Doubt cast over metformin claims

UK researchers analysed the results of 13 trials representing 50,000–65,000 person-years of follow-up, with their conclusions contradicting other meta-analyses, which found metformin users had a 31–33% reduced risk of cancer.

“In contrast to observational and laboratory evidence, we found no statistically significant beneficial effect of metformin on cancer outcomes,” the authors wrote.

“Metformin had little effect on overall mortality compared with other active diabetic therapies, and a statistically non-significant 10% reduction in mortality compared with placebo or usual care.”