The Overlooked Truth: Doctors Once Believed Black People Couldn't Get Diabetes

A hundred years ago, the American medical establishment shared a consensus that seems absurd today: Black people don't get diabetes. This wasn't the speculation of some quack—it was a prejudice shaped jointly by mainstream medical literature and clinical practice at the time. Khalil Green, host of the Vox series "Khalil Explains," traced this history in a video and pointed out that its effects persist to this day.

A "Luxury Disease" Labeled by Class and Race

The story begins in Europe from the late nineteenth to early twentieth century. Doctors at the time noticed a phenomenon: about a quarter of their diabetes patients were Jewish. The observation itself wasn't wrong, but the conclusions drawn from it went astray.

The medical community gradually formed a view: diabetes mainly occurred among wealthy white people and Jews, making it "a great luxury disease." The disease was given a social metaphor—it belonged to the "civilized" and "wealthy."

The implications of this logic were extremely cruel for Black people. Since diabetes was defined as a product of civilization and wealth, doctors tended to believe Black people were "too primitive" to contract the disease at all. In other words, racial prejudice wasn't a misreading of medical data—it was a hierarchy of people imagined first, then diseases assigned to their corresponding positions.

Green adds a key context in the video: these doctors had very little contact with Black patients to begin with. The absence of samples made the prejudice impossible to falsify, and it instead reinforced itself within the medical community.

When Evidence Appeared, It Was Questioned

The most stubborn aspect of prejudice is that it actively rejects counterexamples. Green recounts a case from New Orleans in 1921: a doctor submitted a paper at an academic conference reporting that he had observed diabetes in Black patients.

Another doctor at the conference immediately questioned the finding, on the grounds that the reporter "didn't understand the disease." He even asked: were these patients mixed-race with substantial white ancestry?

This question exposed the internal logic of the entire belief system—the very fact that Black people could get sick was unacceptable, so it had to be explained by "white blood." As long as exceptions were attributed to "not being Black enough," the original racial classification could continue to hold. This was a textbook circular argument, yet it carried considerable legitimacy in academic settings of the time.

Decades of Treatment Gap

The cost of prejudice was concrete and heavy. Green points out that while most diabetes patients began receiving insulin therapy or more reasonable dietary management, many Black Americans with diabetes went untreated for decades.

This wasn't because the drugs didn't exist or the technology was unavailable—it was because diagnosis itself was blocked by prejudice. If doctors don't believe you can get the disease, they won't test for it; if test results are questioned by peers, treatment naturally can't follow. The fruits of medical progress were filtered through racial ideology when distributed.

Insulin was first successfully extracted in 1921 by Canadian scientists Banting and Best, first used in human patients in 1922, and commercially produced by 1923. This breakthrough transformed diabetes from a near-certain death sentence into a long-term manageable chronic disease, and is regarded as one of the greatest achievements of twentieth-century medicine. However, the adoption of new treatments was never uniform. In the United States, insulin initially flowed mainly to urban hospitals and white patients who could afford it, while Black patients in the rural South and poor communities often lacked both specialists and the means to afford long-term medication. The treatment gap was therefore not just the result of diagnostic prejudice—it overlapped with the geographic distribution of medical resources, economic barriers, and racial segregation, together creating a treatment void that lasted for decades.

The Treatment Gap Persists Today

Green emphasizes that this history is not a closed chapter. Even today, Black diabetes patients still face significant disparities in treatment.

One cited statistic: Black diabetes patients are about 20% less likely than white patients to receive GLP-1 drugs. GLP-1 drugs are an important current treatment for diabetes, and Black Americans are precisely one of the groups with the highest diabetes prevalence. Higher prevalence but lower access to key medications—this contrast lies at the heart of contemporary healthcare equity issues.

Green poses his question at the end of the video: why do Black Americans have a far higher rate of diabetes than white Americans, yet have more difficulty accessing treatment? He invites viewers to share in the comments whether anyone in their family has diabetes and whether they knew this history.

GLP-1 drugs (glucagon-like peptide-1 receptor agonists) are a class of medications that regulate blood sugar by mimicking the body's own GLP-1 hormone. GLP-1 is secreted by L cells in the intestine and can promote insulin secretion, inhibit glucagon release, slow gastric emptying, and increase satiety—so it often comes with weight loss alongside blood sugar control. Since the first GLP-1 receptor agonist was approved in 2005, this class of drugs has developed into a major pillar of diabetes treatment, with some varieties proven to have cardiovascular and kidney protective effects. In recent years, GLP-1 drugs such as semaglutide have attracted widespread attention for their significant weight-loss effects, and supply shortages and high prices have further exacerbated inequities in access. For this reason, the lower rate at which Black patients receive these drugs is not just a matter of prescribing habits—it is intertwined with structural factors such as insurance coverage, drug accessibility, and doctor-patient trust.

Why This History Deserves to Be Retold

Telling this history clearly is valuable not just for exposing the absurdities of the past. It serves as a sample showing how medical judgment can be permeated by social prejudice—from disease definition and sample selection to the handling of counterexamples, every step can bear the imprint of its era.

Green's program places historical threads and current data on the same narrative line, and this is precisely the intent: today's treatment gap didn't appear out of nowhere—it has a traceable ideological origin. Understanding this is the starting point for discussing healthcare equity.

The full video can be viewed on Vox's YouTube channel.

In medical sociology, this phenomenon is often called the "racism, not race" explanatory framework: health disparities between groups often stem not from biological race itself, but from how society treats these groups. The U.S. National Institutes of Health has promoted minority health research since the 1990s precisely because growing evidence shows that the roots of health disparities lie in structural factors—residential segregation, environmental exposure, healthcare accessibility, and implicit bias in the medical system. This diabetes history provides a complete case study: from missing samples at the disease-definition stage, to suspicion at the diagnostic stage, to resource allocation at the treatment stage, prejudice appeared at every step in the guise of "scientific judgment," making correction extraordinarily difficult.

One-line Summary

Diabetes was once defined as a "luxury disease," and racial prejudice led to Black patients being neglected for decades—effects that persist today.

Paragraph Summary

The article traces a forgotten chapter of medical history: from the late nineteenth to early twentieth century, European and American doctors viewed diabetes as a "luxury disease" of wealthy white people and Jews, concluding that "primitive" Black people wouldn't contract it. In 1921, a New Orleans doctor reported diabetes cases in Black patients but was questioned by peers who demanded a "white ancestry" explanation—exposing circular reasoning. Prejudice meant many Black patients went undiagnosed and untreated for decades while insulin became widespread. Green notes this history isn't over—Black diabetes patients are still about 20% less likely to receive GLP-1 drugs than white patients, even though Black communities have among the highest diabetes rates. The article shows how medical judgment can be permeated by social prejudice and calls for understanding healthcare equity by connecting historical threads with current data.