A woman takes a blood pressure reading for an older black woman.

As many as 3 in 4 black adults may develop high blood pressure by age 55, according to an article published Wednesday in the Journal of the American Heart Association. That’s compared with about 55 percent of white men and 40 percent of white women the same age.

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The new calculations are based on guidelines released last year by the American Heart Association and the American College of Cardiology, which say those with a systolic blood pressure of at least 130 millimeters of mercury (top number) and a diastolic blood pressure of at least 80 (bottom number) should be considered hypertensive. The previous cutoff was 140 mmHg systolic and 90 mmHg diastolic.  (For more on how to make sense of the new guidelines, see our 2017 article.)

It has long been known that high blood pressure is more common and often more severe in African-Americans, and the latest numbers confirm the extent of that imbalance.

“Hypertension is something that can develop pretty early, and there’s a big racial disparity, where blacks tend to develop hypertension at an earlier age and at a quicker rate than whites do,” says study author S. Justin Thomas, Ph.D., an assistant professor of psychiatry at the University of Alabama at Birmingham.

Here’s what you need to know about the new research, and how anyone can start getting their blood pressure under control.

What the New Findings Mean

Thomas’ team analyzed data from 3,890 black and white people who had a baseline health examination in 1985 or 1986, when they were between ages 18 and 30, and who received follow-up exams over a period of 30 years.

By age 55, 75.5 percent of black men and 75.7 percent of black women in the study had developed hypertension. By contrast, 54.5 percent of white men and 40 percent of white women had high blood pressure by the same age.

The study also found that even black young adults whose blood pressure was in the lowest category (below 110/70 mmHg) in the study’s initial examinations would go on to develop hypertension at higher rates than whites.

That’s significant because some previous evidence has suggested that the racial disparities in hypertension that show up later in life actually begin in childhood, says Keith C. Ferdinand, M.D., professor of medicine at the Tulane University School of Medicine and the Tulane Heart and Vascular Institute in New Orleans, who was not involved in this study.

While that’s still probably the case for some people, Ferdinand says, the new study shows that even when black and white young people start out with similar blood pressure levels, black adults go on to develop hypertension at higher rates than white adults.

The reasons for this aren’t perfectly clear to scientists, Ferdinand says. But while there may be some genetic risk factors at play, he says, “the overwhelming reasons for the increased burden of hypertension are probably related to a mixture of lifestyle and behavioral activities such as less physical activity, more obesity, increased sodium intake, and decreased potassium intake [from fruits and vegetables].”

It’s crucial for everyone to take steps to prevent themselves from developing high blood pressure early in life, Ferdinand says, especially people at higher risk.

“Elevated blood pressure has a linear, consistent, direct observational relationship to an increase in heart attacks, strokes, heart failure, chronic kidney disease, and early death,” he says.

How to Prevent High Blood Pressure

Keeping yourself from developing hypertension in the first place can go a long way toward reducing your risk of more severe cardiovascular disease.

Willie E. Lawrence Jr., M.D., chief of cardiology at Research Medical Center in Kansas City, Mo., and a spokesperson for the American Heart Association, points to a 2006 study published in the journal Circulation. It found that people who made it to age 50 with fewer than two major risk factors for cardiovascular disease—diabetes, hypertension, high cholesterol, and smoking—were at a much lower lifetime risk for heart disease than those who had two or more risk factors.

Some risk factors, such as a family history of high blood pressure, age, sex, and race, can’t be changed. But no matter how your genetic deck may be stacked, there’s a lot you can do to lower your risk. 

For both the black and white participants in the new study, adhering to the DASH diet (see below) and maintaining a healthy body mass index were linked with a lower risk of developing hypertension. Here’s what to do:

Adopt the DASH diet. The Dietary Approaches to Stop Hypertension (DASH) diet emphasizes eating fruits and vegetables, whole grains, low-fat dairy, nuts, legumes, poultry and fish, and healthy oils. Limit saturated and trans fats, sodium, red meat, sweets and sugar-sweetened beverages. (Read more about following the DASH diet.)

Maintain an appropriate body weight. Following a healthy eating plan, such as the DASH diet, can help keep your weight in check. Eating fewer calories, if you’re taking in too many, and upping your physical activity can also help. Even small reductions in body weight can significantly improve heart health. (See our report for more on weight loss.)

Exercise. According to the American Heart Association and others, getting regular exercise can help lower your risk of hypertension. The new JAMA study didn’t take exercise habits into account, study author Thomas says, but staying physically active “is going to help with body mass index, which does significantly predict hypertension." 

Start early. Among the black male participants in the new study, 30 percent already had high blood pressure by age 35. That means it’s important to develop healthy habits early.

“For all Americans, and especially for those with a positive family history, and for black Americans, it is not necessary to wait until the diagnosis of hypertension becomes manifest before embracing a DASH-type diet” and getting more physical activity, Ferdinand says.

Keep an eye on it. Check your blood pressure regularly, so that you know whether you need to talk to your doctor about lowering it. At a minimum, get it checked every two years if you’re younger than 50, and more often if you’re older than that or have other risk factors for hypertension. It’s easy to get your numbers checked whenever you visit a healthcare provider, or try a home blood pressure monitor.