A joint study by US, Chinese and German scientists has reported GLP-1 drugs – such as Wegovy and Ozempic (semaglutide) and Zepbound (tirzepatide) – may offer neuroprotective benefits by reducing inflammation in the brain and strengthening the blood-brain barrier.
The research, published in the journal Cell Metabolism, examined how GLP-1 drugs can balance the neurovascular unit (part of the brain that regulates blood flow within the brain), thereby creating the possibility of improving cognitive functioning.
Another recent Chinese study at Jilin University had indicated obesity and chronic low-grade inflammation are a ‘pathway’ to developing Alzheimer’s disease; as scientists continue ‘working to find ways to prevent and slow the progression of neurodegenerative diseases, the category of GLP-1 drugs has become a focus of research’, noted medicalnewstoday.com.
Chronic low-grade inflammation can impact the brain by affecting glial cell functioning. Glial cells include astrocytes (which perform neuroprotective tasks and form the blood-brain barrier) and microglia (immune cells that sustain the blood-brain barrier and remove damaged cells in the brain, but changes in which can lead to neurodegeneration).
The blood-brain barrier protects the brain from harmful substances and infection; inflammation in people with obesity may result in reductions in their blood-brain barriers.
The latest review shows cell signalling from GLP-1 drugs may interact with these cells and provide brain health benefits. It found ‘GLP-1 receptor signalling in astrocytes regulates both central and peripheral metabolism, extending from energy balance to neuroplasticity’. This signalling also enhances neuron growth, and an increase in astrocytes also increases neuron survival.
With microglia, the review found some studies believe GLP-1 receptor signalling can reverse inflammation: ‘GLP-1R signalling on microglia attenuates neuroinflammation by suppressing the polarisation of microglia to a proinflammatory state.’
The review authors noted research into potential brain benefits of GLP-1 medications needs more research, but are optimistic about the future of these drugs in boosting brain health.
Professor David Hunter at UTHealth in Houston (not involved in the review) commented: ‘Decades of research into Alzheimer’s disease have shown that inflammation is a key step in disease pathology… Alzheimer’s disease begins with amyloid plaques, and microglia play a role in the steps that lead to brain cells dying.”
Professor Hunter expected UTHealth’s own EVOKE trial will announce results on the use of semaglutide for patients with early Alzheimer’s in the autumn of 2025.
