Use of GLP-1 weight loss-drugs – such as semaglutide (Wegovy) and tirzepatide (Mounjaro) – is associated with reduced risk of a wide range of conditions including Alzheimer’s disease and dementia, a large study has concluded.

US researchers analysed the use of GLP-1 receptor agonist drugs in health records from 2.4 million people with diabetes and also found a reduced risk of several substance use disorders; clotting disorders; respiratory conditions including COPD; and inflammatory bowel disease.

Overall, they found a lower risk of 42 health conditions associated with use of the group of drugs for people taking them for diabetes compared with those who took other medicines.

Reporting in Nature Medicine, they created an Atlas of conditions with a reduced risk which included deep vein thrombosis and heart attack. But it also includes conditions where the risk seemed to be heightened in those taking of GLP-1 receptor agonists.

They found an increased risk of 19 health outcomes including symptoms of gastrointestinal conditions such as nausea and vomiting, abdominal pain, low blood pressure, fainting and arthritis as well as pancreatitis and kidney conditions.

The analysis was done on data from the US Department of Veterans Affairs and the researchers stressed this was an observational study and did not prove causality.

Study leader Dr Ziyad Al Aly Director of the Clinical Epidemiology Center at Washington University School of Medicine in St Louis said GLP-1RA drugs act on receptors that are expressed in brain areas involved in impulse control, reward and addiction, ‘potentially explaining their effectiveness in curbing appetite and addiction disorders’.

‘These drugs also reduce inflammation in the brain and result in weight loss; both these factors may improve brain health and explain the reduced risk of conditions like Alzheimer’s disease and dementia.’

But he added the magnitude of associated benefits was modest.

‘However, the modest effect does not negate the potential value of these drugs, especially for conditions where few effective treatment options exist, for example, dementia.

‘This may also imply that these drugs are most beneficial when used in conjunction with other interventions, such as lifestyle changes or other medications.’

Professor Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow, said some of the suggested benefits identified in the study had been confirmed in randomised controlled trials such as reduced risk of heart attack and stroke.

But most would others require future assessment to confirm or refute.

‘The same goes for suggested risks, some of which make clear sense (eg, more nausea and vomiting) and have been seen in trials, but many others have not, and findings could simply reflect unmeasured confounding.’

He added: ‘Fortunately, large scale randomised trials with GLP-1RA-based therapies that yield greater weight loss are ongoing and several will report out in the next 1-4 years. Such trials will lead us much closer to the truth.’

A version of this article was first published by our sister title Pulse