In a potentially landmark discovery for dementia care, a widely used NHS weight loss injection could reduce the progression of Alzheimer's disease by up to half, according to promising new British research.
A New Hope in the Fight Against Dementia
The drug in question is liraglutide, marketed under the brand name Saxenda. Already prescribed to thousands of NHS patients with a body mass index (BMI) over 30, it works by improving blood sugar control and suppressing appetite. It belongs to the same class of GLP-1 agonist medications as the better-known semaglutide (Ozempic, Wegovy).
Now, a team led by Professor Paul Edison, a neuroscience expert at Imperial College London, has found compelling evidence that this daily injection could also be a powerful weapon against Alzheimer's. Their phase 2b trial suggests it may slow cognitive decline and the loss of brain volume by roughly 50%.
"Our findings provide some of the strongest evidence yet that GLP-1 treatments could modify the disease process in Alzheimer's disease," said Professor Edison. He highlighted that the drug's existing approval and safety profile could fast-track its use for dementia, stating, "We are not starting from zero."
How the Groundbreaking Trial Worked
The study, published in the journal Nature Medicine, involved 169 people with mild to moderate Alzheimer's, with an average age of 71. They were split into two groups: 72 received liraglutide, while 82 were given a placebo.
Over 12 months, brain scans revealed a striking difference. Patients on liraglutide experienced about half the rate of brain volume loss compared to the placebo group. Furthermore, the drug showed an 18% greater beneficial effect on cognition.
The researchers believe liraglutide's benefits may stem from its ability to reduce neuroinflammation and the accumulation of toxic tau protein in the brain. These proteins, along with amyloid, form the plaques and tangles thought to drive Alzheimer's symptoms.
Contrasting Results and Future Implications
This hopeful news arrives just a week after trial results indicated that semaglutide—a related drug—did not significantly slow Alzheimer's progression. That announcement caused a 12% drop in share value for manufacturer Novo Nordisk, which also makes Saxenda.
Professor Edison's team cautions that their 12-month study may be too short to confirm long-term benefits definitively. "Further studies are necessary to fully establish the effectiveness of this drug," they wrote. However, the results pave the way for a major phase 3 trial programme.
The potential to repurpose an existing, widely available drug offers a significant advantage in the urgent battle against dementia. With around 944,000 people in the UK and 7 million in the US living with dementia—and Alzheimer's affecting six in ten of them—a new therapeutic strategy that doesn't solely target amyloid is a crucial development.
Saxenda is available on the NHS for weight management via specialist referral, with common side effects including digestive issues and sleep trouble. While primarily a metabolic treatment, its newly discovered neuroprotective effects could revolutionise dementia care in the years to come.
