For centuries, humanity has dreamed of extending life, a quest once limited to alchemy and folklore. While we haven't found a "philosopher's stone," modern science has consistently shown that eating less (dietary restriction) can prolong life in many lab animals. But what if there was a way to gain these benefits without constant dieting? Recent …
For centuries, humanity has dreamed of extending life, a quest once limited to alchemy and folklore. While we haven’t found a “philosopher’s stone,” modern science has consistently shown that eating less (dietary restriction) can prolong life in many lab animals. But what if there was a way to gain these benefits without constant dieting?
Recent groundbreaking research is shining a spotlight on compounds that mimic the biological effects of dieting, with two leading candidates: rapamycin and metformin. A new study has revealed compelling evidence that rapamycin prolongs life almost as consistently as eating less, while metformin’s effects are less clear.
The Gold Standard: Eating Less
Since a study nearly a century ago found that laboratory rats eating less outlived their well-fed counterparts, dietary restriction has been the “gold standard” for achieving a longer life. However, sticking to a strict, permanent diet can be challenging and, if taken to extremes, potentially unhealthy.
This led scientists to investigate drugs that could potentially offer the same benefits without the drawbacks of continuous dieting.
Introducing Rapamycin: A Promising Lead
- Origins: Rapamycin was first discovered in the 1970s in bacteria found in the soil of Easter Island (Streptomyces hygroscopicus).
- How it Works: It’s a powerful immunosuppressant, currently used to prevent organ-transplant rejection. Critically, it works by blocking a molecular switch that signals to cells when nutrients are abundant, effectively mimicking a state of nutrient scarcity—similar to what happens when you eat less.
Metformin: Less Clear Benefits
- Origins: Metformin is derived from a compound found in French lilac and is widely used to control blood sugar in Type 2 Diabetes.
- Longevity Effects: While both rapamycin and metformin are involved in how the body senses nutrients, the new study, which pooled results from 167 studies across eight vertebrate species (from fish to monkeys), found that metformin did not show a clear, consistent benefit in prolonging life.
The Findings: Rapamycin Close Behind Dietary Restriction
The comprehensive analysis confirmed that eating less still yields the clearest and most consistent results for life prolongation across all animal species. However, rapamycin came in a close second, showing a remarkable ability to extend lifespan. The effects of eating less were consistent for both sexes and whether the diet involved smaller portions or intermittent fasting.
Why This Matters for Us
While aging isn’t classified as a disease, it’s a major risk factor for many conditions, including cancer and dementia. If we can slow down the underlying aging process, it could lead to:
- More years of quality life.
- Lower healthcare costs as the global population ages.
Early Signs for Humans, But Not Yet a Prescription
It’s important to note a few key considerations:
- Variability: There was some variation in experimental results, with a few studies even showing a reduced lifespan.
- Animal Studies: Most of the strong evidence comes from studies on mice and rats, which, while sharing many genes with humans, are not identical to us.
- Side Effects: Rapamycin can have side effects, including repressing immunity and reproduction. Researchers are now exploring lower, milder doses to see if they can achieve the benefits without these drawbacks.
Encouragingly, an ongoing human trial with low, intermittent doses of rapamycin has shown positive effects on indicators of “healthspan” (the period of life spent in good health). A human trial for metformin’s anti-aging effects is also underway, with results expected in a few years.
For now, no one should be asking their doctor for rapamycin prescriptions for anti-aging. However, this research demonstrates that targeting specific molecular pathways can mimic the benefits of eating less. The challenge ahead is to develop therapies that can make us healthier for longer, without compromising our quality of life – or our enjoyment of life’s simple pleasures, like a slice of chocolate cake!
Stay informed about the latest scientific breakthroughs in health and longevity!
Ivimey-Cook, E. R., Z. Sultanova, and A. A. Maklakov. 2025. “ Rapamycin, Not Metformin, Mirrors Dietary Restriction-Driven Lifespan Extension in Vertebrates: A Meta-Analysis.” Aging Cell e70131. https://doi.org/10.1111/acel.70131.
Book a Consultation
It’s easy and free!
