Does coffee activate mTOR?
Coffee does not activate mTOR. Caffeine actually inhibits mTOR, and in humans this mechanism has not yet been directly tested. Whether that inhibition produces any practical benefit in daily life remains unknown.
Caffeine inhibits mTOR, it does not activate it. In multiple cell studies, caffeine reduced the activity of mTOR and the proteins downstream of it. That inhibition was strong enough to completely block even insulin, a powerful activator of mTOR. The effect has been demonstrated in nerve cells, bone and gastric cancer cells, and immune cells.
Because mTOR normally suppresses autophagy, the inhibition by caffeine has an indirect consequence: cells begin clearing more waste products. This mechanism was observed in cell studies and confirmed in one animal model using vascular wall cells. In cancer cells, mTOR inhibition also led to increased programmed cell death. This is of interest to cancer research, but all findings come from cell and animal models. Whether this effect is clinically relevant in humans has not been investigated.
There is one exception that complicates the picture. In a mouse study, coffee as a beverage actually did activate mTOR in skeletal muscle tissue, and the mice gained more muscle mass and muscle strength. This seems contradictory, but coffee contains hundreds of compounds besides caffeine. Muscle tissue responds differently from cancer cells, and mice are not humans. On the basis of this single animal study, you cannot conclude that coffee activates mTOR in human muscle tissue.
One safety signal deserves mention: in cell culture research, a very high caffeine concentration, combined with alcohol, amplified damage to nerve cells through further mTOR inhibition. The concentrations used in those experiments are far above what is reached with normal coffee consumption, but it does indicate that mTOR inhibition by caffeine can have unwanted effects in specific circumstances.
The answer rests almost entirely on cell culture studies and one mouse study. There are no studies in humans that directly measure how coffee or caffeine affects mTOR activity in the body. The cell and animal results are reasonably consistent with one another across multiple cell types, but the translation to humans has not been made.
What is mTOR and why does it matter in ageing?
mTOR is a switch in your cells that determines when they grow and when they clean themselves up. In ageing, that switch is set too high more often, and research shows that lowering that activity has a beneficial effect on long-term health.
Does coffee help prevent type 2 diabetes?
Large population research shows that regular coffee drinkers develop type 2 diabetes considerably less often, but whether coffee itself is the cause remains uncertain.
What are mitochondria, and can you make them younger or more energetic?
Exercise is the only demonstrably effective way to improve mitochondria; for supplements such as NMN or urolithin A, the evidence in humans is still too thin to support a recommendation.
How does metformin work in your body?
Metformin lowers blood sugar primarily by causing the liver to produce less new glucose, without the risk of dangerously low blood sugar. Exactly how all the pieces of the mechanism fit together is not yet fully clear.
What is AMPK and how do you activate it (through fasting or exercise)?
Exercising with little carbohydrate in your system is the best-supported way to activate AMPK. Working out on an empty stomach combines the effects of low carbohydrate availability and exercise.
Does metformin help with weight loss?
Metformin helps with weight loss, but the effect is modest: expect a few kilograms, not a dramatic transformation. Lifestyle changes work better in the short term, but weight loss with metformin remains stable over the long term. Discuss it with your doctor if you want to know whether it suits your situation.