Prescription tablets already available on the NHS may mimic some benefits of exercise by helping to control weight and protect the heart even in those who are inactive.
Metformin, which is taken by nearly three million patients with type 2 diabetes, costs as little as 2p per pill and has previously been linked with reducing the risk of cancer.
And leading scientists now believe it could also raise levels of a molecule released when we exercise – helping to control blood sugar and boost cardiovascular health in those unable to stay active.
The study by researchers at the University of Miami Miller School of Medicine, published in the journal EMBO Molecular Medicine, examined the effects of the drug in 29 men diagnosed with prostate cancer.
‘From a clinical standpoint, seeing a metabolic signal that mirrors what we associate with intense exercise was striking,’ said lead author Dr Marijo Bilusic, a medical oncologist.
‘For patients whose treatments or symptoms limit physical activity, that kind of effect could be especially meaningful.’
Researchers analysed blood samples to measure how the pill had an effect on N-lactoyl-phenylalanine, or Lac-Phe – a molecule which is produced when the body is exercising.
Known to spike after intense physical activity, Lac-Phe has also been linked to appetite suppression and weight loss.
Metformin could mimic the beneficial effects of exercise providing hope for thousands of patients, a striking new study has found
And the results uncovered that while metformin did not appear to treat prostate cancer itself, it did raise Lac-Phe levels in the patients – without the need for any actual exercise.
It opens the door to further research into the drug’s potential, particularly for cancer patients who often experience fatigue that limits their ability to train.
‘Metabolism is involved in everything cells do,’ said David Lombard, Sylvester researcher and professor of pathology and laboratory medicine at the Miller School.
‘These findings suggest Lac-Phe may be a very informative signal for understanding how metformin affects metabolism in prostate cancer patients.’
Dr Bilusic added: ‘The result isn’t a new cancer biomarker, but a clearer understanding of how a widely used drug may support metabolic health during prostate cancer treatment – an outcome that matters to patients and clinicians alike.’
The research team said more work was needed on the subject, but said their findings ‘reminds us cancer care isn’t only about targeting tumours’.
Priyamvada Rai, professor of radiation oncology at the Miller School, said: ‘Supporting metabolic health can influence how patients tolerate treatment and how they feel over time, even if it doesn’t directly change tumor growth.
‘This study was an opportunity to investigate molecular pathways that can be therapeutically activated for better outcomes to treatments that induce metabolic stress.’
Earlier studies have linked metformin to a lower risk of oesophageal cancer – and suggest the drug could also help guard against prostate cancer.
It is typically prescribed for diabetes when diet and exercise alone have not been enough to control blood sugar levels.
The NHS say metformin is also used to improve fertility in women with polycystic ovary syndrome – a condition which can cause irregular periods, enlarged ovaries and excess male hormones which can lead to facial hair.
It has been gaining attention as a possible cancer-fighting drug, with research suggesting it can slow the growth of cancer cells.
The pill lowers levels of insulin, a hormone which helps malignant cells multiply.
