Moyad MA, Robinson LE, Zawada ET Jr, et al. Effects of a modified yeast supplement on cold/flu symptoms. Urol Nurs. 2008;28(1): 50-55.
Although the common cold is not a major medical concern, the virulent variants of the virus are becoming more common. The identification of preventive therapies or complementary treatments may be beneficial in decreasing the symptoms and duration of influenza and colds. Notable recent entries in the alternative/complementary cold/flu sweepstakes have been andrographis, Echinacea, and ginseng.
Saccharomyces cerevisiae, better known as baker's or brewer's yeast, has a long history of providing some form of immune protection or health promotion. This 12-week, randomized, double-blind, placebo-controlled trial was conducted during the acute period of the year for cold and flu seasonal symptoms to examine the impact of a unique yeast-based dietary supplement on the incidence of cold and flu-like symptoms.
Subjects (n=130) from the rural Midwest, and who had recently received the seasonal influenza vaccine, were randomized to 1 of 2 groups. The experimental group (n=52) received daily doses of 500 mg modified yeast-based (S. cerevisiae) product intervention (EpiCor®, Embria Health Sciences, Ankeny, IA); the control group (n=64) received a placebo. Subjects were assessed at baseline and weeks 6 and 12. In addition, the subjects were required to record cold and flu-like symptoms at home in a diary.
Both groups demonstrated similar baseline parameters. While 130 subjects began the study, there was a total of 14 dropouts during the study, including 10 in the EpiCor group and 4 in the placebo group. The final analyses were performed on the 116 subjects who completed the study.
EpiCor significantly reduced the incidence (P=0.01) and duration (P=0.03) of the common cold or flu-like symptoms compared with placebo. In addition, compared with placebo, EpiCor significantly reduced several specific symptoms: incidence of hoarseness (P=0.008), incidence of nasal stuffiness (P=0.008), and duration of weakness (P=0.008).
The rate of adverse events was similar for the EpiCor and placebo groups, 30.8% and 39.1%, respectively. No serious adverse events were reported for subjects receiving EpiCor. Furthermore, no abnormalities were found with any of the laboratory parameters.
The authors claim that this study is the largest randomized placebo-controlled trial to date to demonstrate that a yeast-based product may improve immune surveillance and outcomes in an otherwise healthy population. In light of the promising outcomes demonstrated in this study, the authors have initiated an additional study of EpiCor, regardless of vaccine status of the subjects.