The clinical efficacy of a bovine lactoferrin/whey protein Ig-rich fraction (Lf/IgF) for the common cold: A double blind randomized study

SummaryObjectiveThe aim of the study was to determine if a bovine lactoferrin/whey protein Ig-rich fraction (Lf/IgF) combination was effective in reducing the number of colds and in turn improving symptom recovery in a cohort of males and females that reported frequently contracting a cold.DesignA double blind randomized placebo-controlled clinical trial.SettingOne-hundred and twenty-six participants matched by age, BMI, dietary and physical parameters with self-reported frequent upper respiratory tract symptoms and infections were randomly assigned to receive 600 mg of Lf/IgF or a placebo daily for 90 days.Main outcome measures and resultsA total of 90 participants (47 receiving the active and 43 placebo) completed the 90 day trial and 15 completed 45 days participation (6 in the active and 9 in the placebo group). The total number of colds recorded over the study period was 48 for the treatment group versus 112 for the placebo group (p < 0.001). The significant trend was retained when the data was corrected for medications returned (p < 0.001) and for guessing treatment allocations (p < 0.001). Non-parametric analysis demonstrated that the total number of cold-associated symptoms reported by participants that received Lf/IgF was significantly less than those in the placebo group (p < 0.05). Also, total days sick with a cold and cold severity were reduced over the clinical trial period for Lf/IgF over placebo, but the trend was not significant.ConclusionsThese findings demonstrate that the Lf/IgF combination significantly decreased the incidence of colds and the cumulative number of cold-related symptoms over placebo. This therapeutic combination may be indicated for the prevention of colds and its most common symptoms in the general population when administered as a preventative supplement.