Wednesday, July 6, 2011
Colostrum as an Ergogenic Aid?
Colostrum: Is there an Athletic Use for It?
Bovine colostrum (BC), like human colostrum, is produced by cows within the first 4 days after giving birth and contains various growth, antimicrobial and immunity factors that are meant to support the immunity and intestinal development of the calf (Crooks, Cross, Wall, & Ali, 2010). Colostrum is generally freeze dried and sold as a powder for human consumption. Some of the immune and growth factors are immunoglobulins, insulin growth hormones, cytokines, lactoferrin, transforming growth factors, gonadotrophin-releasing hormone, lutenizing hormone-releasing hormone and glucocorticoids; most of which are suggestive of improving an athlete’s immunity, gastrointestinal health and negate parameters that may become compromised during high intensity or increased bouts of training (Shing et al., 2009). The quality of BC is determined by when the colostrum was produced and extracted from the cow. The best quality of BC is captured on the first day of birth and contains higher concentrations of growth and immune factors when compared to human colostrum (Shing et al., 2009). Colostrum supplementation has grown in the athletic world since the first documented research study was performed in 1997 which looked at the effects of BC on serum immunoglobulins, IGF-1 and explosive/power performance in the athletic population (Shing, Hunter, & Stevenson, 2009). Despite its growing popularity in athletics there still remains a small amount of conclusive evidence that bovine colostrum promotes any increases in muscular strength and lean body mass, enhancements of certain factors within the immune system that would promote greater resistance to illnesses, or that it can improve digestive tract health (Shing et al., 2009). Currently the World Anti-Doping Agency does not list colostrum as a banned substance, but it does list Insulin-like Growth Factor 1 (IGF-1) that aids in the mediation of growth hormones and protein synthesis as a banned substance (World Anti-Doping Agency, 2011). Athletes may be at risk of testing positive for IGF-1 supplementation since BC may increase the serum levels of IGF-1 in humans; however, several studies show that there is no significant increase in IGF-1 levels in humans that have used BC in short durations, so chances of producing a false positive for IGF-1 is considered small (Shing et al., 2009).
Currently the bulk of research delves into the immunity and performance benefits of BC supplementation with athletes. Athletes that train at moderate to high levels of intensity for durations of >1.5 hours can greatly compromise their immune system by increasing the numbers of leukocytes (white blood cells) and inflammatory response cytokines while decreasing the number of natural killer cells by depressing their cytotoxic activity (Carol, Witkamp, Wichers, & Mensink, 2011). This decrease in immunity function can create an open window (3-24 hr) where athletes have an increased risk to infection, but can last for 1 – 2 weeks after a strenuous event (Carol et al., 2011), and can be exacerbated if the athlete suffers from a poor diet, lack of rest, is experiencing psychological stress or is in an unfamiliar place (Crooks, Wall, Cross, & Rutherford-Markwick, 2006). This period in depressed immunity can be caused by intense training and may be reversed through rest, but many athletes, especially competitive athletes, do not have the time to rest. The majority of the illnesses associated with high intensity or long duration training are upper respiratory infections (URIs) and often result in periods of underperformance and lost training time which are thought to be related to an impaired mucosal defense (Crooks et al., 2010). Currently BC considerations are being considered for the treatment and prevention of infections and diseases of the gastrointestinal tract and also for use in conjunction with the ingestion of NSAIDs to decrease the damage that NSAIDs can cause on the stomach lining (Carol et al., 2011), but there are no current medical practices involving the use of colostrum in patients. Colostrum is also proving very successful in the treatment of distal colitis, as well as, decreasing the recurrence of diarrhea in children (Shing et al., 2009).
Three studies that involved the use of BC for supplemental use in athletes focusing on immunity benefits were chosen for this ergogenic aid summary. These studies all looked at the concentrations of salivary immunoglobulin A (s-IgA) in the saliva or other concentrations of immunoglobulins in the blood and the amount of days reported with URIs (Carol et al., 2011; Crooks et al., 2010 & Crooks et al., 2006). One other side effect of intense or long duration training has on the immune system is a reduction in s-IgA causing a temporary deficiency in antibodies that can lead an athlete to be susceptible to infection from foreign pathogens, for this reason an increase in s-IgA concentrations in saliva could be considered proof that BC supplementation can improve immune function in athletes (Crooks et al., 2006).
In a study looking at BC supplementation in swimmers both the BC athletic cohort and the placebo cohort maintained both diet and exercise logs so that poor diet or overtraining could be ruled out as factors for URIs, they were also told to log days with symptoms of URIs (Crooks et al., 2010). The BC group ingested 25 g of BC and the placebo group ingested 25 g of powdered skim milk with cold water twice a day (total of 50 g) for a period of 10 wks (Crooks et al., 2010). Saliva was captured at baseline (prior to the start of the study), 4 and 10 weeks during the study and then again 2 wks after the study to measure for plasma immunoglobulin concentrations (Crooks et al., 2010). There were no significant differences in energy intake or training between the two cohorts, but the BC group reported fewer URIs than the placebo group. This difference was increased in the later portion of the study (Crooks et al., 2010). Crooks et al. (2010) considered the differences in URIs insignificant, but did state that the decrease in reported URIs could demonstrate the influence that BC had on the immune system. There was also no significant increase in immunoglobulin concentrations in the saliva. The influence of BC on the reduction of reported URIs in the colostrums group might be due to how BC interacts with the intestinal mucosal lining in the colostrums group (Crooks et al., 2010). Intense exercise can illicit the release of lipopolysacchrides (LLS) which can initiate a strong immune response along with stimulating the production of cytokines, and it is possible that BC supplementation may enhance the intestinal immune homeostatic mechanisms during moments of physical stress (Crooks et al., 2010). It was noted that BC supplementation most likely stimulated the bioactives within the intestinal linings during the homeostic state rather than presenting a secondary affect in the immunity response (Crooks et al., 2010).
Ten well trained athletes participated in a 2 x 19 day double blind study where each participant served as both the placebo group and the BC group. In this study the athletes logged their diets, exercise regimen and wrote down any symptoms associated with URIs (Carol et al., 2011). Carol et al. (2011) hypothesized that the effects of BC on the immune system would be enhances through short-term intense exercise by depleting the body’s glycogen stores. The athletes would maintain their regular exercise programs during the supplementation program which employed the ingestion of 12.5 g of colostrum or skim milk powder twice a day (total of 25 g) starting on day 8 of the program and stopping on day 18 (Carol et al., 2011). On day 17 the athletes performed a graded exercise test to exhaustion on cycle ergometers where the workload was increased until exhaustion happened, exhausted was defined as the inability to maintain a pace of 50 rpm (Carol et al., 2011). On day 18 the athletes returned in a fasted state to perform a 1.5 hr endurance test to evoke sufficient stress to the body to suppress the immunity system while under a glycogen depleted state (Carol et al., 2011). Blood sample taken during the study showed an increase in white blood cell activity, no significant increases in immunoglobulin concentrations, and no significant difference in cytokine levels between the two groups though cytokine were elevated in both groups after the glycogen depletion trial (Carol et al., 2011). Cytokine IL-6 was elevated which promotes the production of cytokines IL-10, IL-1ra and cortisol which can contribute to the suppression of the natural killer T-cells thus allowing infection to occur (Carol er al., 2011). Increases in these immunity variables are generally associated with damaged tissue and can result in the feeling of sickness (Crooks et al., 2006). It was noted the BC did not have any effect on the immune variables that were being investigated in this study. All of the elements that were expected to increase within the human immunity response did indeed increase and this was proof that the studies exercise protocol was enough to induce the stress reflex that the body can exhibit during bouts of stressful exercise, however the study failed to show that supplementation of BC would alter any of the immunity variables thus preventing post exercise immune suppression (Carol et al., 2011). This study did not look at s-IgA concentrations or secretion rate to determine immunity response and there was no mention of reported URIs. This might be because an URI episode was defined by lasting more than 2 consecutive days.
Crooks et al. (2006) looked at recreational marathon runners focusing on immune variables and BC supplementation. In particular Crooks et al. (2006) was looking at s-IgA concentration levels and secretion rates in amateur runners. Thirty-nine men and women were chosen for this study and were all members of Auckland YMCA Marathon club. The athletes consumed 26 g of either skim-milk powder or colostrums during the course of a 16 week period; training and wellness diaries were maintained to look at energy sources and to record any URIs (Crooks et al., 2006). Five saliva samples were taken to determine s-IgA concentration during the course of the study and saliva samples were discarded if there was not an ample amount of saliva or if the subject appeared to be dehydrated or having fasted since this can falsely elevate s-IgA levels (Crooks et al., 2006). All participants were expected to compete in the New Zealand Marathon, and of the 39 that started the study one male withdrew due to illness, one was breast feeding, one was training for her first marathon, four others did not compete in the marathon due to injury or other factors, and two others competed in an earlier marathon. This study was not very well controlled and this may have affected the results. There was a median increase in s-IgA levels in the colostrum group of 79% and in the placebo group 16% and this was considered to be very significant (Crooks et al., 2006). URIs were lower in the colostrum group, but the totals were not different enough from those in the placebo group to deem significant. This matches the results shown in multiple studies where URIs are considered a determinant in the validity of BC supplementation and the immunity of athletes (Shing et al., 2009). Despite the insignificance of URIs between the two cohorts it is possible that colostrum did play a role in fewer reported URIs by the colostrums group.
There is minimal existing evidence that BC is useful in preventing illness in athletes. Though several studies have reported that there is a decrease in URIs in athletes consuming BC the numbers are insignificant (Crooks et al., 2006). This is also true when examining the results of studies looking at increase muscle growth and lean mass, however, there is some conclusive evidence that BC can be beneficial to exercise performance following several days of intense training (Shing et al., 2009). In one study 30 male endurance runners showed an improvement in performance during a second bout of exercise while supplementing with BC (Crooks et al., 2006). Colostrum also appears to decrease fatigue and increase vigor in some athletes after a 20 g/d supplementation period of 8 weeks (Shing et al., 2009). Overall colostrum appears to be safe and with minimal to no side effects. The general daily supplement dose for clinical trials is 10-15 g and with studies involving athletes the dose is raised to 20-60 g (Carol et al., 2011). All of the studies that were researched were within the athletic dosage range. Crooks et al. (2006) reported that six female runners in the BC group of their study reported stomach problems associate with the supplement, five of these runners noted that the symptoms went away with time. It was not noted what those stomach problems were. Long term use may result in mild side effects that can include anxiety, logorrhea and insomnia, but this should reside within a short time frame of approximately 3 – 4 days (Zhion.com, 2009). No long term side effects were noted in any of the studies or literature reviews that I researched. This might be because studies on athletes generally are not long term. The longest study that I researched lasted 16 weeks. None of the other studies noted any side effects or issues with supplementation. It must be noted that athletes who are lactose intolerant or express a milk allergy should refrain from the use of BC as a supplement (Shing et al., 2009). More research needs to be done to determine if there is an athletic ergogenic benefit.
Carol, A., Witkamp, R. F., Wichers, H. J., & Mensink, M. (2011). Bovine colostrums supplementation’s lack of effect on immune variables during short-term intense exercise in well-trained athletes. International Journal of Sports Nutrition and Exercise Metabolism, 21(2), 134-145.
Crooks, C., Cross, M. L., & Ali, A. (2010). Effect of bovine colostrums supplementation on respiratory tract mucosal defenses in swimmers. International Journal of Sports Nutrition and Exercise Metabolism, 20(3), 224-235.
Crooks, C. V., Wall, C. R., Cross, M. L., & Rutherfurd-Markwick, K. J. (2006). The effect of bovine colostrums supplementation on salivary IgA in distance runners. International Journal of Sports Nutrition and Exercise Metabolism,16(1), 47-64.
Shing, C. M., Hunter, D. C., & Stevenson, L. M. (2009). Bovine colostrums supplementation and exercise performance. Sports Medicine, 39(12), 1033-1064.
World Anti-Doping Agency. (2011). Substances and methods prohibited at all times. Retrieved from the World Anti-Doping Agency website: http://www.wada-ama.org/en/World-Anti-Doping-Program/Sports-and-Anti-Doping-Organizations/International-Standards/Prohibited-List/The-2011-Prohibited-List/Prohibited-at-All-Times/
Zhion.com. (2009). Colostrum benefits side effects and composition. Retrieved from the Zhion.com website: http://www.zhion.com/Supplements/Colostrum.html