Bovine colostrum supplementation’s lack of effect on immune variables during short-term intense exercise in well-trained athletes

Journal Title (Medline/Pubmed accepted abbreviation): Int J Sport Nutr Exerc Metab
Year: 2011
Volume: 21
Number: 2
Page numbers: 135-145
doi (if applicable): N/A

Summary of Background and Research Design

Background: Prolonged (> 1.5 hr), continuous, moderate to high intensity exercise performed in a fasted state affects both the innate and adaptive immune systems, creating a period of ~ 3 to 24 hours postexercise when athletes are vulnerable to infections, especially upper respiratory tract infection (URTI). Bovine colostrum, the first milk made after parturition, is a good source of carbohydrates, protein, fat, minerals, and growth and immune factors, and is being investigated as a nutritional supplement for its potential to enhance immune function. Results on the potential of bovine colostrum in sport nutrition are unclear, and only limited information is available on exercise-induced alterations in immune variables.

Hypothesis/purpose of study: The purpose of the study was to investigate the effect of bovine colostrum supplementation on several immune variables following short-term intense exercise in well-trained, glycogen-depleted athletes.

Subjects: Nine well-trained male athletes completed the study (mean age, 27.3 ± 4.5 yr; weight, 73.0 ± 5.7 kg; body mass index, 21.9 ± 1.6 kg/m2; maximal power output [Wmax], 364.4 ± 25.1 W). Training frequency ranged from 3 to 7 times/week, and training volume ranged from 5 to 12 hours/week.

Experimental design: Double-blind, placebo-controlled, crossover design

Treatments and protocol: Total study duration was 2 x 19 days, with a washout period of ~ 2.5 weeks. During the presupplementation period (first 7 days), subjects kept a log of dietary habits, training performance, and illness symptoms. The supplementation period was 10 days, and subjects consumed 12.5 g bovine colostrum or skim milk powder (placebo) twice a day mixed in a glass of cold milk or buttermilk. Following supplementation, subjects completed a glycogen-depletion trial (Day 17) and an endurance cycling trial (Day 18; 1.5 hours at 50% Wmax), to evoke a substantial amount of stress on the immune system. Blood samples were taken before the glycogen-depletion trial (T0), before (T1) and after (T2) the endurance trial, and ~ 22 hours after exercise cessation (T3), and were analyzed for neutrophil, lymphocyte, serum immunoglobulin, and cytokine counts.

Summary of research findings
  • Energy intake, measured on 2 separate days during the run-in period, was higher in the colostrum condition vs placebo (P < .01).
  • Several immune factors were affected by intense exercise.
    • Plasma cortisol levels increased over time, reaching the highest level at T2 and remained elevated at T3 compared with baseline values (P < .001).
    • Neutrophil counts were increased at T2 and dropped below starting levels at T3 (P < .001).
    • A significant time effect was seen for interleukin (IL)-6, IL-10, IL-1 receptor agonist, and C-reactive protein, with levels being higher at T2 (P < .05).
  • Other immune factors including circulating immunoglobulins, interferon gamma, IL-1 alpha, IL-8, and tumor necrosis factor-alpha did not show a significant time effect.
  • There was no difference between colostrum and placebo in any of the postexercise immune factors investigated.

Interpretation of findings/Key practice applications

Study results were consistent with the notion that intense exercise affects several markers of the immune system; however, 10 days of supplementation with bovine colostrum (25 g/day) did not have any different effects on the immune factors investigated compared with skim milk powder. Data from this study and others demonstrate that bovine colostrum supplementation does not offer benefit in preventing postexercise changes in immune variables after short-term intense exercise during periods of normal physical activity. However, the effects of bovine colostrum on intense exercise during periods of increased physical stress (eg, training camp) cannot be ruled out and warrant further study.
Google Tracking Google Plus Tracking Twitter Tracking