A new study suggests that Black women with heart health issues may experience earlier cognitive decline compared to white women. The research, conducted over a 20-year period, found that processing speed declined in Black women during midlife, but working memory did not decline in either group. The study, published in the Journal of the American Heart Association, involved 765 women in the Chicago site of the Study of Women’s Health Across the Nation (SWAN). Participants included 363 Black and 402 white women between the ages of 42 and 52 who did not have cardiovascular disease. Cognitive and working memory assessments were completed annually or biennially over a maximum of 20 years, with an average follow-up of nearly 10 years.
The researchers measured cardiovascular health using the American Heart Association’s Life’s Essential 8 checklist, which includes blood pressure, body mass index, glucose, cholesterol, smoking, physical activity, diet, and sleep. Dr. José Morales, a vascular neurologist and neurointerventional surgeon, emphasized the importance of addressing cardiovascular risk factors early to prevent cognitive decline. While the study aimed to control for baseline demographic differences, Morales cautioned against drawing conclusions based solely on racial differences, as there are numerous factors at play. The researchers sought to determine whether better cardiovascular health was associated with less cognitive decline in Black and white women during midlife.
Findings from the study revealed that processing speed declined in Black women with lower heart health, but not in white women, while working memory did not decline in either group. Working memory, defined as the short-term storage of information used in cognitive tasks, was not affected by cardiovascular health in either Black or white women. Imke Janssen, a professor at Rush University Medical Center and study author, explained that within the Black subgroup, those with lower cardiovascular health experienced faster declines in processing speed. Factors such as blood pressure and smoking were identified as key contributors to these differences, with Black women having higher rates of hypertension compared to white women.
The research highlighted the biological plausibility of these findings, pointing to factors such as nicotine exposure and smoking habits in contributing to cognitive decline among Black women with poor cardiovascular health. For Black individuals, serum cotinine levels, a marker of nicotine exposure, were higher than in white individuals, potentially due to lower cessation rates. Janssen emphasized the importance of optimizing cardiovascular health in midlife Black women to slow cognitive aging, increase independence, and reduce the risk of dementia. She suggested that a clinical study would be necessary to assess the impact of improving cardiovascular health on cognitive outcomes.
Morales stressed the need for additional studies to further explore differences in working memory between Black and white women. He noted potential confounders in working memory assessments, such as practice effects, which may have influenced the study’s results. Future research should focus on more robust measures of working memory without the practice effect confounder to determine the reproducibility of the findings. Understanding the relationship between cardiovascular health, cognitive decline, and racial disparities in dementia risk is crucial for developing interventions to improve cognitive outcomes for all populations.