My wife and I were debating the use of supplements yesterday.  We got on to NAD+ and 🤔:

People with high X (cell health) have high Y (NAD+).

If we measure Y to determine X, does supplementing Y raise X (cell health) or does it just increase Y (the thing we measure -> NAD+). 

Does anyone know? 

cc: @bryanjohnson

Independent Power Networks @Aston // astonlabs.co.

From observational data or observational studies alone, you cannot know whether an association between two things is because of a direct causal link between them or not. So then you wouldn’t know whether changing one variable would actually affect the other.

That’s why it’s important to do randomized controlled trials, which is a form of active experimentation. With those, you can get evidence that suggests whether there is a direct causal link or not and whether changing one variable (e.g. taking a medication or supplement) would affect the other (e.g. longevity or improved health outcomes).

This makes sense.  My question is if there’s a way measure something like biological age directly?  Or do we measure NAD+ levels and say, “your biological is 30 because your NAD+ levels are that of a 30 year old”.  But actually, our biological age is the same, we just fooled ourselves with NAD+ supplements?