Obesity and brain inflammation linked

Research from Radboud University in the Netherlands suggests that chronic inflammation related to obesity may affect a part of the brain responsible for decision-making. This could reduce motivation to choose healthy meals, potentially creating a cycle where obesity leads to a preference for processed foods.

Study design and participant details

The study included 131 women with a body mass index above 27. They underwent functional MRI scans while performing a decision-making test that involved squeezing a grip with different levels of force to get food. Researchers used blood tests to calculate an inflammation score based on four biomarkers, including C-reactive protein and white blood cell counts.

Inflammation and decision-making

Participants with higher inflammation scores were more likely to avoid tasks that required more effort, with the odds of rejection dropping by 73%. The brain region involved in evaluating effort, the dorsomedial prefrontal cortex, showed increased activity as inflammation levels rose.

Anti-inflammatory drug trial results

A clinical trial with 49 women who had a high body mass index and elevated C-reactive protein levels found that those taking colchicine, an anti-inflammatory drug, were 32% more likely to choose effortful options. Brain activity in the prefrontal cortex also showed a trend toward decreasing, though the results were not statistically significant.

Biological mechanisms and gender bias

Excess body fat can attract immune cells called macrophages, which release proteins that interfere with dopamine production. This affects motivation and leads to a preference for high-fat and high-sugar foods. While similar drugs have reduced food intake in rodents, this study only included women, which may limit the findings. Researchers suggest including men in future studies to better understand these effects and develop new treatments.