Active ingredient in Ozempic, Wegovy may reduce risk of Alzheimer's disease: Study

The active ingredient found in popular medications for Type 2 diabetes and weight loss, including Ozempic and Wegovy, may reduce the risk of Alzheimer's disease, a new study published Thursday finds.

Researchers from the Case Western Reserve University School of Medicine in Cleveland, Ohio, looked at three years of electronic records of almost 1 million patients with Type 2 diabetes, including those prescribed semaglutide.

Semaglutide falls under a class of medications known as glucagon-like peptide-1 receptor agonists, or GLP-1s, which mimic the GLP-1 hormone that is produced in the gut after eating.

It can help produce more insulin, which reduces blood sugar and therefore helps control Type 2 diabetes. It can also interact with the brain and signal a person to feel full, which -- when coupled with diet and exercise -- can help reduce weight in those who are overweight or obese.

The team found that compared to seven other anti-diabetic drugs, semaglutide helped significantly lower the risk for Alzheimer's disease, including other types of GLP-1s.

Semaglutide was associated with a 70% reduced risk when compared with insulin and 40% reduced risk when compared with other GLP-1 drugs, according to the study.

Women experienced an even lower risk for Alzheimer's with semaglutide when compared to men, at about 80% compared to 50%, respectively.

However, women in the study were younger and more likely to have obesity or depression. They were also less likely to have heart disease, which may have led to their lower risk.

About 120,000 Americans die from Alzheimer's disease in the U.S. each year, and it is currently the seventh-leading cause of death nationally, according to the Centers for Disease Control and Prevention.

While getting Type 2 diabetes under control may already lower the risk for Alzheimer's disease, there may be additional dementia risk reduction for semaglutide, according to Rong Xu, lead researcher and professor of biomedical informatics at Case Western.

Semaglutide is considered to be "the most potent of the GLP-1s being that it has the greatest effect at hitting the receptor," and, of the GLP-1s, it also produces the greatest weight loss, said Dr. Louis Aronne, the director of the Comprehensive Weight Control Center at Weill-Cornell Medical Center.

The greater potency of semaglutide may be why it has a stronger protective effect against Alzheimer's.

Xu told ABC News that although there is no cure for Alzheimer's disease, there are several risk factors including Type 2 diabetes and obesity that may be controlled.

"If we can address those risk factors, then we can prevent Alzheimer's disease," she said. "So, for semaglutide, there's some preclinical evidence showing that this medication has neuro-protective effects and is also anti-inflammation, which can address a lot of risk factors associated with Alzheimer's disease."

This means GLP-1 medications may not only lower blood sugar to reduce the risk for Alzheimer's disease, but they may also play a role in reducing neuro-inflammation.

"GLP-1 receptor agonists mitigate neuroinflammation, they mitigate oxidative stress, (and) they mitigate a number of things which occur systemically but also in the brain," Nigel Greig, principal investigator at the National Institute on Aging, told ABC News.

However, the exact mechanism behind how GLP-1 medications reduce Alzheimer's risk is unknown so more research is needed, according to Xu.

"This is only (an) association, we cannot prove causality," Xu said. "So, it's not recommended to say people prescribed this medication can treat or prevent Alzheimer's disease."

"But this study can help people who already have Type 2 diabetes or obesity and are high risk for Alzheimer's disease, it maybe can provide some evidence for medication selection," she added.

For future research, Xu said she wants to examine if semaglutide can also lower the risk of other neurodegenerative diseases, including Parkinson's disease and Lewy body dementia.

"GLP-1s provide benefit over and above weight loss alone. We are just beginning to understand the benefits of these drugs beyond weight loss alone," said Aronne.

Itohan Omorodion, MD, MPH, is an internal medicine resident at George Washington University Hospital and a member of the ABC News Medical Unit.