In this episode of the Nutrition Facts Podcast, Dr. Michael Greger explores the science of mTOR, a key enzyme linked to ageing, disease, and longevity. He unpacks how suppressing mTOR with drugs like rapamycin may slow ageing, extend lifespan, and improve health—but not without risks. Drawing from animal and early human studies, Greger discusses the promise, potential dangers, and why diet might offer a safer way to regulate this powerful biological pathway.

Key Points:

Suppressing mTOR with the drug rapamycin has shown promise in slowing ageing and extending lifespan across multiple species—but potential side effects, such as immune suppression, mean it’s not without risk.

• What Is mTOR and Why It Matters: mTOR (mechanistic Target of Rapamycin) is a cellular growth regulator that fuels ageing by pushing cells to grow without slowing down. In early life it drives development, but in adulthood, unregulated mTOR activity may accelerate ageing and disease.
• Rapamycin- A Dirt-Derived Drug That Extends Life: Originally discovered in soil from Easter Island, rapamycin blocks mTOR and has been shown to extend lifespan in every animal tested—including mice and potentially dogs—while improving heart, brain, and immune function in ageing models.
• Risks vs. Rewards in Humans: While small trials suggest low-dose rapamycin might enhance immunity in older adults, the drug is still linked to serious side effects like infections, especially at higher doses. Larger, long-term human trials are lacking due to low profit incentives and safety concerns.
• Beyond Pills: Natural Ways to Lower mTOR: Until safer strategies are confirmed, suppressing mTOR through lifestyle—such as calorie restriction, plant-based diets, and intermittent fasting—may offer a safer, evidence-backed approach to healthy ageing.