A micronutrient-dense concentrate of a range of fruit and vegetables including cherry, apple, broccoli, cranberry, orange, pineapple, spinach, and tomato was found to reduce the symptoms for moderate and severe common cold, according to findings published in the British Journal of Nutrition.
“Given the widespread utilisation of concentrated dietary products, the present study has potentially important public health relevance,” state researchers from Berlin’s Charité University Medical Centre.
“To our knowledge, it is the first randomised investigation focusing on the benefits of juice powder concentrate in subjects particularly exposed to patient contact,” they added.
Very common cold
The common cold is a viral infection primarily caused by rhinoviruses. It is the most common infectious disease in humans, and responsible for about 500 million illnesses in the US every year. According to a study published in the Archives of Internal Medicine, the common cold and related diseases costs the US about $40 billion every year (2003, Vol. 163, pp. 487-494.).
While various studies have looked at the potential of dietary supplements to reduce the incidence or severity of the common cold, but such research has yielded “inconsistent” results, claim the Berlin-based scientists.
The new study used the commercial products Juice Plus+ by Tennessee-based NSA LLC, and the company also funded the study. The fruit and vegetable juice powder concentrate contained acerola cherry, apple, beet, broccoli, cabbage, carrot, cranberry, kale, orange, peach, papaya, parsley, pineapple, spinach, and tomato, while the added berry powder included bilberry, blackberry, black currant, blueberry, cranberry, Concord grape, elderberry, raspberry and red currant.
Two-hundred and sixty three people were assigned to receive daily supplements of the fruit and vegetable concentrate, while 266 people received a placebo for eight months. Participants of the randomised, double-blind, placebo-controlled trial had an average age of 39.9 and 80 per cent were women.
Results showed no significant differences between the groups regarding the total number of days with any common cold symptoms. However, people receiving the fruit and vegetable concentrate had an average of 7.6 days with moderate or severe common cold symptoms, compared with 9.5 days in the placebo group.
“Intake of Juice Plus+ was associated with a fewer number of days with at least moderate common cold symptoms,” wrote the researchers.
Commenting on the potential mechanism, the Berlin-based scientists point to the high antioxidant content of the supplement, including vitamins C and E, as well as nutrients such as beta-carotene and folate that have been linked to improved immune function via increased numbers of T cells (white blood cells with a key role in immune health).
“Whether long-term intake of Juice Plus+ could further reduce severity or even the frequency of common cold symptoms and the possible underlying mechanisms should be assessed in future studies,” they concluded.
Source: British Journal of Nutrition
Published online ahead of print, First View Articles, doi:10.1017/S000711451000317X
“Reduction of common cold symptoms by encapsulated juice powder concentrate of fruits and vegetables: a randomised, double-blind, placebo-controlled trial”
Authors: S. Roll, M. Nocon, S.N. Willich