Blockbuster weight loss jabs relied on by millions of slimmers could slash the risk of developing dementia, two major studies have suggested.
Semaglutide — the powerful ingredient behind Wegovy and Ozempic — has long been hailed a monumental breakthrough in the war on obesity and type 2 diabetes.
Now, US researchers who tracked almost 400,000 people, said the ingredient was more effective at curbing the onset of the memory-robbing condition than other diabetes medications.
Experts also said the findings add to a growing body of evidence that suggests diabetes is a risk factor for dementia.
But they cautioned that further research was still vital to further prove the link and said they couldn’t be sure why the medicines, collectively known as GLP-1 agonists, may offer this protective effect.
Professor Tara Spires-Jones, director of the Centre for Discovery Brain Sciences at the University of Edinburgh and president of the British Neuroscience Association, who wasn’t involved in the study, said the data was ‘encouraging’.
However, she added: ‘It is important to note that these drugs do have side effects and that they are not guaranteed to prevent dementia.
‘The study had important limitations including a relatively short follow up time.
Semaglutide and tirzepatide — the powerful ingredients behind Wegovy, Ozempic and Mounjaro — have long been hailed a monumental breakthrough in the war on obesity and type 2 diabetes
‘Future work will be important to understand how risk factors like diabetes and obesity increase risk of dementia to develop effective treatments and prevention strategies.’
In the study, scientists at the University of Florida analysed the health records 396,963 people over the age of 50 with type 2 diabetes.
None had a diagnosis of dementia and were either taking GLP-1 medication or sodium-glucose cotransporter-2 inhibitors (SGLT-2i) which work by reducing the amount of glucose the kidneys re-absorb allowing it to pass out of the body in urine.
Over a follow-up of a 10 years they found ‘both GLP-1RAs and SGLT2is were statistically significantly associated with decreased risk’ of dementia compared to other medication.
Writing in the journal Jama Neurology, they added that among GLP-1RAs specifically, ‘semaglutide seems to be promising in reducing the risk of Alzheimer’s disease and related dementias (ADRD)’.
They said: ‘This finding is particularly intriguing given the existing research on semaglutide’s neuroprotective properties.’
Responding to the study, Dr Leah Mursaleen, head of clinical research at Alzheimer’s Research UK, said: ‘The results from this study support the growing evidence that GLP-1RA and SGLT-2 inhibitors medicines may reduce dementia risk.
‘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.’
Around 900,000 Britons are currently thought to have the memory-robbing disorder. But University College London scientists estimate this will rise to 1.7million within two decades as people live longer. It marks a 40 per cent uptick on the previous forecast in 2017
But she added that while the findings are ‘interesting’, it is important to consider if other factors might be influencing results like overall health, income or education.
It comes as separate research from scientists in Ireland today suggested that GLP-1RAs were also ‘associated with a statistically significant reduction in dementia’.
The study analysed 26 clinical trials involving almost 165,000 patients to determine if drugs like 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 was associated with a statistically significant reduction in all-cause dementia.’
Alzheimer’s is the most common cause of dementia in the UK.
Recent analysis by the Alzheimer’s Society estimates the overall annual cost of the dementia to the UK is £42billion a year, with families bearing the brunt.
An ageing population means these costs — which include lost earnings of unpaid carers — are set to soar to £90billion in the next 15 years.
Around 944,000 people in the UK are thought to be living with dementia, while the figure is thought to be around 7million in the US.
Alzheimer’s disease is the most common cause of dementia. The disease can cause anxiety, confusion and short-term memory loss
It is thought to be caused by a build-up of amyloid and tau in the brain, which clump together and from plaques and tangles that make it harder for the brain to work properly.
Eventually, the brain struggles to cope with this damage and dementia symptoms develop.
Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.
Previous studies have estimated that around 40 per cent of all dementia cases could be prevented with lifestyle changes.
This includes healthier diets, increased exercise, drinking less alcohol, preventing head injury and using hearing aids.
Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.
