Chronic experiences of discrimination may have a measurable impact on immune function, potentially leading to a weakened ability to fight off illness, according to new research published in . The study, appearing in Brain, Behavior, & Immunity – Health, suggests that the persistent stress associated with everyday discrimination can lead to an accumulation of “exhausted” white blood cells.
Researchers at NYU School of Global Public Health examined data from over 6,300 adults aged 50 and older, combining survey responses about experiences with discrimination with analysis of blood samples. The findings indicate a significant association between higher levels of reported discrimination and elevated counts of specific types of T and B cells – crucial components of the adaptive immune system – that have entered a state of exhaustion.
How Discrimination Impacts the Immune System
The study builds on existing knowledge linking stress to immune suppression. However, it delves deeper into the specific cellular mechanisms by which discriminatory experiences might alter immune function. “Our findings suggest that everyday experiences of social disadvantage leave physiological traces that accumulate over time,” explains Emiko Kranz, a PhD student at NYU School of Global Public Health and the study’s first author.
The research focused on “everyday discrimination” – instances of unfair treatment based on factors like race, gender, or economic status. Participants were asked about experiences such as being treated with less respect, being perceived as unintelligent, or receiving poorer service in public settings. These subtle, yet frequent, slights can contribute to chronic stress, which is known to disrupt immune system regulation.
While the link between stress and a compromised immune system is well-established, this study highlights a potential pathway through which discrimination exerts its effects. Scientists hypothesize that repeated activation of the body’s stress response due to discriminatory experiences leads to a process known as “weathering,” resulting in the gradual deterioration of health. Previous research has largely focused on the connection between discrimination and inflammation, but this study expands the understanding to include the adaptive immune system.
Examining Immune Cell Function
The researchers analyzed blood samples for biomarkers of immune system activity, specifically focusing on T cells and B cells. They discovered that individuals reporting higher levels of everyday discrimination had elevated counts of certain terminally differentiated T cells (CD4+ TEMRA and CD8+ TEMRA) and B cells (IgD− memory). These cells, unlike their “naïve” counterparts, have undergone repeated activation and are transitioning into an exhausted state.
“We weren’t only looking at whether there were more or less of the B cells and T cells; we were also able to see what period of their life cycle and level of functionality they had based on whether they were naïve or terminally differentiated cells, which gave us additional insight,” Kranz noted. Terminally differentiated cells have diminished functionality and a reduced capacity to mount robust immune responses, potentially hindering the body’s ability to effectively fight off infections and other threats.
Implications for Health Disparities
The findings have important implications for understanding and addressing health disparities. Discrimination is a pervasive social issue that disproportionately affects marginalized communities, and this research suggests that its effects extend beyond psychological stress to impact physical health at a cellular level. The accumulation of exhausted immune cells could contribute to increased susceptibility to illness and potentially accelerate the aging process.
“This study builds upon well-established research linking experiences of discrimination to systemic inflammation, revealing yet another way that psychosocial stressors become embodied and may contribute to age-related disease processes,” says Adolfo Cuevas, associate professor of social and behavioral sciences at NYU School of Global Public Health and the study’s senior author.
Looking Ahead
The authors emphasize that this study is a starting point for further investigation. More research is needed to fully elucidate the complex relationship between discrimination and immune system function. Understanding these mechanisms is crucial for developing interventions aimed at mitigating the health consequences of discrimination and promoting equitable healthcare. The study also highlights the importance of addressing social determinants of health and creating environments that foster inclusivity and respect.
The research team acknowledges the limitations of observational studies, noting that correlation does not equal causation. However, the findings add to a growing body of evidence demonstrating the detrimental effects of discrimination on well-being and underscore the need for continued research in this critical area. As noted in a related report from , discrimination is linked to diminished immune system function, and further study is needed to understand the connection.
Support for the research came from the National Institute of Diabetes and Digestive and Kidney Diseases.
