Background: Anecdotal reports suggest that bovine colostrum may prevent upper respiratory tract infection (URTI). There is scant evidence to support such claims, although salivary IgA protects against URTI, and it was recently shown that bovine colostrum increases salivary IgA.
Aim of the study: The present invesigation examined whether concentrated bovine colostrum protein (CBC) affected the incidence or duration of self-reported symptoms of URTI in adult males.
Methods: We examined logbooks containing self-reported symptoms of illness from previous studies which examined physiological effects of CBC. In these double-blind, placebo controlled studies, subjects had been randomly allocated to consume 60g. day(-1) of CBC (n = 93) or whey protein (WP) (n = 81) for eight weeks. Symptoms were coded using established criteria to identify those related to URTI. Since the incubation period for an URTI is up to five days, symptoms reported during the first week of supplementation (PRE-EXP) were analysed separately to preclude those arising from infection prior to study commencement.
Results: During PRE-EXP, there was no difference in the proportion of subjects taking the different supplements who reported symptoms of URTI (CBC, 11%,WP, 5%; 95% Confidence Interval (95% CI) -14% to 2%; P = 0.16). During the subsequent seven weeks (i. e. the experimental period), a significantly lesser proportion of subjects taking CBC reported symptoms of URTI compared with those taking WP (CBC, 32%,WP, 48%, P = 0.03; 95 % CI -30 % to -2 %), but symptom duration did not differ (CBC, 6.8 +/- 4.2 days,WP, 6.0 +/- 4.4 days; P = 0.27).
Conclusion: This study provides preliminary evidence that CBC may enhance resistance to the development of symptoms of URTI.