Nilsson, M., Holst, J. J., and Bjorck, I. M. Metabolic effects of amino acid mixtures and whey protein in healthy subjects: studies using glucose - equivalent drinks. (webmd.com)
Their findings show that children and adults thrive on diets based on a single starch; and they grow healthy and strong.11, 12 Furthermore, no improvement is obtained by mixing plant foods or supplementing with amino acid mixtures to make the combined amino acid pattern look more like that of flesh, dairy, or eggs.12 (For a thorough discussion of human protein needs see The McDougall Plan, New Win Publishers.) (nealhendrickson.com)
The women who were impacted — with a lowering of their mood — used a tryptophan - deficient amino acid mixture and not collagen. (everywomanover29.com)