Many people are experiencing the symptoms of the common cold this winter, sniffles, runny nose, sore throat, stuffy ears. I have previously written about diet and dietary supplements for the prevention of the common cold however, investigations with supplements are, as yet, inconclusive and results inconsistent. Having a healthy diet which provides the body with abundant nutrients may be helpful in the prevention of the cold since a good diet helps keep the immune system functioning effectively.
The common cold is the most frequent acute illness in industrialised societies (1). It is a viral infectious disease of the upper respiratory tract, caused by a variety of viruses. The leading symptoms include sneezing, runny or congested nose, sore throat, headache and coughing, typically lasting for about 5–10 d. On average, adults experience two to four colds per year. Frequency of common cold infections increases in the UK in the autumn and winter (1).
Since there is no causal treatment for the common cold, therapy focuses on symptom relief. In addition, preventive strategies for the common cold include lifestyle measures such as avoiding infected people and regular hand washing during the winter. As mentioned above dietary supplements including herbs and vitamins have been suggested in the prevention of the common cold, but previous investigations have proven inconclusive.
A recently published study(1) was designed to determine the preventative effect of a dietary supplement made from a concentration of fruits and vegetables on common cold symptoms. The study was well designed, a randomised, double-blind, placebo-controlled trial. It involved over 500 healthcare professionals, mainly nursing staff aged 18–65 years, from a university hospital in Berlin, Germany. The individuals involved in the trial received the supplement or a matching placebo daily for 8 months. The number of days with moderate or severe common cold symptoms within 6 months was assessed by diary self-reports.
Results (1) found that the average number of days with moderate or severe common cold symptoms was reduced in the supplement group compared to the placebo group, intake of the dietary supplement was associated with a 20 % reduction of moderate or severe common cold symptom days. This is significant since the individuals involved in the study were healthcare professionals who were particularly exposed colds through patient contact. It is important to note, however that the average number of total days with any common cold symptoms was similar in both groups.
The results are interesting since the supplement helped to reduce the severity of the cold symptoms, even though the total number of days with symptoms was not reduced. Reducing the severity of symptoms is important since it may mean that individuals don’t take time off work and can carry on with their days as normal. Although colds are not really serious conditions, they are a leading cause of absence from work and doctor visits (1). In the current study the group taking the dietary supplement had fewer days with intake of common cold medication and a trend towards fewer days absent from work due to the common cold.
The authors of the study write “ To our knowledge, it is the first randomised investigation focusing on the benefits of juice powder concentrate in subjects particularly exposed to patient contact. The confirmation of the present findings in other populations could contribute to the growing scientific basis of assessing the clinical importance of dietary supplements from fruits and vegetables. In conclusion, intake of Juice Plus þ w was associated with fewer number of days with at least moderate common cold symptoms. Whether long-term intake of Juice Plus þ w could further reduce severity or even the frequency of common cold symptoms and the possible underlying mechanisms should be assessed in future studies”
Many supplements made from concentrated fruit and vegetables are now available. Such supplements may be considered as a short term measure especially if your diet is consistently falling short of fruits and vegetables. Supplements, however, can never be seen as an alternative to a healthy diet and it is always best to check with your medical doctor prior to starting a new supplement regimen. Eating a diet rich in a variety of vegetables, fruits and wholegrains will help to provide vitamins, minerals and flavonoids that may help to keep the immune system functioning optimally.
(1) Stephanie Roll S et al. 2011. Reduction of common cold symptoms by encapsulated juice powder concentrate of fruits and vegetables: a randomised, double-blind, placebo-controlled trial. British Journal of Nutrition (2011), 105: 118-122
Written by Ani Kowal