US Edition
Weight-loss jabs can cut the risk of dementia, a study suggests.
Scientists at the University of Florida said that semaglutide in particular, whose brand names include Wegovy and Ozempic, showed promise in cutting the risk of conditions that impair memory and thought processes.
Experts said the study called for further research to shed light on how these drugs affect the brain.
A study by the University of Oxford in 2024 suggested that Ozempic could cut the risk of dementia by half.
Academics in the US analysed data from type 2 diabetes patients who were taking either GLP-1 receptor agonists (GLP-1RAs), which work by reducing food cravings, or sodium-glucose cotransporter-2 inhibitors (SGLT-2i) reducing the amount of glucose the kidneys re-absorb and allowing it to pass out of the body in urine.
GLP-1RAs is a class of medication that includes semaglutide as well as the brand Rybelus, which is taken as a tablet.
Wegovy was approved to tackle weight loss on the NHS in 2023, while Ozempic and Rybelus are available as treatments for type 2 diabetes.
Statistically significant results
The study included the health records of 396,963 people over 50 from January 2014 to June 2023.
All had type 2 diabetes but no diagnosis of Alzheimer’s disease and related dementias (ADRD).
Researchers compared those on GLP-1RAs, SGLT-2i and other, second-line glucose-lowering drugs.
The analysis found that “both GLP-1RAs and SGLT2is were statistically significantly associated with decreased risk of ADRD compared with other GLDs, and no difference was observed between both drugs”.
It was found that among the GLP-1RAs, “semaglutide seems to be promising in reducing the risk of ADRD”.
“This finding is particularly intriguing given the existing research on semaglutide’s neuroprotective properties,” researchers added.
Dr Leah Mursaleen, the head of clinical research at Alzheimer’s Research UK, said: “We don’t know yet why these medicines may be offering a protective effect and will need more research to understand how they are affecting the brain.”
She added that while the findings were “interesting”, it was important to consider if other factors might be influencing results such as overall health, income or education.
Researchers in Ireland have suggested GLP-1RAs are “associated with a statistically significant reduction in dementia”.
Their study analysed 26 clinical trials involving almost 165,000 patients to determine if drugs such as SGLT2is and GLP-1RAs, as well as diabetes medications metformin and pioglitazone, led to a reduction in risk of dementia or cognitive impairment.
It found most drugs “were not associated with an overall reduction in all-cause dementia” although GLP-1RAs were associated with a “statistically significant reduction”.
Both studies have been published in the journal Jama Neurology.
Track people for longer
Dr Richard Oakley, the director of research and innovation at Alzheimer’s Society, said: “Whilst both of these studies found a link between GLP-1RAs and reduced dementia risk, only one found SGLT2is, another class of diabetes drug, were also associated with a reduced risk.
“More research is needed by tracking people for longer, especially as they get older.”
Prof Tara Spires-Jones, the director of the Centre for Discovery Brain Sciences at the University of Edinburgh, said the data was “encouraging”.
“But even within these two strong studies, there are slightly conflicting results over SGLT2is, highlighting the need for further research,” she said.
“It is important to note that these drugs do have side effects and they are not guaranteed to prevent dementia.
“The studies had important limitations including a relatively short follow-up time.”
Masud Husain, a professor of neurology and cognitive neuroscience at the University of Oxford, said: “These analyses suggest that GLP-1 receptor agonists, particularly semaglutide, might reduce the risk of developing dementia in people with type 2 diabetes.
“The wider question of whether such drugs might also be protective against dementia in people who don’t have diabetes is a really intriguing one, and the focus of several ongoing clinical trials,” she added.