An article published by Onken and others in Aging Cell 27th November 2021 tries to research this issue.
Metformin, the most commonly prescribed anti-diabetes medication, has multiple reported health benefits such as:
- Lowering the risks of cardiovascular disease and cancer
- Improving cognitive function with age
- Extending survival in diabetic patients and in several animal models
- Promoting youthful physiology and lifespan.
Due to its longevity and health effects, metformin is now the focus of the first proposed clinical trial of an anti-aging drug – the targeting aging with metformin programme TAME.
Genetic variation will likely influence outcomes when studying metformin health effects in human populations.
The author’s tried to test for metformin impact in diverse genetic backgrounds, and measured lifespan and health span effects of metformin treatment in three worm species- Caenorhabditis species, representing genetic variability greater than that between mice and humans.
They showed that metformin increases medium survival in three strains, the
C. elegans but not in C. briggsae and C. tropicalis strains.
In the C. briggsae strain metformin either had no impact on survival or decreased lifespan.
In the C. tropicalis strain metformin decreased medium survival in a dose dependent manner.
However, they showed that metformin prolonged the period of youthful vigour in all
C. elegans strains and in two C. briggsae strains but metformin had a negative impact on the locomotion of C. tropicalis strain.
This trial demonstrated that metformin can be a robust promoter of healthy aging across different genetic backgrounds, but that genetic variation could determine whether metformin has a positive, neutral, or negative lifespan health span impact.
These results underscore the importance of tailoring treatment to individuals when testing for metformin health benefits in a diverse human population.
In humans, clinical trials in populations with type 2 diabetes show that metformin increases overall survival, lowers the incidence of cancer and cardiovascular disease, and improves cognitive function.
However, there is no evidence as yet that metformin can promote health or increase lifespan in healthy populations.
Locomotor ability, a measure of mobility, which was taken as an indicator of health, revealed that in some genetic backgrounds health span would be increased without an increase in medium or maximal lifespan.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed