A recent study published in the Journal of Gerontology: Medical Sciences rekindled scholarly interest in metformin, a medicine used for decades to treat type 2 diabetes. Researchers discovered that postmenopausal women with diabetes who took metformin had a considerably higher likelihood of living to be 90 or older than those who took another type of diabetes medication known as sulfonylureas.

The work, coordinated by Dr Aladdin H. Shadyab and Dr Andrea LaCroix of the University of California, San Diego, adds to a growing corpus of research into gerotherapeutics—drugs that may halt biological ageing and delay the onset of age-related disorders. 

The researchers used data from the Women's Health Initiative (WHI), one of the largest and longest-running women's health studies in the United States, to examine the health outcomes of women aged 50 to 79 over multiple decades. Their significant finding: those on metformin had a 30% lower probability of dying before the age of 90 than those receiving sulfonylureas. 

Importantly, the study did not compare metformin users to a placebo group; thus, the researchers emphasised that the findings indicate a substantial connection rather than direct proof of cause and effect. But they remain optimistic. As Dr Shadyab stated, "Our findings suggest metformin may offer health benefits beyond blood sugar control, including the possibility of extending life." 

Metformin works by enhancing the body's insulin sensitivity and lowering excess sugar produced by the liver. However, experts believe it may also alter critical biological processes associated with ageing, such as inflammation, cell damage, and metabolism. 

This potential effect of metformin has piqued the curiosity of experts researching "healthy aging"—not simply surviving longer but living better. According to the National Institute on Ageing, gerotherapeutics such as metformin have the potential to prevent or delay the onset of various chronic illnesses, including heart disease, dementia, and cancer. 

Dr. Nir Barzilai, head of the Institute for Ageing Research at Albert Einstein College of Medicine and not participating in the WHI trial, has long pushed for metformin's ability to tackle ageing itself. "We need to stop treating diseases one at a time," he remarked in a previous interview. "Ageing is the common cause." 

The WHI, a federally funded program established in the 1990s, enrolled nearly 161,000 women aged 50–79 across the United States. It has resulted in significant improvements in understanding heart disease, osteoporosis, and breast cancer in women. More than 42,000 of its participants—now a unique resource for ageing research. 

With over 2,400 published studies, WHI continues to influence public health guidelines and medical practice around the world. The recent metformin trial expands on its legacy by illustrating how existing drugs may assist older in unexpected ways. 

Despite the positive results, experts concur that more research is necessary. Future clinical trials should directly test metformin in healthy older individuals who do not have diabetes to determine whether the medicine can actually delay ageing and prevent age-related disorders. One such study, TAME (Targeting Ageing with Metformin), has been in the works for several years but has yet to commence due to financing constraints. 

In the meantime, physicians advise prudence. "People should not start taking metformin just to live longer," Dr LaCroix stated. "This study focused on elderly women with diabetes." It is not a universal anti-ageing pill—at least not yet." 

Still, experts are intrigued by the possibility that a widely available, low-cost medicine could help people live not only longer but also healthier lives.