Influence of level of dietary lipids and exercise on immune status in athletes

High levels of dietary fat and exercise training have been associated with poor immune status. This study compared the cellular immune responses at rest and after maximal exercise in runners (7 men and 7 women. 35±3 years) after eating diets comprised of 1 5%, 30% and 45% fat (4 wks each). Blood was drawn from athletes prior to and immediately after \O2 rnax test and cellular immune functions were determined in peripheral blood mononuclear (PBMN) cells. VO? max increased from 15 to 45% fat diet. The leucocyte cell counts significantly increased 82 and 113% after exercise. When the cells were cultured in the presence of lectins, proliferative response was decreased. Lymphocyte surface markers, CD3 (pan) and CD8 (suppressor) for T cells were significantly influenced by gender and exercise while CD4 (helper) cells was not. The number of natural killer cells was significantly increased by exercise from 3.9±0.8 to 7.9+1.? for women and 4.1±0.6 to 9.4±1.3 for men with significant effect of increased dietary fat. Based on in vitro production of cytokines by PBMN cells stimulated with lectins, increased dietary fat had significant effect on IL-2 and IL-1, IL-6 and TNFu while gender effect was seen only m IL-2. These data support the conclusion that running training (40 miles/week) and high % of fat intake (45%) do not compromise the immune system. (Supported by an Educational Grant from Mars, Inc.).