Approximately 70 million, or 1 out of every 3 American adults, have hypertension (chronic high blood pressure), a condition that can lead to heart disease, stroke, and kidney disease. Just as many adults have prehypertension, with blood pressure that is higher than normal but not yet high enough to be diagnosed with hypertension.

Coffee, because of its high caffeine content, has long been suspected of contributing to higher blood pressure. Some researchers also speculate that it isn’t the caffeine in coffee that raises blood pressure but one of any number of substances found in both caffeinated and non-caffeinated coffee.

However, numerous scientific studies published in recent years have found that that coffee is safe to drink, even for those with established heart disease or hypertension. Some researchers think coffee may even boost heart health. (Just what so many of us want to hear—coffee is a health food!) But further investigation shows that while this may be true for some people, it is not necessarily true for everyone.

Hypertension 101

Blood pressure is the force with which blood pushes against artery walls as it flows through your circulatory system. Pressure is measured in a ratio that reflects systolic pressure (when the heart beats) over diastolic pressure (between beats). The American Heart Association defines normal blood pressure as less than 120 systolic/less than 80 diastolic, or less than 120/80. A measure of 120/80 to 139/89 indicates prehypertension. A measure of 140/90, or above, indicates hypertension. When your blood pressure is high, it means your blood is applying more force than normal.

Until recently, older and high-risk patients with hypertension were advised to set a target of 130 or 140 systolic blood pressure. In 2015, the Systolic Blood Pressure Intervention Trial (SPRINT), a large, ongoing clinical trial sponsored by the National Institutes of Health, found that most older and high-risk patients benefit from a target goal of less than 120 systolic using medication combinations and lifestyle changes.

The Ups and Downs of Coffee Consumption

While some people can drink five cups of coffee with seemingly little effect, others get the shakes from anything more than a cup or two. This may depend on how long you’ve been drinking coffee, how often or how much you drink, the type of coffee consumed, or other factors, including how your body metabolizes coffee compared to someone else. According to some experts, even the expectation of drinking a cup of coffee can change the way it affects you.

While coffee has been found in some studies to have positive effects on the development of type 2 diabetes, Alzheimer’s and Parkinson’s diseases, and even some cancers, its effect on blood pressure has long been unclear, with many studies finding that any rise in pressure is temporary and unlikely to have long-term effects.

But a study published in the Journal of Hypertension in June, 2015 found that young-to-middle-age coffee drinkers with hypertension were at higher risk of developing heart problems over time. Those who drank more than three cups of coffee a day were at higher risk than those who drank one to three cups a day, but all coffee drinkers were at higher risk than those who drank no coffee at all. These researchers recommend that young to middle-age adults with hypertension reduce their coffee consumption.

“Not everyone responds adversely to caffeine,” says cardiologist William A. Tansey III, MD of Summit Medical Group in New Jersey. To find out if coffee affects your blood pressure, Dr. Tansey suggests checking your own sensitivity by taking your blood pressure before and after two or three cups. Obviously, if you are sensitive, you will see a rise in pressure.

William A. Tansey III, MD, reviewed this article.

Sources

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Understanding Blood Pressure Readings. American Heart Association website. Updated April 28, 2015. Accessed October 2, 2015.

High Blood Pressure Facts. Centers for Disease Control website. Updated February 19, 2015. Accessed October 2, 2015.

Landmark NIH Study Shows Intensive Blood Pressure Management May Save lives. National Heart, Lung and Blood Institute website. September 11, 2015. Accessed October 2, 2015.