EFSA’s Panel on Dietetic Products, Nutrition and Allergies found that the 17 scientific references submitted by Leiber for its branded Yestimun ingredient did not demonstrate how the ingredient could help reduce the common cold.
Submitted under article 13.5, the claimed effect was for “reducing the risk for common cold infections by decreasing the susceptibility for common cold infections during the cold season by strengthening the body’s natural defences and improving the body’s immune defence against common cold viral infections during the cold season”.
Leiber had submitted 10 human studies, five animal studies and two in vitro studies in support of Yestimun, a beta-glucan ingredient derived from brewer’s yeast cell wall.
However, EFSA dismissed four of the human studies as they had been conducted using intravenously injected beta-glucans, which was considered to be an “inappropriate route of exposure”.
An additional four human studies that used oral administration were also dismissed as the changes of immune parameters did not represent “an improvement on the initiation of appropriate innate and adaptive immune responses.”
Another study was dismissed because it recruited a very small number of subjects, there was a high drop out rate, a multiplicity of ‘primary outcomes’, and a lack of adjustment for multiple testing. Another study was not found to have statistically significant results.
EFSA’s NDA panel also said that that the “evidence provided in animal and in vitro studies does not predict an effect of Yestimun on the initiation of appropriate innate and adaptive immune responses in humans.”
The panel concluded that a cause and effect relationship was not established between the consumption of Yestimun and the initiation of appropriate innate and adaptive immune responses.