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

Objective: The 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.

Design: A double blind randomized placebo-controlled clinical trial.

Setting: One-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 Results: A 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.

Conclusions: These 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.