Metformin, India’s Go-To Diabetes Pill, May Also Slow The Body’s Ageing Clock: Study

Metformin, one of India’s most widely prescribed and inexpensive diabetes drugs, may have benefits that extend far beyond blood sugar control.

Now, a new Indian study suggests the decades-old, inexpensive drug may be doing something far more than lowering blood sugar — it could be slowing down the biological clock inside human cells.

The 24-week randomised controlled trial, conducted at the Fortis C-DOC Centre of Excellence for Diabetes, Metabolic Diseases and Endocrinology in New Delhi, found that metformin significantly lengthened telomeres — the protective caps at the ends of chromosomes that shorten as cells age — in North Indian adults with prediabetes.

The findings were published in the journal Mechanisms of Ageing and Development.

“Aging

isn’t just a ticking clock—it’s a biological trajectory we can rewrite. Our new research shows metformin can boost cellular longevity pathways in just 24 weeks, independent of blood sugar changes,” Dr Anoop Misra, executive chairman of Fortis C-DOC Hospital for Diabetes and Allied Sciences and one of the authors of the study, told News18.

“Proof that the future of medicine isn’t just treating illness, but actively extending our healthspan!”

What Did The Study Do?

Research led by Dr Surya Prakash Bhatt, Shivam Pandey and Dr Anoop Misra screened 322 people with prediabetes and enrolled 127 of them, aged 30 to 60 years, who had impaired glucose tolerance.

Participants were randomly assigned to receive either metformin 500 mg twice daily or a matching placebo (dummy pill) for six months, alongside identical diet and lifestyle counselling for both groups.

Neither the participants nor the laboratory staff assessing the results knew who was on the drug and who was on the placebo — a design meant to rule out bias. Of the 127 enrolled, 112 completed the trial — a high retention rate of 88.2 per cent.

“We found that Metformin, a medicine already used safely for decades to control diabetes, may also help protect our cells from ageing — almost like slowing down an internal clock,” said Dr Surya Prakash Bhatt, another author of the study and also a research scientist at AIIMS, New Delhi.

“What’s exciting is this happened even in people whose blood sugar didn’t change much, suggesting the benefit goes beyond just diabetes control. But these are early findings, so more research is needed before we can say this changes how the drug should be used.”

What Did The Study Find?

The metformin group showed a striking 29.6 per cent elongation in telomere length over six months, compared with just 4.4 per cent in the placebo group — a difference the researchers described as highly significant.

The team measured leukocyte telomere length and telomerase activity, along with the activity of four genes linked to longevity and cellular stress.

A telomere is the protective cap at the very end of a chromosome — the structure inside our cells that carries our DNA.

The easiest way to understand it is to think of the plastic tip at the end of a shoelace, the part that stops the lace from fraying. Telomeres do something similar for our chromosomes — they stop the ends from unravelling or getting damaged every time a cell divides.

Telomerase activity, which helps rebuild these protective caps, rose by 39.3 per cent in the metformin group, while it declined slightly in those on placebo.

Two longevity-linked genes also responded differently across the groups. SIRT1, a gene associated with cellular repair and longevity, rose by about 30 per cent in the metformin arm compared with roughly 4 per cent with placebo.

mTOR activity, a pathway involved in cell growth and ageing, also rose substantially in the metformin group even as it fell in the placebo group — a result the authors flagged as unexpected, since metformin is conventionally understood to suppress mTOR activity rather than raise it.

Two other genes tracked in the study, p66Shc and p53, showed similar modest increases in both groups, with no meaningful difference between metformin and placebo.

These cellular changes occurred even though metformin’s effect on blood sugar did not last through the full study period. Fasting glucose improved at three months in the metformin group, but the difference had faded by six months, while blood sugar control, measured through HbA1c levels, showed no significant difference between the groups at any point. Body weight and body composition also remained largely unchanged in both arms. The researchers said this indicates that metformin’s effect on cellular ageing markers works independently of its blood-sugar-lowering action.

Why Does This Matter For India?

Asian Indians are known to develop prediabetes and type 2 diabetes earlier and at lower body weights than other populations, and studies by the same research group have previously linked shortened telomeres to obesity in Indian women with abnormal blood sugar. The authors argue that a population already prone to faster metabolic and cellular ageing stands to benefit the most from an intervention that appears to work on both fronts.

The researchers were careful to flag the limitations of their own findings. They noted that a nearly 30 per cent increase in telomere length within just six months is larger than what pharmacological interventions typically produce and cautioned that this should be treated as an early molecular signal rather than proof of how fast telomeres are truly lengthening. They also called for the mTOR finding to be confirmed through further protein-level testing, and for future trials to run for at least a year in more diverse groups of patients, including those who already have diabetes or other health conditions.

In the paper, the authors write that the results provide compelling evidence that metformin beneficially modulates cellular ageing pathways, independent of minor changes in glycaemia and with no changes in body weight.

According to Dr Praveen Ramachandra, consultant – endocrinology and human metabolism at Sparsh Hospital, Yehlenka, “The 29.6 percent gain in telomere length over a period of 24 weeks is remarkable and unusual for a drug. However, the randomized trial is promising especially when one considers that the placebo group had just a 4.4 percent gain in telomere length.”

“A large, rapid change in telomere length must be taken with some caution as this measurement can vary due to differences in the assay method used as well as changes in the composition of immune cells in circulation and other biological variables. Nevertheless, these results will definitely raise more interest in metformin apart from being used for managing blood sugar levels.”