In a study that is sure to fan an age-old scientific debate, Johns Hopkins researchers have attributed the high rates of hypertension among blacks to the stresses of living with racism, poverty and low educational levels -- not to genes.
The scientists did not entirely dismiss a genetic link but suggested that stress is the leading reason why blacks suffer disproportionately from high blood pressure -- a disease that is major contributor to heart failure, kidney disease and strokes.
"We live in a race-conscious society, where darker skin color is probably a marker for exposure to psycho-social stress," Dr. Michael A. Klag, the lead investigator, said in an interview yesterday.
The study, described in today's Journal of the American Medical Association, found that hypertension was common among dark-skinned blacks who lacked jobs or a high school education. But the disease was far less common among dark-skinned blacks with higher educational and income levels.
If genes were the predominating factor, Dr. Klag said, the health problem should persist equally among both groups -- regardless of economics or education.
The article won praise yesterday from Dr. Benjamin L. Hooks, executive director of the National Association for the Advancement of Colored People, who said that the study "gives scientific support to something we have known for generations -- it's not easy being black in America."
"If you are born black in this country, the unfortunate fact is that stress is a part of your life," Dr. Hooks said. "Others may find this difficult to believe, but if you look at our cultural heritage -- our poetry, songs, prose and arts -- you will find much of it is concerned with the dichotomy of being black in a race-conscious society."
Some scientists, however, said that the weight of scientific evidence from a variety of studies suggests that genetic factors predispose blacks to high blood pressure.
For many years, scientists have been trying to sort out the reasons why hypertension strikes blacks twice as often and five to seven times as severely as it does people of other races. The International Society on Hypertension in Blacks estimates that two-thirds of blacks over age 50 have high blood pressure.
