Obesity as a risk factor for dementia and cognitive impairment - a systematic review

Abstract

Obesity, affecting One in eight people, poses significant health risks, including an increased risk of cognitive impairment and dementia. This article is exploring the complex and multifaceted relationship between obesity and cognitive function, highlighting several mechanisms that may contribute to cognitive decline in obese individuals. Research reveals that obesity in middle age is associated with a higher risk of cognitive decline, while in older adults, it might provide some protection against rapid cognitive deterioration. In adolescents, obesity is linked to lower scores on cognitive tests, indicating damaging effects on cognitive abilities from an early age. Key mechanisms discussed include neuroinflammation, mitochondrial dysfunction, and insulin resistance. Neuroinflammation involves elevated levels of pro-inflammatory cytokines leading to increased blood-brain barrier permeability and potential neuronal damage. Mitochondrial dysfunction in obesity results in impaired neuronal function due to disrupted mitochondrial processes. Insulin resistance, a common feature of obesity, affects brain regions critical for memory and executive functions. Additionally, the impact of weight loss on cognitive function is examined, with evidence suggesting that weight reduction through bariatric surgery, lifestyle interventions, or pharmacological treatments can improve cognitive abilities. However, further research is needed to establish definitive causal relationships and to understand the underlying biological changes.