Brain changes in obesity - and after surgery for obesity

Obesity is a widespread health challenge. It is less commonly known that obesity also affects the brain, leading to reduced cognitive function and executive abilities.

The interplay between obesity and brain health stems from various factors. Neuroinflammation, vascular abnormalities, and increased metabolic stress on the brain cells are just some of the mechanisms that may worsen cognitive issues in obese individuals.

While weight loss through bariatric surgery offers substantial benefits to generel health, the impact of surgery and anesthesia on the brain can be double-edged. Chronic inflammation associated with obesity can amplify after surgery, causing cognitive decline, a condition known as perioperative neurocognitive disorder (PND)

This raises essential questions about how such procedures influence brain health and recovery, particularly in those already vulnerable due to obesity. At the same time, bariatric surgery provides a unique opportunity to study these changes, as it tackles the underlying causes of brain vulnerability.

The study
To explore these dynamics, researchers combined cognitive assessments with magnetic resonance imaging (MRI) of the brain. This approach allowed for a detailed examination of brain changes before bariatric surgery, shortly afterward, and six months later.

Initial findings showed that obese patients had lower cognitive scores and more brain abnormalities compared to healthy individuals before surgery.

After surgery, there was an immediate further decline in cognitive performance in obese people, along with changes in brain tissue structure, such as shifts in gray matter (areas with many brain cells) volume and structure. Possibly due to inflammation or/and cellular changes.

And then it got better ..
Interestingly, by six months, many of these changes showed signs of recovery, with improvements in both brain tissue on MRI scan and the cognitive abilities.

The study also highlighted how different brain regions respond to surgery. MRI scans revealed that the surgery influenced specific regions linked to memory, learning, and executive function, such as the prefrontal cortex and caudate nucleus.

This research provides crucial insights into how bariatric surgery affects the brain.

It suggests that while the surgery itself presents risks, the longer-term benefits of weight loss and improved metabolic health may outweigh the initial challenges.

About the scientific paper:

First author: Bhaswati Roy, USA
Published: Frontiers in Neuroscience, November 2024.
Link to paper: https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2024.1454284/full