Influence of the level of dietary lipid intake and maximal exercise on the immune status in runners.
Chronic exercise and high fat diets are associated with immune suppression. This study compares cellular immune responses at rest and after maximal exercise in runners after eating diets comprised of 17% low fat (LF), 32% medium fat (MF), and 41% high fat (HF) (4 wk each). VO2max increased significantly from the 17% to 41% fat diet. The leukocyte cell counts were significantly increased after exercise. In men, significantly higher proliferative response to phytohemagglutinin (PHA) (P < 0.004) was observed with MF diet, while response to pokeweed mitogen (PWM) was significantly decreased by MF and HF diets. The number of CD8+ (suppressor) T cells was significantly higher in men and exercise increased it significantly, while CD4+ (helper) T cells were not affected. Natural killer cells number was significantly increased 2.5 fold by exercise and with increase in dietary fat. The production of IL-2 by peripheral blood mononuclear cells was significantly higher in men (P < 0.0001) and increasing dietary fat significantly increased IL-2 production (P < 0.001). In men, exercise decreased the level of the proinflammatory cytokines (IL-1, IL-6 and TNF-alpha), whereas in women, with the exception of MF diet for IL-6, exercise had no effect. This study indicates that short, intense bouts of exercise in runners training 40 miles.wk-1 have mixed effects on the immune system. A high percentage of fat intake (41%) did not have any deleterious effects on the immune system of the well-trained runners.
Venkatraman
J T
JT
Department of Oral Biology, State University of New York at Buffalo 14214, USA. jtv@acsu.buffalo.edu
Rowland
J A
JA
Denardin
E
E
Horvath
P J
PJ
Pendergast
D
D
D000328:Adult; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology; D002455:Cell Division / Q000187:drug effects; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D006801:Humans; D007108:Immune Tolerance; D007111:Immunity, Cellular / Q000187:drug effects / Q000502:physiology*; D007375:Interleukin-1 / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007694:Killer Cells, Natural / Q000166:cytology; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008055:Lipids / Q000008:administration & dosage* / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012146:Rest / Q000502:physiology; D012420:Running / Q000502:physiology*; D012737:Sex Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D004041:Dietary Fats; D007375:Interleukin-1; D007376:Interleukin-2; D015850:Interleukin-6; D008055:Lipids; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D014409:Tumor Necrosis Factor-alpha