A new study published in the Journal of Alzheimer’s Disease suggests that the brains of older adults with obesity show patterns of gray matter loss similar to those seen in people with early Alzheimer’s disease. The spatial distribution of the tissue loss may help explain why obesity is a major risk factor for Alzheimer’s, however, the study cannot reveal the exact cause of the tissue loss nor predict which of the cognitively healthy, obese participants might develop dementia.
The study used brain scans from over 1,300 individuals and found that the regions thinned out in people with obesity and Alzheimer’s include the right temporo-parietal cortex and left prefrontal cortex, which are involved in high-level cognitive functions such as long-term memory, language, attention, and executive functioning. Conditions like systemic inflammation, high blood pressure, and type 2 diabetes which often occur in obesity can potentially harm brain cells and have been linked to Alzheimer’s-related brain changes. However, there may be brain-thinning mechanisms in obesity that are independent of those seen in Alzheimer’s. The researchers aim to conduct a large clinical trial in the future to see if weight loss treatments can prevent cortical thinning and cognitive decline. However, it is unclear when such interventions should start, as once a neuron dies, it will not be replaced.