Obesity drugs could lead to new ways to protect the brain

Drugs used to treat obesity may also help protect the brain. In a review published in Science, researchers outline how a better understanding of these drugs’ effects could lead to new treatments that protect memory and other important cognitive abilities. 

Drugs such as semaglutide and tirzepatide are already used to treat obesity and type 2 diabetes, but they also influence biological processes important for brain function. At the invitation of Science, researchers at the University of Gothenburg and the University of Copenhagen assessed the available evidence. 

Animal studies show that GLP-1 drugs can affect memory and learning, but findings in humans have been mixed. Studies of patient records have linked GLP-1 treatment to a lower risk of dementia in people with type 2 diabetes, although they cannot establish whether the drugs themselves account for the difference. 

In Novo Nordisk’s clinical trials EVOKE and EVOKE+, semaglutide did not slow disease progression in patients with early Alzheimer’s disease, despite changes in several biological markers of the disease. 

Potential benefits for the brain 

These results do not rule out the possibility that the drugs could protect brain function in other patients. People with obesity or type 2 diabetes may experience difficulties with attention, planning, and processing speed. These problems are often linked to metabolic and vascular health and may therefore respond better to treatment. 

Stina Börchers is the first author of the review and a researcher affiliated with the University of Gothenburg and the University of Copenhagen. 

“We need to find out whether these treatments can help people with obesity or diabetes preserve their cognitive abilities, particularly if treatment begins before cognitive problems become established. It is also important to identify which patients might benefit,” says Stina Börchers. 

Toward new treatments 

The researchers want to understand whether the drugs’ potential effects on the brain result from improved metabolism, direct effects on the brain, or a combination of both. 

Christoffer Clemmensen is the senior author of the review and a research group leader at the University of Copenhagen. 

“Obesity medicines are becoming increasingly sophisticated, offering new opportunities to understand how metabolic regulation influences brain function. By disentangling the direct and indirect effects of these drugs on the brain, we may ultimately be able to develop treatments specifically aimed at preserving cognitive function,” says Christoffer Clemmensen. 
The researchers are calling for clinical trials that track memory and other cognitive abilities from the start of treatment. They also emphasize the importance of monitoring older and frail patients, for whom rapid weight loss and loss of muscle mass could impair physical function and reduce the potential benefits of treatment.