Individuals who are Black were found to have accelerated brain aging in midlife whereas individuals who are White and Hispanic exhibited brain aging later in life. These were the findings of a study published in JAMA Neurology.
According to the weathering hypothesis, repeated exposure to social disadvantage, poor environment, and stress can contribute to accelerated wear and tear on the body. Previous studies have evaluated weathering among older populations, but to date it remains unclear whether brain-related signs of weathering can be observed in midlife.
To evaluate ethnic disparities in brain aging during midlife, researchers from Columbia University in the United States sourced data from the Washington Heights-Inwood Columbia Aging Project (WHICAP) and the Offspring Study of Racial and Ethnic Disparities in Alzheimer Disease (Offspring) community-based studies. Trends in magnetic resonance imaging (MRI) data collected between 2011 and 2021 (WHICAP; n=970) and 2017 and 2021 (Offspring; n=497) were evaluated on the basis of ethnicity.
The WHICAP and Offspring cohorts comprised individuals with a mean age, 75 (standard deviation [SD], 6.5) and 55 (SD, 10.7) years, and 65.2% and 65.2% were women, 34.8% and 23.5% were Black, 40.1% and 70% were Hispanic, and 25.1% and 6.4% were White, respectively.
Stratified by ethnicity, significant differences in cortical thickness were observed between individuals in the Black and Hispanic (β, -0.04; P <.001), Black and White (β, 0.06; P <.001), and Hispanic and White (β,-0.03; P =.004) cohorts of the WHICAP dataset. Significant differences in white matter hyperintensities were observed between individuals in the Black and White cohorts of the Offspring dataset (β, -0.36; P =.046) and between Black and Hispanic (β, 0.15; P <.001) and Black and White (β, -0.17; P <.001) cohorts of the WHICAP dataset.
Mean cortical thickness was significantly greater among individuals who are White compared with individuals who are Hispanic and was significantly greater among those who are Hispanic compared with those who are Black.
When age was taken into consideration, cortical thickness was increased in late life compared with midlife among individuals who are White (P =.001) and Hispanic (P <.001) but not those who are Black (P =.64). White matter hyperintensity volume was associated with late life compared with midlife among the individuals in the Hispanic cohort (P =.03).
This analysis may have had limited power as the sample sizes of the ethnic groups differed in the 2 datasets.
The researchers concluded, “Future studies should also include biomarkers reflecting pathology (eg, amyloid and tau) to clarify risk factors and potential pathways that contribute to race and ethnicity disparities in brain aging and AD.”
Additional studies are needed to evaluate brain aging among minority populations.
Disclosure: An author declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Turney IC, Lao PJ, Rentería MA, et al. Brain aging among racially and ethnically diverse middle-aged and older adults. JAMA Neurol. Published online November 14, 2022. doi:10.1001/jamaneurol.2022.3919