I discuss melatonin's effects on sleep & its safety; I segue into the general benefits of sleep and the severely disrupted sleep of the modern Western world, the cost of melatonin use and the benefit (eg. enforcing regular bedtimes), followed by a basic cost-benefit analysis of melatonin concluding that the net profit is large enough to be worth giving it a try barring unusual conditions or very pessimistic safety estimates.
Full essay: http://www.gwern.net/Melatonin
No. Your excerpt was a poor exposition of the standard precautionary principle I regard as entirely useless.
Reading your link now, I have even less reason to pay attention to it. It's a random press release about a presumably small unreplicated animal study in a species I don't know to be particularly germane to humans (eg. chimps) about changes of unclear importance in a body system with no human analogues ("In birds, switching off GnRH causes the gonads -- testes and ovary -- to shrink as part of the birds' yearly cycle.") with doses potentially high enough to be completely irrelevant to human supplementation (injecting melatonin?). I haven't even read the study!
Combine all the conditionals here (the smallness and lack of replication alone knocks down the chance this means anything about anything to well under 50%), and I don't see why I would update at all (not being an AI or anything which can represent degrees of belief with 64-bit floats).
If anything, I think this sort of study is a good example of why animal studies should be ignored in discussing supplements.
Good points.
Have there been any meta-analyses of how well supplement studies on animals tend to transfer to humans?