‘African Gene Theory’ Is a Myth, and It’s Harming Black Men’s Heart Health

YOU WOULD never think that a 1988 American Heart Association (AHA) conference would set the stage for decades of debate around—of all things—sodium and race. But that’s where Clarence Grim, M.D., seeded a theory about Black health that has been difficult to uproot ever since.

Dr. Grim, then the director of the hypertension research center at the Charles R. Drew University of Medicine and Science in Los Angeles, hypothesized that high rates of hypertension among African Americans were due to the horrors of slavery, including the Middle Passage, the mass transport of slaves from West Africa to North America from roughly 1600 to 1800.

These brutal experiences forced a genetic shift, Dr. Grim argued, that allowed those who were genetically predisposed to retain more sodium in their blood (the definition of hypertension) to survive.

Descendants of the hypertensive slaves, he said, perpetuated the gene. {snip}

Dr. Grim’s theory, critics said, was based not on scientific data and evidence but on historical accounts of slavery.

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And yet despite all this criticism, gene theory as it applies to sodium and the health of Black people settled into and persisted within certain sectors—and still rears its head.

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The websites of the Centers for Disease Control and Prevention and the AHA, not to mention health websites such as WebMD and Medscape, contain references to gene theory and hypertension.

On the “High Blood Pressure and African Americans” page, the AHA states that “researchers have also found that there may be a gene that makes African Americans much more salt sensitive.”

The truth: There’s no gene.

“There is no reason to assume that major genetic discontinuities exist between different continents or ‘races,’ ” a 2004 study published in Genome Research concluded. A 2012 Harvard study found no connection between genetics and hypertension. The salt-sensitivity-gene myth persists largely because there’s a dearth of medical studies involving Black people.

It persists because it’s a systemic problem that goes well beyond sodium, one that arises via generalizations within the medical community, as well as resistance from Black people to signing on as study participants due to past mistreatment.

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Black people do suffer from hypertension disproportionately. In fact, the prevalence of high blood pressure in African Americans in the United States is among the highest in the world. More than 40 percent of non-Hispanic African American men and women have the condition, and roughly 42 percent of Black men age 20 and older have high blood pressure.

The CARDIA study published in the Journal of the American Heart Association also revealed that by age 55, 76 percent of Black people had developed high blood pressure, compared with 55 percent of white men and 40 percent of white women. Sodium intake has, for decades, been a primary target for better heart health, but that doesn’t mean sodium is inherently evil.

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Hypertension can lead to heart disease, heart failure, and stroke, but scientists know now that sodium is one of many factors that may increase your risk. There’s an overemphasis placed on sodium and not as much focus on how it fits into diet, lifestyle, and family history, says Raymond Benza, M.D., the director of cardiovascular medicine at the Ohio State University Wexner Medical Center. This is particularly true as it pertains to challenges in the Black community.

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Yet even Dr. Benza, a funded investigator for the AHA, says that ethnic differences in sodium sensitivity have a lot to do with heredity and natural selection. “In those of African descent, the need to retain salt in the environment they operated or lived in was a necessity, because salt was a rarity in these areas. So the body built adaptations to retain salt in those climates,” he says.

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The Tuskegee Study, in which doctors purposefully neglected to provide appropriate treatment to Black men in order to study the long-term effects of syphilis, lasted from 1932 to 1972 and gave Black Americans ample cause to distrust medical researchers.

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In addition to an inability to access care and the possibility that Black people may not be asked to participate in studies as often as others, this distrust remains.

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Black participation in clinical trials for 24 of the 31 cancer drugs approved by the FDA since 2015 stands at less than 5 percent—despite non-Hispanic Black people constituting 13 percent of the U. S. population.

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Dr. Grim, the cardiologist who presented at the 1988 AHA conference, is still consulting, researching, and writing, and he says he stands by his theory.

“It has nothing to do with race,” he says.

“It has to do with the physiology of the individual that is salt sensitive.” {snip}

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Bridges, the UC Berkeley School of Law professor, says this is still faulty thinking.

“Researchers are not looking for genetic causes that might predispose white folks to death. They are just looking at Black people, which is bad science all around.” She adds that doctors wrongly assume race is a biological factor and look for data that supports that conclusion.

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Gene theory and sodium-reduction prescriptions also overlook one major factor in high blood pressure: stress. “It is stressful to be a person of color and live in a racist society,” Bridges says.

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