A weight-loss drug could help slow the loss of brain volume in people with Alzheimer’s disease, according to a small study. Liraglutide, which can also be prescribed for diabetes, is typically taken as an injection once a day. Trial results published at the Alzheimer’s Association international conference in the US suggest the drug, also known as Saxenda, could slow decline in memory and thinking in people with the disease. The number of people living with dementia globally is forecast to nearly triple to 153 million by 2050, and experts say this presents a rapidly growing threat to future health and social care systems. “This research provides hope that more options for changing the course of the disease are on the horizon,” said the chief science officer of the Alzheimer’s Association, Dr Maria Carrillo. “We are in an era of unprecedented promise, with new treatments in various stages of development that slow or may possibly prevent cognitive decline due to Alzheimer’s disease.” The trial studied 204 patients in the UK. Half received liraglutide, made by Novo Nordisk, and the other half a placebo. The study did not meet its primary endpoint, or main goal, which was change in the cerebral glucose metabolic rate, an assessment of brain function. It did meet the secondary endpoints. The drug appeared to reduce shrinking in the parts of the brain that control memory, learning, language and decision-making by nearly 50% compared with the placebo. Researchers led by experts from Imperial College London said that after 12 months of treatment, the drug appeared to reduce cognitive decline in participants by as much as 18%. Tests examining memory, comprehension, language and spatial orientation revealed that those who took the drug had a “statistically significant slowing of cognitive decline” after a year compared with those who had the placebo drug. Experts said much larger studies were required to confirm the findings. The study lead, Paul Edison, a professor of science at Imperial College London, said: “The slower loss of brain volume suggests liraglutide protects the brain, much like statins protect the heart. “While further research is needed, liraglutide may work through various mechanisms, such as reducing inflammation in the brain, lowering insulin resistance and the toxic effects of Alzheimer’s biomarkers amyloid-beta and tau, and improving how the brain’s nerve cells communicate.” Dr Sheona Scales, the director of research at Alzheimer’s Research UK, said: “Being able to repurpose drugs already licensed for other health conditions could help accelerate progress and open up new avenues to prevent or treat dementia-causing diseases, such as Alzheimer’s. “This new research shows that people with early-stage Alzheimer’s taking liraglutide had a slower decline in memory and thinking, and less brain shrinkage, over 12 months, compared to placebo. “However, the study was carried out in a small group of people. Larger trials are now happening to see whether drugs like liraglutide are effective at slowing down the progression of Alzheimer’s disease.” The trial was not sponsored by Novo Nordisk. However, the company is testing another of its weight-loss drugs, semaglutide – sold as the diabetes drug Ozempic and the obesity drug Wegovy – in thousands of patients with early Alzheimer’s. Its two trials began in 2021 and results are expected in 2025.