Investigation of the natural supplement IQP-AS-119 for the prevention of upper respiratory tract infections in marathon race participants: A randomized, double-blind, placebo-controlled pilot study.

Intense and prolonged exercise leads to immune suppression, causing upper respiratory tract infections (URTI). A proprietary standardized dietary supplement, IQP-AS-119 has been previously developed to aid immune responses under such conditions. The current randomized, double-blind, placebo-controlled pilot study aimed to investigate the effects of IQP-AS-119 on marathon runners. A total of 80 participants were randomized equally into groups receiving either placebo (P group) or IQP-AS-119 (V group) treatment, starting 3 weeks before and for 14 days after the marathon. Benefit assessment was performed using different questionnaires. Post-marathon, the V and P groups reported 1±2.38 and 2.11±3.25 days with upper respiratory tract symptoms (URTS), respectively (P=0.038). During the 14 days post-marathon, 20.0% of the participants in the V group compared with 44.4% in the P group reported URTS (P=0.042). The V group reported significantly milder URTS compared with the P group on Days 9, 12, 13 and 14 post-marathon (P<0.05). The total Perceived Stress Questionnaire-20 score on days 2-14 were significantly lower for the V group compared with the P group (P=0.035). In the Short Form 12 Health Survey, the V group exhibited significant improvement in mental composite score on days -5 to 14 compared with the P group (P=0.038). In the overall treatment effect assessment, there were no statistically significant differences between the groups. The IQP-AS-119 was rated 'very good' or 'good' by investigators and participants, respectively, for 71 and 65% of the participants. The tolerability of IQP-AS-119 was rated as 'very good' or 'good' by both investigators and 95% of participants. No clinically relevant differences were observed between groups regarding adverse events or other safety parameters. Therefore, IQP-AS-119 was demonstrated to reduce the incidence and severity of URTI in marathon runners. Given its good tolerability profile, IQP-AS-119 may be a good nutritional supplement for the reduction of URTS in susceptible individuals.