Alcohol can thin your blood, because it prevents blood cells from sticking together and forming clots. This may lower your risk for the type of strokes caused by blockages in blood vessels.
Yet because of this effect, drinking alcohol could potentially increase your risk for the bleeding type of strokes — especially when you drink it in large quantities. For men, this means more than two drinks a day. For women, this is more than one drink a day. Alcohol use — especially in excess — can also pose other risks to your health.
Keep reading to learn more about this blood-thinning effect, how alcohol interacts with blood-thinning medications, and more.
When you’re injured, blood cells called platelets rush to the injury site. These cells are sticky, and they clump together. Platelets also release proteins called clotting factors that form a plug to close the hole.
Clotting is beneficial when you’re injured. But sometimes, a blood clot can form in — or travel to — an artery that supplies your heart or brain with oxygen-rich blood. Clotting of the blood is called thrombosis.
Alcohol interferes with the clotting process in a couple of ways:
- It reduces the number of platelets in the blood, in part by interfering with blood cell production in the bone marrow.
- It makes the platelets you do have less sticky.
Drinking a glass or two of wine each day might reduce your risk for heart disease and strokes caused by blockages in blood vessels (ischemic strokes) in much the same way that taking a daily aspirin can prevent strokes.
In people who drink moderately, the effect of alcohol on platelets is short-lived.
According to the Mayo Clinic, moderate drinking is classified as follows:
- For women of all ages: up to one drink per day
- For men age 65 or older: up to one drink per day
- For men younger than age 65: up to two drinks per day
Examples of one drink include:
- a 12-ounce beer
- a 5-ounce glass of wine
- 1.5 fluid ounces, or a shot, of liquor
But in people who drink heavily, there can be a rebound effect in which the bleeding risk increases, even after they’ve stopped drinking. Exceeding the recommended guidelines above is considered heavy drinking.
No. Blood thinners are drugs your doctor prescribes to prevent blood clots that can cause a heart attack or stroke. If your doctor has prescribed one of these medicines, it’s because you have heart disease or another condition that increases your risk for clots.
Alcohol isn’t safe to use as a blood thinner. Not only can it increase your chance of having a bleeding stroke, but in large quantities it also puts you at greater risk for:
- injuries due to falls, motor vehicle accidents, and other types of accidents
- sexually transmitted diseases (STDs) due to risky sexual behaviors
- liver disease
- stomach bleeding
- cancers of the breast, mouth, throat, liver, colon, and esophagus
- birth defects and miscarriage when used during pregnancy
- alcohol dependence or alcoholism
Ask your doctor if it’s safe for you to drink alcohol while taking blood thinners. Both alcohol and blood thinners like warfarin (Coumadin) thin your blood. Taking both together could compound the anticoagulant effect and increase your risk of bleeding.
Alcohol might also slow down the rate at which your body breaks down and removes the blood-thinning drug. This can lead to a dangerous buildup of the drug in your body.
If you do drink alcohol while on blood thinners, do so in moderation. That means one drink a day for women and men age 65 and older. For men under age 65, up to two drinks a day is considered moderate.
Drinking alcohol in moderation may have a protective effect on your blood vessels. Some research finds that alcohol increases levels of high-density lipoproteins (HDL, aka “good cholesterol”). This healthy type of cholesterol helps protect your arteries and prevent the blood clots that can lead to heart attacks and strokes.
Yet there are other, less risky ways to protect your arteries — for example, by eating a plant-based diet and exercising. The American Heart Association doesn’t recommend drinking alcohol solely to protect your blood vessels and improve your circulation.
If you’re going to drink alcohol, do so in moderation. Have no more than one or two drinks daily.
One drink is equal to:
- 12 ounces of beer
- 5 ounces of wine
- 1.5 ounces of vodka, rum, or other liquor
When it comes to the health of your blood vessels, have a conversation with your doctor. Ask if you’re at risk for heart disease or stroke. If so, find out what steps you can take to lower those risks.