My point is that most drugs don't work this well for your disease, if you are diseased. If this result were mechanistically true, then we could instantly prolong human lifespan dramatically.
But my point is that when you're healthy, the mortality risk is so low, that it doesn't take much to make it even lower.
Even more impressive result, exercise reduces all cause mortality by 40%:
> Using a large nationally representative sample of US adults, we found that those who engaged in both aerobic and muscle strengthening activities consistent with the recommended 2018 physical activity guidelines for Americans showed a reduced risk of all cause mortality (40% reduction).
But that doesn't follow. It's conditional. More accurate follow would be "instantly prolong human lifespan dramatically AS LONG AS YOU DON'T GET DISEASED"
Example: having a fire extinguisher in your house decreases risk of losing your house in a fire by 30% before a fire. But if your house is on fire I bet it's much much lower. There are two different populations, two different distributions.
Luckily, there is no signal for harm from coffee, so we can randomize a bunch of healthy people and see if there is an effect. Personally, I'd want to see a higher quality of evidence before spending my time on it, but if people believe it, this is one of the most important studies in the history of human health waiting to be written.
