Cranberry Supports Immunity and Minimizes Cold and Flu Symptoms
A study published in December 2013 states that cranberry supplementation enhances immunity and resulted in fewer symptoms of the cold and flu. Cranberry contains organic acids and phytochemicals including proanthocyanidins and anthocyanins with significant antioxidant activity.
In this randomized, double-blind, placebo- controlled parallel study, researchers assigned 45 subjects to receive a low calorie cranberry beverage (450 ml) made with a juice-derived, powdered cranberry fraction or a placebo beverage daily for 10 weeks.The investigators assessed peripheral blood mononuclear cells in culture, which are cells important in immune function. The subjects reported cold and flu symptoms.
The investigators determined that the proliferation index of gamma-delta T-cells (immune cells that serve as the first line of defense against pathogens) in culture was almost five times higher after 10 weeks of cranberry beverage consumption. Additionally, the researchers showed that the incidence of illness was not reduced in the cranberry group. However, significantly fewer symptoms of illness were reported.
The investigators stated, "Consumption of the cranberry beverage modified the ex vivo proliferation of gamma-delta T-cells. As these cells are located in the epithelium and serve as a first line of defense, improving their function may be related to reducing the number of symptoms associated with a cold and flu."
Nantz MP, et al. Nutr J. 2013;12:161.