Nutrition Performance By Anssi Manninen Colostrum: The Ultimate Source of Protein? Athletes engaged in heavy training need more protein than sedentary people.1,2,3 Protein supplements may be a convenient means for some busy athletes to secure additional protein in the diet. Many of these products contain high-quality protein, such as milk or egg protein; they provide a balanced mixture of protein, carbohydrate and fat for additional calories; and they may also contain supplemental vitamins and minerals. It’s important to emphasize that these supplements should be used as an adjunct to an otherwise balanced nutritional plan, not as a substitute. Milk proteins are commercially available as whole milk proteins, caseinates and whey proteins. Milk protein is approximately 80 percent caseinate and 20 percent whey protein. Recently, bovine colostrum protein has been marketed as an ultimate source of protein for athletes. Colostrum is the first milk secreted by cows after giving birth and is a rich source of protein, carbohydrates, fats, vitamins, minerals and biologically active components such as antimicrobial molecules, immunoglobulins and growth factors. Recent data from our laboratory suggest that colostrum protein has a higher Protein Efficiency Ratio (PER) than calcium caseinate.4 Further, there is some evidence suggesting colostrum supplementation may increase lean body mass,5 improve time trial performance in cyclists,6 enhance recovery during endurance exercise,7 improve sprint performance in hockey players,8 enhance buffer capacity in female rowers,9 increase peak anaerobic power,10 and enhance resistance to development of upper respiratory track infection.11 Colostrum and Lean Body Mass The purpose of a recent study by Dr. Jose Antonio and colleagues was to determine the effect of eight weeks of colostrum supplementation on body composition and exercise performance in active men and women.5 Subjects were randomly assigned to either a placebo (whey protein) group or a colostrum group (20 grams/day). Each subject participated in aerobic and heavy resistance training at least three times per week. Body composition was assessed via dual x-ray absorptometry (DEXA) analysis. Treadmill time to exhaustion, one repetition maximum strength (bench press), and the total number of repetitions performed during one set to exhaustion at a submaximal load for the bench press (50 percent and 100 percent of body weight for women and men, respectively) were ascertained. The whey protein group experienced a significant increase in body weight (mean increase of 2.11 kilograms, or 4.62 pounds), whereas the bovine colostrum group experienced a significant increase in bone-free lean body mass (LBM, mean increase of 1.49 kilograms, or 3.28 pounds). However, as pointed out by Dr. Antonio and coworkers, one must exercise caution with this interpretation because some investigators have found the coefficient of variation for lean body mass estimates via DEXA to be as high as 3.1 percent. Certainly, this is as large as the difference in LBM reported for the colostrumsupplemented group. Further, there were no changes in any of the other parameters measured.

Colostrum and Exercise Performance The purpose of the recent study by Dr. Coombes and colleagues was to determine the dose effects of colostrum supplementation on cycling performance.6 Forty-two competitive cyclists were randomly divided into three groups and were required to consume either 20 grams of colostrum + 40 grams of whey protein; 60 grams of colostrum; or 60 grams of whey protein (placebo). Two measures were used to assess performance before and after an eightweek supplementation period. The first measure required subjects to complete two maximal oxygen uptake (VO2 max) tests separated by 20 minutes with the amount of work completed in the second test used to evaluate performance. The second performance measure was the time to complete a work-based time trial following a two-hour cycle at 65 percent maximal oxygen uptake. Subjects were required to maintain their regular training and keep a food and training diary over the study period. After supplementation, the performance enhancement in measure one was not statistically significantly different in the colostrum groups compared to the placebo group. In performance measure, two subjects in the 20-gram and 60-gram groups completed the time trial significantly faster post-supplement compared to pre-supplement. The authors concluded that colostrum supplementation at 20 or 60 grams per day provided a small but significant improvement in time trial performance in cyclists after a two-hour ride at 65 percent maximal oxygen uptake. Further, the authors postulated that bovine colostrum supplementation improves small intestine function and nutrient absorption leading to enhanced nutrient availability to recovering muscle cells. More recently, Dr. Jonathan Buckley and colleagues examined the effects of colostrum supplementation on peak vertical jump power, peak cycle power, alactic anaerobic work capacity and resistance exercise one-repetition maximum (1-RM).10 Using a randomized, double-blind, placebo-controlled parallel design, 51 males completed eight weeks of resistance and plyometric training while consuming 60 grams per day of colostrum or whey protein. Peak vertical jump power and peak cycle power were not significantly different between groups by week four. By week eight, however, peak vertical jump power and peak cycle power were significantly higher in colostrum condition. The authors concluded that colostrum supplementation during training significantly increased peak anaerobic power, but had no effect on alactic work capacity or 1-RM. Since colostrum supplementation had no significant effect on 1-RMs in this study, or in a previous study by Dr. Antonio and co-workers,5 and 1-RM provides a measure of muscular strength, it’s unlikely that colostrum exerted its effects by increasing muscle contractile protein content or by recruiting additional motor units. According to Dr. Buckley and colleagues, it’s more likely that the increased phosphogenolytic rate may have resulted from an increase in the relative proportion of fast myosin heavy chain. Colostrum and IGF-I Growth hormone is a protein anabolic hormone that produces positive nitrogen and phosphorous balance, and a fall in the blood urea nitrogen and amino acid levels. The effects of growth hormone on growth, cartilage and protein metabolism depend on an interaction between growth and

somatomedins, which are polypeptide growth factors secreted by the liver and other tissues. The principal (and in humans, probably the only) circulating somatomedins are insulin like growth factor 1 (IGF-1) and insulin-like growth factor 2 (IGF-2). IGF-2 is thought to be a less effective anabolic agent than IGF1. The majority of studies support the fact that IGF-1 has significant anabolic and anticatabolic effects, especially when acting with insulin and GH where there is an adequate amount of certain amino acids. Thus, increasing endogenous levels of IGF-1 could be useful for maximizing the effects of exercise on muscle mass and strength. The purpose of a study by Dr. Antti Mero and colleagues was to examine the effects of bovine colostrum supplementation on serum IGF-1 concentrations during strength and speed training period.12 Bovine colostrum supplement contained 67.6 micrograms per liter of IGF-1. Nine male sprinters and jumpers underwent three randomized experimental training treatments of eight days separated by 13 days. The only difference in the treatments was the drink of 125 milliliters consumed per day. Post-exercise increases were noticed for serum IGF-1 in the 25-milliliter bovine colostrum treatment (125 ml contained 25 ml colostrum) and especially in the 125-milliliter bovine colostrum treatment (125 ml contained 125 ml colostrum) compared with the placebo (whey protein) treatment. However, investigators used a radioimmunoassay that measures both the IGF-1 and its associated binding proteins. A more appropriate and accepted procedure is to remove the binding protein before measuring IGF-1. Furthermore, the negligible change in IGF-1 level could be due to the training effect. As might be expected and as found in normal physiology, the observed exercise-associated rise in growth hormone would be mirrored by a rise in circulating IGF-1. Finally, it should be noted that the initial mean level of IGF-1 was somewhat greater in the placebo group. This means the possibility that reasons other than colostrum supplementation may have contributed to the differences in the IGF-1 concentration between the groups. In follow-up study, Dr. Mero and coworkers examined the effects of bovine colostrum supplementation on blood and saliva variables and the absorption of orally administered human recombinant IGF (rhIGF-1) labeled with 123iodine. Authors concluded that long-term supplementation of bovine colostrum increases serum IGF-1 concentration in athletes during training. However, absorption data gives no support to the absorption of intact IGF-1 from bovine colostrum. We recently examined effects of colostrum supplementation on serum IGF-1, growth hormone (GH) and testosterone. In order to avoid effects of exercise, serum concentration of IGF-1, GH and testosterone were measured initially (day 0) and before the first exercise test (day 11) in all subjects. Serum IGF-1, GH and testosterone concentrations were within the reference ranges and no statistically significant changes were seen in response to 11 days administration of colostrum or placebo (whey protein). Further, the counts of red blood cells, leukocytes, thrombocytes, hemoglobin, hematocrit, cortisol and interleukin-6 were within reference limits at the beginning of the experimental period and did not show significant changes during colostrum or placebo supplementation. Colostrum and Upper Respiratory Tract Infection

Colostrum is a rich source of immunoglobulins. Circulating immunoglobulins protect their host by binding to and neutralizing some protein toxins; by blocking the attachment of some viruses to cells; by opsonizing bacteria (making it more susceptible to cell action that absorbs harmful microorganisms); and by activating proteins in blood plasma that aid in destruction of harmful bacteria. Immunoglobulin A is the major immunoglobulin found in mucosal secretions, which constitute the first barrier to the entry of pathogens into the body. Consequently, the level of secretory immunoglobulin A contained in mucosal fluids has been shown to correlate highly with resistance to certain infections caused by viruses, such as upper respiratory tract infection. Recently, Dr. Mero and colleagues reported that colostrum increases salivary immunoglobulin A concentrations after two weeks of supplementation.12 Therefore, it is possible that an increase in salivary immunoglobulin A may protect against the development of upper respiratory tract infection. Drs. Grant Brinkworth and Jonathan Buckley examined whether colostrum affected the incidence or duration of self-reported symptoms of upper respiratory tract infection in adult males. One hundred and seventy-four healthy, physically active adult males comprised the sample for this study. During the supplementation period, 93 subjects consumed colostrum, while 81 consumed whey protein. During the pre-experimental period, there was no significant difference in proportion of subjects taking the different supplements who reported symptoms of upper respiratory tract infection. During the seven-week experimental period, a significantly lesser proportion of subjects taking colostrum reported symptoms of upper respiratory tract infection compared with those taking whey protein. Thirty-two percent of subjects taking colostrum reporting at least one episode of upper respiratory tract infection, compared with 48 percent who were taking whey protein. This study provides preliminary evidence that colostrum may enhance resistance to the development of symptoms of upper respiratory tract infection in young adult males. However, colostrum appeared to have no effect on the duration of symptoms once they developed, indicating that it’s unlikely to be useful as a therapeutic treatment for upper respiratory tract infection once infection has occurred. References 1. Manninen AH (2002) Protein metabolism in exercising humans with special reference to protein supplementation. Masters thesis. University of Kuopio Medical School. 2. Lemon PWR (1998) Effects of exercise on dietary protein requirements. Int J Sports Nutr, 8:426-447. 3. Williams, MH (2001) Nutrition for Health, Fitness and Sport. New York: WCB/McGrawHill. 4. Manninen AH, Leppaluoto J (2002) Protein Efficiency Ratios (PER) of bovine colostrum, calcium caseinate, and standard diet. Department of Physiology, University of Oulu Medical School. Oulu, Finland. 5. Antonio J et al. (2001) The effects of bovine colostrum supplementation on body composition and exercise performace in active men and women. Nutr, 17:243-247. 6. Coombes JS et al. (2002) Dose effects of bovine colostrum on physical work capacity in cyclists. Med Sci Sports Exerc, 34:1184-1188. 7. Buckley JD et al. (2002) Bovine colostrum supplementation during endurance running training improves recovery, but not performance. J Sci Med Sport, 5:65-79. 8. Hofman Z et al. (2002) The effect of bovine colostrum supplementation on exercise performance in elite field hockey players. Int J Sports Nutr Exerc Metab, 12:461-469.

9. Brinkworth GD et al. (2002) Oral bovine colostrum supplementation enhances buffer capacity but not rowing performance in elite female rowers. Int J Sports Nutr Exerc Metab, 12:349-363. 10. Buckley, JD et al. (2003) Effect of bovine colostrum on anaerobic exercise performance and plasma insulin-like growth factor I. J Sports Sci, 21:577-588. 11. Brinkworth GD, Buckley JD (2003) Concentrated bovine colostrum protein supplementation reduced the incidence of self-reported symptoms of upper respiratory tract infection in adult males. Eur J Nutr, 42:228-232. 12. Mero A et al. (2002) IGF-1, IgA and IgG responses to bovine colostrum supplementation during training. J Appl Physiol, 93:732-739.

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