Elderberry Supplementation Reduces Cold Duration and Symptoms in Air-Travellers: A Randomized, Double-Blind Placebo-Controlled Clinical Trial

Abstract

Intercontinental air travel can be stressful, especially for respiratory health. Elderberries have been used traditionally, and in some observational and clinical studies, as supportive agents against the common cold and influenza. This randomized, double-blind placebo-controlled clinical trial of 312 economy class passengers travelling from Australia to an overseas destination aimed to investigate if a standardised membrane filtered elderberry (Sambucus nigra L.) extract has beneficial effects on physical, especially respiratory, and mental health. Cold episodes, cold duration and symptoms were noted in a daily diary and assessed using the Jackson score. Participants also completed three surveys containing questions regarding upper respiratory symptoms (WURSS-21) and quality of life (SF-12) at baseline, just before travel and at 4-days after travel. Most cold episodes occurred in the placebo group (17 vs. 12), however the difference was not significant (p = 0.4). Placebo group participants had a significantly longer duration of cold episode days (117 vs. 57, p = 0.02) and the average symptom score over these days was also significantly higher (583 vs. 247, p = 0.05). These data suggest a significant reduction of cold duration and severity in air travelers. More research is warranted to confirm this effect and to evaluate elderberry's physical and mental health benefits.

Keywords: clinical trial; cold symptoms; complementary medicines; elderberry; nutritional supplements; physical health; sambucus; travel.

Figure 1

Study design.

Figure 2

Flowchart of trial participants (ITT—Intention to treat analysis, PP—Per protocol analysis).

Figure 3

Cold episode days (A) and cold symptom score (B) of participants with a well-defined cold established from the Jackson Score.

Figure 4

Effect of elderberry supplementation on the prevalence of Respiratory Disease Symptom positive (RDS+) participants.

Figure 5

Y axis shows average Quality of Life (QoL) scores for physical health Physical Health Composite Scores (PCS) for each treatment group at the three time points surveyed (X-axis) for all participants.

Figure 6

Y axis shows average QoL scores for mental health Mental Health Composite Scores (MCS) for each treatment group at the three time points surveyed (X-axis) for all participants.