Racetams have proven effects on healthy adults. [Do you want to know more?]. There's a scaled effect which is notable, but most adults over 30 will benefit from them (i.e. the 'smarter / less damaged your systems are' the less benefit you get).
Do you really not have access to common papers? This might be a question of me assuming common access to information where there is none.
Or, think of it this way ~ unless you're living in a pristine environment (which most of you aren't), then they'll help you. Most humans are swimming in a whole sea of chemicals [airborne, ingested] and bacterial processes that you're not aware of. Heck, every human being's weight is 1Kg (ish) of non-human DNA and complex ecosystems.
Yep, that's right: you're a huge ecosystem of your own, revel in it. So take off 1kg off the scale, that's other beasties at play.
Ye Gods, most of you are firing off megadeath levels of antibacterials, chromosome damaging chemicals, metal-based-nasties and so forth just by getting ready in the morning.[1] Your brain chemistry is a whole lot more complex ~ and although we're getting there on understanding it, we've a while to go.
But, the Racetams have so far proven entirely benign, and helpful. They should be given to everyone by deafult, if we're in the realms of fluoridating water supplies.
[1] No, I like science. I love science. We all love it. Still doesn't change the fact that processes like decaffeinated coffee production had stupidly large amounts of cancer producing drugs in them until recently. Or DDT.