as 12 ounces of regular beer (5 percent alcohol), eight to nine ounces of malt liquor, five ounces of wine (12 percent alcohol), and 1.5 ounces of distilled liquor.
Studies have shown that one standard drink for women and two standard drinks for men are what lead to improved heart health.
One of the reasons that alcohol is good for your heart in a moderate amount might have something to do with its anticoagulation effects. Coagulation is when blood cells clump up and form clots. Anticoagulants are often called blood thinners because they help keep your blood flowing smoothly through your veins and lower blood pressure.
Alcohol seems to have this effect when it’s taken in light to moderate doses. This can help lower your blood pressure and help you avoid heart attacks and ischemic strokes. However, it also has other negative effects.
Anticoagulants can also help blood flow faster when you’re bleeding. Thin blood and very low blood pressure can also increase your risk of a different kind of stroke. Alcohol is said to help you avoid ischemic strokes, which is a stroke caused by a blockage in an artery leading to your brain.
Hemorrhagic strokes are when an artery bursts or when a blood vessel leaks. Thin blood can flow freely out of the rupture without making it to the brain, causing damage. Still, hemorrhagic strokes are less common than ischemic strokes.
The most common danger that may come with lower blood pressure and thin blood is bleeding in surgery. Doctors tell patients to refrain from drinking alcohol in the days leading up to a surgical procedure. You may think that one or two drinks can’t hurt, but it can be deadly.
When you are in surgery, your doctors do everything they can to control bleeding while they do what they have to do. Even moderate drinking in the days before surgery can cause heavy bleeding while you’re under the knife.
In the worst cases, you can bleed out and die on the operating table. In the best cases, your heavy bleeding will obscure the work your surgeon is doing and make their job a lot harder, and the procedure needlessly dangerous.
Blood thinners, like warfarin, are used to treat hypertension. Alcohol may potentiate blood thinners, which means that it intensifies its effects. This can lead to hypotension, which can cause dizziness, lightheadedness, fainting, blurred vision, nausea, fatigue, and a lack of concentration.
Extreme hypotension can lead to confusion, a weak pulse, clammy hands, shallow breathing, and shock that can be life-threatening. If you are taking a blood thinner, you should avoid alcohol until you’ve spoken to your doctor about the dangers of mixing alcohol and your medication.
If alcohol is supposed to lower your blood pressure, why do doctors recommend limiting or cutting out alcohol when you have high blood pressure? According to a 1998 study, the anticoagulant and procoagulant effects of alcohol may depend on the quantity of alcohol you consume. In other words, light drinking can lower your blood pressure, but heavy drinking can raise it.
Dimmitt, S. B., Rakic, V., Puddey, I. B., Baker, R., Oostryck, R., Adams, M. J., . . . Beilin, L. J. (1998, January). The effects of alcohol on coagulation and fibrinolytic factors: A controlled trial. from https://www.ncbi.nlm.nih.gov/pubmed/9607117
Mayo Clinic. (2018, March 10). Low blood pressure (hypotension). from https://www.mayoclinic.org/diseases-conditions/low-blood-pressure/symptoms-causes/syc-20355465
National Institute on Alcohol Abuse and Alcoholism. (2018, December 13). What Is A Standard Drink? from https://www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/what-standard-drink
National Stroke Association. (n.d.). Hemorrhagic stroke. from https://www.stroke.org/understand-stroke/what-is-stroke/hemorrhagic-stroke/
Susanna C. Larsson, Alice Wallin, Alicja Wolk, & Hugh S. Markus. (2016, November 24). Differing association of alcohol consumption with different stroke types: A systematic review and meta-analysis. from https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0721-4