Obesity, Inflammation, and Working Memory: Evidence of a Vicious Cycle

https://doi.org/10.1016/j.bbih.2021.100202

Commentary

Overweight and obesity are the fifth leading cause of death worldwide, although they are preventable.

One pathway through which overweight contributes to poor health can be described as inflammatory activity and altered cognitive processes.

Previous theories proposed a vicious cycle in which obesity increases inflammatory activity, which in turn alters cognitive processes such as working memory, and then leads to a decreased ability to self-regulate and manage weight.

However, there are no longitudinal studies that have investigated this potential dynamic.

This study addressed this gap by assessing the relationship between fat mass, C-reactive protein (CRP), and working memory over time in a large sample of 8536 adolescents in the Avon Longitudinal Study of Parents and Children.

Adiposity was quantified by dual emission x-ray absorptiometry (DEXA) at ages 9 and 15.5 years, and inflammatory activity was indexed by circulating serum C-reactive protein (CRP) levels assessed by a highly sensitive assay at the same ages.

Working memory was assessed between these two time points, at age 10 years, allowing the investigation of temporal relationships between working memory, obesity, and inflammatory activity.

Results showed that fat mass predicted later working memory deficits and that this association was statistically mediated by CRP.

Furthermore, we found that deficits in working memory predicted subsequent increases in fat mass and CRP, and that the link between working memory and subsequent CRP was partially mediated by fat mass.