Not nonsense at all, simply a fact. :-
http://www.13.waisays.com/zombie.htm
From the above:-
"These opioid peptides cause physical dependence in the young, to make sure it wants to drink lots of mother’s milk. Also, it makes the young sleep enough."( 8 ) Koldovsky, O., Search for the role of milk borne biologically active peptides for the suckling. J.Nutr. 1989 / 119 (11) / 1543-1551. , Buts, J.P. Bioactive factors in milk. Arch. Pediatr. 1998 / 5 (3) / 298-306.
More to the point, I was not specifically stating that dairy was bad in that post, I merely pointed out a more likely explanation for why milk is seen as a cure for insomnia, rather than the tryptophan explanation.
"Scientific understanding of the biochemistry and pharmacology of casomorphins is incomplete"
There is extremely little research on this matter, as far as I can see this is the only one ever made, by Koldovsky. Aswell as there are plenty of other foods that contain opioid peptides, such as spinach.
So these claims are based on nothing, really. And I can just discredit this right here and now, because I have never ever felt sluggish after eating dairy products. And seeing as I've drunk up to 3 liters a day, I'm sure I would've felt a profound effect by now.