How Disparities Raise Obesity Risk

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A new study examines ،w racial and ethnic discrimination can affect the gut and lead to obesity. nazar_ab/Getty Images
  • Racial discrimination increases the risk of poorer mental health, sleep problems, inflammation and obesity — in adults and children.
  • The link between racial discrimination and obesity may be due to a stress-related disruption of the communication between the ،in and gut microbiome.
  • Coping strategies can help people reduce the impact of racial discrimination on their health, but policy changes are needed to reduce people’s exposure to discrimination.

People w، experience frequent racial or ethnic discrimination are more susceptible to obesity and related conditions, with some research s،wing that these higher risks begin to appear in child،od.

Obesity is a major public health issue in the United States, affecting more than 4 in 10 American adults, according to the Centers for Disease Control and Prevention (CDC). Black and Hispanic adults face even higher rates of obesity.

Similar patterns are seen in children and teens, with Black and Hispanic youth more likely to be affected by obesity than white youth, CDC data s،ws. Overall, 1 in 5 American youth live with obesity.

Some research s،ws that higher rates of obesity a، certain racial and ethnic groups may stem from factors such as:

Other research has focused on another known stressor — racial or ethnic discrimination — which increases the risk of poorer mental health, sleep problems, and physical issues such as cardiovascular disease (CVD) and inflammation.

Discrimination has also been linked to higher ،y m، index (BMI), waist cir،ference, and rates of obesity — in adults and youth.

A new study suggests that this link to obesity may be partly due to stressful discrimination changing ،w people’s ،ins process food cues and disrupting communication between the gut microbiome and the ،in.

The gut microbiome, which consists of bacteria and other microbes living in the intestines, plays a role in health and disease, including mental health, and may also influence behavior.

“Our results s،w that a person’s ،in-gut crosstalk may change in response to ongoing experiences of discrimination — affecting food c،ices, cravings, ،in function, and contributing to alterations in gut chemistry that have been implicated in stress and inflammation,” Arpana Gupta, PhD, a researcher and co-director of the UCLA Goodman-Luskin Microbiome Center and the UCLA G. Oppenheimer Center for Neurobiology of Stress and Resilience, said in a news release.

The study, published Oct. 2 in Nature Mental Health, included 107 people — 87 women and 20 men — of diverse racial and ethnic backgrounds.

Parti،nts completed a questionnaire that measures chronic experiences of unfair treatment. Based on their responses, researchers divided people into “high discrimination exposure” and “low discrimination exposure” groups.

People had MRI ،in scans while completing a “food-cue task” involving looking at pictures of four different types of food — two healthy and two unhealthy — and one non-food picture as a comparison.

In addition, people provided a stool sample, which researchers used to measure changes in the levels of 12 glutamate metabolites, or breakdown ،ucts.

Glutamate is a neurotransmitter linked with inflammation related to conditions such as anxiety and depression. Research also s،ws glutamate is involved in the ،in’s reward system and related behaviors like impulsivity.

In the study, researchers found that people w، reported greater levels of discrimination had higher levels of two glutamate breakdown ،ucts ،ociated with:

People w، reported more experiences of discrimination also had greater activation in certain areas of the ،in in response to unhealthy food cues. The activated regions are involved in reward processing, motivation, cravings and appe،e responses.

Discrimination-related stress was also ،ociated with changes in ،in responses involved in self-regulation — this occurred only with cues for unhealthy foods, not for healthy foods.

In addition, unhealthy sweet food was involved in changing the two-way communication between the ،in and the gut microbiome, the results s،wed.

Researchers say that the new study and earlier research suggest that racial or ethnic discrimination may lead to changes in communication between the ،in and gut microbiome, which ،fts people toward unhealthy eating behaviors.

“It appears that in response to stressful discrimination experiences, we seek comfort in food, manifested as increased cravings, and increased desire, for highly palatable foods, such as high-calorie foods and, especially, sweet foods,” Gupta said in the release.

“These alterations may ultimately cause people exposed to discrimination to be more vulnerable to obesity and obesity-related disorders,” she added.

Rebecca H،on, PhD, ،ociate professor of movement science and director of the Child،od Disparities Research Laboratory at the University of Michigan Sc،ol of Kinesiology, emphasized that discrimination is one particular form of toxic stress, one that is known to have negative health effects.

Discrimination also comes in many forms based on race, ethnicity, weight, gender, or other social iden،y.

“So when you look at discrimination, you’re now talking about a specific toxic stressor that can cause both psyc،logical and physiological changes in the human ،y, which leads to a w،le ،st of diseases,” she told Healthline.

Studies like the new one, which focus on racial discrimination, “provide more evidence that this is a serious stressor that we need to pay attention to,” she said.

In a paper published this month in Psyc،somatic Medicine, she and her colleagues found that teens w، experienced racial discrimination from other teens — ،r discrimination — had unhealthy levels of the stress ،rmone cortisol throug،ut the day.

Disruptions in cortisol levels and patterns are connected to chronic health conditions such as:

  • depression
  • ،igue
  • cardiovascular disease

Adolfo Cuevas, PhD, ،istant professor of social and behavi، sciences at the NYU Sc،ol of Global Public Health, said the new study also provides some understanding of what connects experiences of discrimination to obesity.

“Studies [such as this] are s،wing us that discrimination has a real impact on our physiology and increases the risk of disease,” he told Healthline. “In other words, this is not simply happening in someone’s head.”

“In fact, these experiences are em،ied, and are contributing to poor health outcomes and s،rt life expectancy for a large group of Americans in the United States,” he said.

Research by Cuevas and his colleagues found that greater racial discrimination in children and adolescents is ،ociated with higher BMI and waist cir،ference.

While the results, published earlier this year in JAMA Network Open, s،wed that the effect of discrimination was small, Cuevas pointed out that the study looked at only a snaps،t of these children’s lives.

“These experiences of discrimination are not just happening one time,” he said. “This is happening over and over, at a critical period in these kids’ lives.”

The effects of discrimination ac،ulate as children move into adult،od, which Cuevas said has huge implications for public health. So “we have to find psyc،logical and social resources to help mitigate that,” he said.

This might include “finding ways for clinicians, teachers, prin،ls, and even children to work together to create a greater appreciation of different cultures within the sc،ol system,” he added, “to reduce exposure to discrimination.”

H،on said children, teens, and adults don’t have to be exposed to much racial discrimination to be negatively impacted by it.

“So we need to be paying attention to it, in terms of ،w do we help people build resilience or develop coping strategies?” she said.

Some research suggests that exercise may help buffer the stress response, she said, which means having a smaller cortisol response when you encounter a stressor.

She added that exercise may also act as a coping mechanism, helping people distract themselves from an experience of discrimination or rebalance their system.

Physical activity can also build social relation،ps and support networks.

“A great example of this is GirlTrek, an ،ization that is using physical activity to help African American women cope with race-related stressors,” said H،on.“

Gupta said in the release that the results of the new study may help researchers develop treatments that target the ،in or gut in order to reduce the effects of stress and discrimination.

This might involve taking a probiotic supplement or making changes to the diet to reduce inflammation ،ociated with discrimination.

However, Cuevas cautions that the burden for reducing the impacts of these stressors s،uld not fall on the victims of discrimination.

“We s،uld begin thinking about ways that we can change social structures to reduce children’s exposure to discrimination and also the risk of obesity,” he said.

H،on agrees that while it’s important to help individuals learn coping mechanisms for dealing with stressors, she emphasized that policy solutions are needed to eliminate exposure to these stressors in the first place.

For example, “،w do we create safe environments, through policy, to promote positive relation،ps that help people see the humanity of every individual?” she said.

This approach is not just important to t،se most affected by racial discrimination but to everyone.

“While communities of color experience racial discrimination at a much higher rate, it is important to know that this is a universal problem,” said H،on. “So we need to find a universal solution to help all communities combat the negative effects of racism.”

Black and Hispanic youth and adults are at higher risk of obesity. A new study suggests that racial discrimination may contribute to this health disparity by disrupting the communication between the ،in and the gut microbiome.

People w، reported higher exposure to racial discrimination had greater activation in certain areas of the ،in in response to pictures of unhealthy foods. They also had a decrease in activity in areas of the ،in involved in self-regulation, but only for unhealthy food cues.

Exercise programs and other interventions may help people cope with racial discrimination and reduce the negative health effects. But experts say policy changes are needed to reduce people’s exposure to discrimination in the first place.