Reviewed: Tiralongo E, Wee SS, Lea RA. Elderberry supplementation reduces cold duration and symptoms in air-travellers: a randomized, double-blind placebo-controlled clinical trial [published online March 24, 2016]. Nutrients. doi: 10.3390/nu8040182.
Air travelers are often subject to stressors, such as fatigue, travel stress, and related compromised immune function. Close proximity to other travelers also may result in an elevated risk of contracting or spreading communicable diseases, such as the common cold. European elder (Sambucus nigra, Adoxaceae) berries have been shown in previous clinical studies to lessen the symptoms and duration of both colds and influenza infections.1,2 This randomized, double-blind, placebo-controlled trial focused on whether or not a European elderberry extract (BerryPharma; Iprona AG; Lana, Bolzano, Italy) helped prevent respiratory symptoms and had a positive impact on the physical and mental health of air travelers.
The trial was conducted between April 2013 and December 2014, and study subjects were recruited from the Gold Coast region of Australia. Included subjects were at least 18 years old and healthy. Criteria for exclusion were participation in another clinical trial at the time of the study or within 30 days of the study; presence of plant allergies, respiratory problems, or other diseases; vaccination against influenza within 10 days of the study; and use of medications such as antibiotics or antivirals. Women who were lactating, pregnant, or intending to become pregnant also were excluded.
Subjects were economy-class passengers, who traveled for at least seven hours overseas from Australia (with a layover of less than 12 hours) and spent at least four days at their final destination. Subjects (N = 312) began either the treatment or the placebo 10 days prior to their flight and continued for five days after arrival at the destination. This resulted in a total treatment duration of 15 or 16 days. Subjects completed questionnaires addressing cold symptoms and duration, quality of life, and stress levels at baseline, two days before travel, and four to five days after travel.
The BerryPharma extract was packaged into capsules by Plantafood Medical GmbH of Leiningen, Germany. Capsules contained 300 mg of extract standardized to 22% of polyphenols, 15% anthocyanins, and 150 mg of rice (Oryza sativa, Poaceae) flour. Placebo capsules were considered to be "matched." The manufacturer and exact description of placebo content(s) are not given. The dosage was two capsules daily from 10 days until two days prior to travel, and three capsules daily starting one day prior to travel and continuing for four to five days after arrival at the destination. Remaining capsules were counted to gauge compliance.
To assess the presence and severity of cold symptoms, subjects completed the Jackson Score questionnaire. Symptoms such as nasal obstruction, sore throat, and cough were assessed in this questionnaire, with scores from 0 (absence of symptoms) to 3 (severe symptoms). Daily use of cold medications, as well as whether subjects thought they had a cold, were recorded. Colds were defined as a total symptom score of > 14 over six days with the belief of the presence of a cold for three or more days. Also assessed were the number, duration, and symptoms of colds that required medication.
To assess the impact of colds on quality of life, the Wisconsin Upper Respiratory Symptom Survey (WURSS-21) was used. This survey uses a seven-point Likert scale, in which a lower score indicates better health. Symptom severity, functional impairment, and global severity and change over the prior 24 hours were gauged. Another assessment for quality of life was the Short Form Health Survey (SF-12). This questionnaire measured physical and mental health based on 12 questions; the score ranged from 0 (worst health) to 100 (optimum health). To gauge stress, the Perceived Stress Scale (PSS) was employed. The PSS addresses how subjects experience stress in their lives, with higher scores indicating greater stress. A score of > 14 was considered indicative of a large degree of stress.
In total, 325 subjects were randomly assigned to either the elderberry or placebo group. Of these, 13 subjects did not take the treatments due to loss of material in the mail, pneumonia, alteration in travel or decision, or family emergency. The intention-to-treat analysis included 312 subjects, with 158 in the elderberry group and 154 in the placebo group. Most subjects were women (66%), non-smokers, around 50 years old, and conducted holiday air travel of more than 16 hours between April 2013 and December 2014. Subjects’ PSS scores were > 14 at baseline. Around half the subjects had received an influenza vaccination at least 10 or more days prior to the start of the study. Demographics were not significantly different between groups at baseline.
During the study, 12 subjects in the elderberry group and 17 in the placebo group had a cold, according to the Jackson Score questionnaire (this difference between groups was not significant). Of these 29 subjects, symptoms were detectable in 11 subjects prior to travel, in three during travel, and in 15 upon arrival at their destination. The number of days that subjects in the elderberry group had a cold was less than in the placebo group, bordering on significance (57 days total versus 117 days, respectively; P = 0.05). The average cold symptom score over these days was significantly less in the elderberry group than the placebo group (247 versus 583, respectively; P = 0.02).
Half of the subjects with colds took medications to treat cold symptoms, but there was no significant difference between groups. The average WURSS-21 scores were not significantly different between the groups at any point; however, those in the elderberry group reported fewer cold symptoms prior to travel than those in the placebo group, approaching significance (P = 0.07). According to the SF-12 questionnaire, average physical health scores significantly decreased from baseline in the placebo group across the study (P = 0.005), while no change in scores was observed in the elderberry group. In total, 90% of subjects were 90% compliant with the protocol. Adverse side effects such as itchy throat, “cold-like” symptoms, and fatigue were reported in both groups (four subjects), while kidney pain was reported by one subject in the placebo group.
Based on the data shown here, the authors conclude that taking European elderberry extract may result in a shorter duration of a cold with less symptom severity. Previous studies have also found beneficial effects of elderberry extract on colds. The authors mention that many subjects used additional medications to treat their colds, and this may have confounded symptom reporting. In general, this study suggests that European elderberry extract can help alleviate colds associated with travel. Future studies will ideally include a broader population and other stressful environments, and elucidate potential mechanisms of action. The study was funded by Iprona AG, which also provided the European elderberry and placebo capsules and was partially involved in the design of the study.
-Amy C. Keller, PhD
References
- Vlachojannis JE, Cameron M, Chrubasik S. A systematic review of the sambuci fructus effect and efficacy profiles. Phytother Res. January 2010;24(1):1-8.
- Kong F. Pilot clinical study on a proprietary elderberry extract: efficacy in addressing influenza symptoms. Online Journal of Pharmacology and Pharmacokinetics. 2009;5:32-43.