Grant: Project Grant

The size of Canadian population aged 65 and older is growing, so will the number of individuals with dementia. Exercise is a viable dementia prevention strategy. To maximize the utility of exercise (e.g., by providing personalized exercise recommendations), it is vital to determine factors that influence its effectiveness. Exercise type and a person's genotype are factors that require further investigation. There are 2 main types of exercise, aerobic training (AT) and strength training (ST). Both have benefits for brain health, but do so using different biological pathways. Specifically, AT appears to largely rely on the release of a particular protein called brain derived neurotrophic factor (BDNF). In contrast, ST is not BDNF-dependent, but relies on another protein. Understanding how both AT and ST benefit the brain is important because in ~35% of the population, there is an alteration within the BDNF gene that results in less secretion of BDNF. Thus, we believe this BDNF gene variant may determine the degree of benefit an individual will receive from AT. Specifically, we speculate that persons with this BDNF gene variant will not experience the same degree of brain health gains from AT as those without this gene variant. Thus, for individuals with this BDNF gene variant, ST may be the more appropriate form of exercise training to promote brain health. For our research, we will examine how this BDNF gene variant may modify the degree of brain health benefits from 6 months of 3 times per week AT or ST, in older adults at risk for dementia. Our study is critical to understanding how genes may influence the cognitive response to different types of exercise training. Given the immense health and financial burden imposed by dementia, our proposed study could have major impact in Canada and internationally as the results will contribute to evidence-based, personalized exercise recommendations for dementia prevention.