Nutraceuticals have shown benefit in the prevention of the common cold but previous investigations have been inconsistent. This study was designed to determine the preventive effect of a dietary supplement from fruits and vegetables on common cold symptoms. In a double-blind, placebo-controlled trial, 529 healthcare professionals (mean age 39.9 years) from a university hospital in Germany were randomized to receive four capsules of a dietary supplement (Juice Plus+®) or a matching placebo daily for eight months. The number of days with moderate or severe common cold symptoms within six months was assessed by diary self-reports. The mean number of days with moderate or severe common cold symptoms was 7.6 (95 % CI 6.5 – 8.8) in the Juice Plus+® group and 9.5 (95% CI 8.4 – 10.6) in the placebo group (p = 0.023). The mean number of total days with any common cold symptoms was similar between the Juice Plus+® and placebo groups. The authors concluded that the intake of a dietary supplement from fruits and vegetables was associated with a 20% reduction of moderate or severe common cold symptom days in healthcare professionals particularly exposed to patient contact. Br J Nutr. 2011 Jan;105(1):118-22. PMID: 20727236
