Kiwifruit and Cancer: An Overview of Biological Evidence.

Kiwifruit consumption is associated with many favorable health benefits. This article is hence aimed to provide an overview on potential effects of kiwifruit on cancer development or progression. An electronic search was performed in Medline and Web of Science, for identifying original studies exploring the relationship between kiwifruit and cancer development or progression, both in vivo and in vitro. The following keywords were used: "Kiwifruit" OR "Kiwi" OR "Actinidia deliciosa" OR "Actinidia chinensis," in combination with "cancer" OR "malignancy" OR "neoplasm." Overall, 58 items could be retrieved, fifty of which were excluded since they did not fulfilled all our search criteria. Eight studies (five in vitro studies, two human intervention trials, and one both in vivo and in human study) were finally included in this critical literature review. Taken together, the results of these published studies suggest that kiwifruit supplementation may be associated with direct and indirect anticancer effects, the former likely due to ascorbic acid-mediated reduction of DNA oxidative injury and cytotoxic effect on cancer cell lines, the latter more likely attributable to enhanced daily bowel movements and increased intestinal fecal content of lactic acid bacteria, which would finally contribute to lower the risk of malignancies, especially colorectal cancer.