Again, showing the lack of effects glutamine has on the immune system....
1: J Sports Sci. 2004 Jan;22(1):115-25. Related Articles, Links
Exercise, nutrition and immune function.
Gleeson M, Nieman DC, Pedersen BK.
School of Sport and Exercise Sciences, Loughborough University, Loughborough LE11 3TU, UK.
m.gleeson@lboro.ac.uk
Strenuous bouts of prolonged exercise and heavy training are associated with depressed immune cell function. Furthermore, inadequate or inappropriate nutrition can compound the negative influence of heavy exertion on immunocompetence. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction. An adequate intake of iron, zinc and vitamins A, E, B6 and B12 is particularly important for the maintenance of immune function, but excess intakes of some micronutrients can also impair immune function and have other adverse effects on health. Immune system depression has also been associated with an excess intake of fat. To maintain immune function, athletes should eat a well-balanced diet sufficient to meet their energy requirements. An athlete exercising in a carbohydrate-depleted state experiences larger increases in circulating stress hormones and a greater perturbation of several immune function indices. Conversely, consuming 30-60 g carbohydrate x h(-1) during sustained intensive exercise attenuates rises in stress hormones such as cortisol and appears to limit the degree of exercise-induced immune depression.
Convincing evidence that so-called 'immune-boosting' supplements, including high doses of antioxidant vitamins, glutamine, zinc, probiotics and Echinacea, prevent exercise-induced immune impairment is currently lacking.
Am J Physiol Cell Physiol. 2001 Oct;281(4):C1259-65. Related Articles, Links
Click here to read
Effect of glutamine supplementation on exercise-induced changes in lymphocyte function.
Krzywkowski K, Petersen EW, Ostrowski K, Kristensen JH, Boza J, Pedersen BK.
Copenhagen Muscle Research Centre and Department of Infectious Diseases, Rigshospitalet, 2200 Copenhagen N, Denmark.
The purpose of this study was to investigate the possible role of glutamine in exercise-induced impairment of lymphocyte function. Ten male athletes participated in a randomized, placebo-controlled, double-blind crossover study. Each athlete performed bicycle exercise for 2 h at 75% of maximum O(2) consumption on 2 separate days. Glutamine or placebo supplements were given orally during and up to 2 h postexercise. The trial induced postexercise neutrocytosis that lasted at least 2 h. The total lymphocyte count increased by the end of exercise due to increase of both CD3(+)TCR alpha beta(+) and CD3(+)TCR gamma delta(+) T cells as well as CD3(-)CD16(+)CD56(+) natural killer (NK) cells. Concentrations of CD8(+) and CD4(+) T cells lacking CD28 and CD95 on their surface increased more than those of cells expressing these receptors. Within the CD4(+) cells, only CD45RA(-) memory cells, but not CD45RA(+) naive cells, increased in response to exercise. Most lymphocyte subpopulations decreased 2 h after exercise. Glutamine supplementation abolished the postexercise decline in plasma glutamine concentration but had no effect on lymphocyte trafficking, NK and lymphokine-activated killer cell activities, T cell proliferation, catecholamines, growth hormone, insulin, or glucose. Neutrocytosis was less pronounced in the glutamine-supplemented group, but it is unlikely that this finding is of any clinical significance.
This study does not support the idea that glutamine plays a mechanistic role in exercise-induced immune changes.
