Whole blood and mononuclear cell glutathione response to dietary whey protein supplementation in sedentary and trained male human subjects.
Sedentary male subjects (n=9) on a controlled diet were fed two doses (0.8 or 1.6 g/kg body mass) of a whey protein isolate (WPI), in addition to an isocaloric placebo; blood samples were drawn over a 4-h period and glutathione concentration determined. There was no effect of the supplementation at either level over the 4-h sampling period. The effects of a WPI supplemented diet on glutathione concentrations in whole blood as well as peripheral mononuclear cell populations were also investigated over a 6-week period in male subjects (n=18) involved in arduous aerobic training; blood was collected prior to and following a 40 km simulated cycling trial. The aerobic training period resulted in significantly lower glutathione concentrations in whole blood, an effect that was mitigated by WPI supplementation. A significant increase in mononuclear cell glutathione was also observed in subjects receiving the WPI supplement following the 40 km simulated cycling trial.
Middleton
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N
Faculty of Agriculture, Food and Nutritional Sciences, University of Alberta, Edmonton, Alberta, Canada.
Jelen
P
P
Bell
G
G
D000328:Adult; D000596:Amino Acids / Q000032:analysis; D001642:Bicycling / Q000502:physiology; D004044:Dietary Proteins / Q000494:pharmacology*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D015444:Exercise / Q000502:physiology; D005978:Glutathione / Q000097:blood*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008894:Milk Proteins / Q000494:pharmacology*; D000067816:Whey Proteins
D000596:Amino Acids; D004044:Dietary Proteins; D008894:Milk Proteins; D000067816:Whey Proteins; D005978:Glutathione