Dementia has become a public health concern. Current evidence indicates that reducing exposure to modifiable risk factors reduce the risk of developing dementia by 45%, making prevention the best strategy. However, many of these risk factors are themselves chronic diseases that require challenging behavioral changes and interventions. For example, obesity is a modifiable risk factor, but is linked to other risk factors, such as diabetes, hypertension, and depression. Another comorbidity associated with obesity is iron deficiency (ID). Although studies have shown that ID is more prevalent in populations with obesity, it has received little attention in clinical care for obesity. Given that iron is an essential micronutrient for energy production, ID in obesity should be more carefully investigated. Indeed, our recent studies have shown that women with obesity and concomitant ID have an increased body fat percentage and elevated circulating fatty acids. In experimental animal models, we have demonstrated that ID establish a protein profile indicative of an increased use of fatty acids as fuel in certain brain regions. Our ongoing in vitro study also indicates that ID increases uptake of fatty acids across the blood-brain barrier model, suggesting that elevated circulating fatty acids may be transported into the brain and impact its energy homeostasis. Therefore, the combination of obesity and ID may further impair cognitive performance. To test this hypothesis, we plan to build a cohort comprising four main groups based on obesity and iron status using data from the UK Biobank and examine the relationship between these factors and cognitive function. Data obtained from this analysis can be compared to the data obtained from our Brazilian prospective cohort, which is currently being established. Comparing data from both cohorts will be valuable in investigating ethnic and sociodemographic differences related to the studied topics.
