During the study, the team examined the impact of obesity caused by dietary changes and subsequent weight loss in young and middle-aged mice. Both groups demonstrated successful restoration of normal blood glucose levels after weight loss, indicating that metabolic improvements occur regardless of age.
However, middle-aged mice exhibited increased inflammatory processes in the hypothalamus—a region of the brain responsible for regulating appetite and energy consumption, as well as other critically important functions. This inflammation was recorded both at the molecular level and through detailed microscopic visualization of microglia, the brain's immune system cells. The inflammatory response persisted for several weeks before beginning to wane.
Although the long-term consequences of this inflammation remain unclear, the study's findings raise serious concerns. Chronic or uncontrolled inflammation in the brain is associated with memory problems and an increased risk of developing neurodegenerative diseases such as Alzheimer's disease.
“Our data suggest that the process of weight loss in adulthood is not simply a repetition of successful methods used in youth. Weight loss is important for restoring metabolic health in obesity, but it is essential to study how it affects brain health in adulthood to avoid deterioration,” noted Alon Zemer, the lead author of the study.
The researchers emphasize the need for further studies to better understand the mechanisms leading to temporary inflammation in the brain during weight loss in middle age. Future research may help develop strategies that allow for the preservation of the metabolic benefits of weight loss while simultaneously protecting brain health.
