Perceived racism linked to weight gain, Boston researchers say
Perceptions of racism -- from being treated with suspicion in a store to unfairness in employment or housing -- can heighten stress levels and affect health, research has shown. A new study from Boston University links these smoldering signs of racism to weight gain in black women, suggesting a possible explanation for the their higher obesity rates compared to white women.
Yvette Cozier, an epidemiologist at the Slone Epidemiology Center at BU, led a survey of more than 43,000 women enrolled in the long-running Black Women's Health Study. Writing in the June issue of Annals of Epidemiology, she and her co-authors describe participants' reports on their weight, body mass index, and perceptions of racism.
At the beginning of the eight-year study, the women were asked if they sometimes felt they were treated poorly in a restaurant or store, whether they thought people considered them dishonest or less intelligent, and if they had felt unfairness on the job, in housing, or from police. The women, 21 to 69 years old at the study's outset, were placed in four groups based on how frequently they said they experienced these signs of racism. Their weight was recorded every two years from 1997 through 2005. Their waist circumference was measured at the beginning and end.
At the end of the trial, all the women had gained weight. But the women who said they felt higher levels of racism gained more weight and had bigger waist-size increases compared to the women who felt the least racism. That held true after accounting for factors such as education, geographic region, and beginning body mass index.
"Racism is real and it has real effects," Cozier said in an interview. "It can result in real changes in the body."
Higher stress changes hormone levels that influence food choices and where in the body fat is stored, the authors write. That makes an association between the stress of racism and weight gain, particularly around the waist, fit with other research in humans and animals, they say.
Cozier said she was interested in learning whether there was another reason beyond diet and exercise that could explain why black women tend to be heavier than white women. Her study did not include white women, so a direct comparison is not possible, she said, but the unique experience of racism appears to be a potential contributor to the difference.
Her findings are in line with other research on the impact of discrimination, particularly as it relates to premature aging and high blood pressure, Dr. Joseph Betancourt, director of the Disparities Solutions Center at Massachusetts General Hospital, said in an interview. He was not involved in the BU study.
"We are learning more and more about the mind-body connection and the impact of perceptions of discrimination, whether they be large episodes or these micro-insults on a day-to-day basis, including walking down the street and having somebody cross over the street" to avoid you, he said. "Discrimination turns into stress and it can have an incredible impact on the body."
Clinicians should understand that racism may affect their patients in ways they might not expect, Cozier said.
"It is useful for us in America to just understand that racism hasn't gone away," she said. "It's gotten better, but it's still here."