A new study suggests that weight loss injections could almost halve the risk of developing obesity-related cancers, with benefits that appear to go beyond weight reduction alone.
The research compared patients who took weight loss drugs—specifically GLP-1 receptor agonists—with those who underwent bariatric surgery. Both groups showed similar rates of obesity-related cancers, even though surgery generally leads to greater weight loss.
The study found that GLP-1 medications were associated with a 41% lower risk of developing obesity-linked cancers compared to surgery, suggesting the drugs may have additional protective effects.
Dr. Yael Wolff Sagy, co-lead author from Clalit Health Services in Tel Aviv, said the results indicate that the drugs may have a direct anti-cancer effect. “We do not yet fully understand how GLP-1s work,” she said, “but the findings add to growing evidence that weight loss alone does not explain all the benefits these medications offer.”
Obesity is the second leading cause of cancer in the UK, responsible for more than one in 20 cancer cases, according to the NHS.
Researchers analyzed electronic health records of patients with obesity or type 2 diabetes, none of whom had a history of cancer. All had been treated with first-generation GLP-1 receptor agonists. Over an average follow-up period of seven and a half years, 298 patients developed obesity-related cancers, with breast, bowel, and womb cancers being the most common.
Cancer occurred in 150 out of 3,178 people who had bariatric surgery, and in 148 out of 3,178 people who took GLP-1 medications. This was despite the greater average weight loss seen in the surgery group.
Dr. Dror Dicker, co-lead author from Hasharon Hospital at Rabin Medical Centre, said the protective effects of the drugs likely come from “multiple mechanisms, including reducing inflammation.” He noted that newer, more effective GLP-1 drugs could offer even stronger protection, but warned that further research is needed to ensure these medications don’t raise the risk of other types of cancer.
Professor Naveed Sattar, an expert in cardiometabolic medicine at the University of Glasgow, urged caution in interpreting the results. He noted that because the study was observational and not a clinical trial, it cannot definitively prove cause and effect.
The study was published in the journal eClinicalMedicine and presented at the European Congress on Obesity in Malaga. It comes as the NHS considers making weight loss injections more widely available through pharmacies at the standard prescription charge of £9.90.
