(NaturalNews) A puree of the gold kiwifruit may help boost immune function and response to infection, according to a study conducted by researchers from the Horticulture and Food Research Institute of New Zealand and The Hopkirk Research Institute, and published in the journal Nutrition Research. The study was funded by Zespri Group, which sells gold kiwifruit.
"This report demonstrates that the Zespri Gold Kiwifruit puree enhances an adaptive immune response to an orally administered antigen in mice," the researchers wrote. "Such a finding suggests that this product has the potential to be a functional food ingredient, particularly because the process used to produce the Zespri Gold Kiwifruit puree facilitates retention of nutrients, vitamins, heat-sensitive phytochemicals, water-soluble polysaccharides, and dietary fiber present in the whole fruit."
The researchers exposed female mice the egg protein ovalbumin mixed with a low dose of cholera toxin, a mixture known to enhance immune responses to ovalbumin. The mice were also fed either a puree of gold kiwifruit, the juice of the fruit or a sugar solution. After 20 days, the immune responses of the mice were measured.
The mice in the puree group had significantly higher levels of both total immunoglobulins and of immunoglobulin G, indicating an elevated immune response, than the mice in the control group. There was no significant difference between the immune responses of mice in the juice and control groups.
The specific kiwifruit ingredients or combination of ingredients that led to the improved immune response is not yet known. The researchers hypothesized that the fruit's high carotenoid content may play a role, as might its high fiber content.
Prior research has found that certain prebiotic fibers improve immune response by stimulating the growth of certain colon flora, while the carotenoids beta-carotene and lutein are believed to stimulate the production of antibodies.
Other studies have found that kiwifruit may function as a laxative and reduce the blood clotting that elevates the risk of strokes and deep vein thrombosis.