Examining Cerebral Blood Flow as a Mechanism for the Effects of African Dance on Executive Function

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Abstract African Americans are almost two times more likely than whites (i.e., Caucasians) to experience Alzheimer’s disease or other dementias. For those over the age of 65, the prevalence of cognitive impairment is 8.8% in whites and 23.9% in African Americans. Even in the age range of 55-64, African Americans are 4 times more likely to experience cognitive impairment than their age-matched white counterparts. One process that is believed to contribute to this disparity is age-related decreases in cerebral blood flow, which is particularly harmful for executive function performance. A critical public health question emerges from these statistics that we intend to address in this proposal: Is there an effective method for reducing or eliminating the race disparities in cognitive and brain health, and does this method work by augmenting cerebral blood flow? Fortunately, physical activity (PA) interventions may be effective at improving neurocognitive function and reducing risk for dementia. Despite these promising results, the mechanism by which PA may improve neurocognitive function remain unknown. Additionally, prior PA interventions have had few African Americans making it difficult to stratify results by race to determine whether African Americans respond to PA in a similar manner and magnitude as whites. The terms ‘physical activity’ and ‘exercise’ are often considered unpleasant, painful, and fatiguing, which can negatively influence interest, enrollment, and long- term adherence. Methods that increase PA without using the term PA (e.g., dancing) could be effective at improving health outcomes while simultaneously having a wider impact on translation and long- term adherence. Here we propose an innovative and culturally sensitive method of increasing PA in older (60- 80 yrs) African Americans. We propose a randomized intervention where 180 older African Americans are assigned to either a moderate intensity African Dance group 3 days per week (N=90) or to an African Education group 3 days per week (N=90) for 6-months. Both before and at the completion of the intervention, we will collect a comprehensive neuropsychological battery and MRI metrics of brain health and function to elucidate cerebrovascular pathways by which PA influences neurocognitive health in an African American population. This proposal has the potential to utilize community-based activities to improve health of older African Americans. In addition, it could establish a platform (i.e., dance) to implement future interventions targeting minority populations to reduce health disparities. We have three primary aims: Aim 1. Examine whether a 6- month African Dance intervention improves executive function compared to an educational control group. Aim 2. Examine whether African Dance increases cerebral blood flow in the prefrontal cortex. Aim 3. Examine whether changes in prefrontal cortex cerebral blood flow mediates the relationship between African Dance and improvements in executive function.