Whey Protein Improves Cognitive Function inHigh-Stress Subjects

Whey Protein Improves Cognitive Function inHigh-Stress Subjects

MAASTRICHT, The Netherlands--Dietary protein richin alpha-lactalbumin--a whey protein with a high tryptophan content--was shownto improve mental performance in stress-vulnerable subjects, according toresearchers from the University of Maastricht who published their results in theJune issue of the American Journal of Clinical Nutrition (75, 6:1051-6,2002) (www.ajcn.org). Researchers recruited 23high stress-vulnerable subjects and 29 low stress-vulnerable subjects for adouble blind, placebo-controlled, crossover study. All subjects completed amemory-scanning task after consuming a diet enriched with either alpha-lactalbuminor sodium caseinate (control). Researchers analyzed blood samples to measure theeffect of the dietary manipulation on the ratio of plasma tryptophan to the sumof the other large neutral amino acids (Trp-LNAA ratio). A significant increasein the plasma Trp-LNAA ratio was noted after consumption of the alpha-lactalbumindiet compared to the control diet. In addition, memory scanning improvedsignificantly in the high stress-vulnerable subjects. Because an increase in theplasma Trp-LNAA ratio is considered an indication of increased brain serotoninfunction, researchers concluded that the active diet improved cognitive functionin stress-vulnerable subjects via increased brain tryptophan and serotoninactivity.