Consumption of a diet high in plant-based foods is associated with a decreased risk of epithelial cell
cancers at several sites. Cytoprotectants in fruits and vegetables include
vitamins, minerals and numerous
micronutrients. While there is little evidence uniquely linking berry consumption with lower
cancer risk, berries contain high levels of compounds believed to reduce malignant transformation, including the
polyphenol flavonoids and
anthocyanins. There is strong and convincing evidence that berry extracts and berry
phytochemicals modulate
biomarkers of DNA damage and indicators of malignant transformation in vitro and in vivo. Data from numerous cell culture and animal models indicate that berry components such as the
anthocyanins are potent
anticarcinogenic agents and are protective against
genomic instability at several sites in the carcinogenic pathway. Anticarcinogenic mechanisms include modulation of
carcinogen activation and detoxification, decreased
DNA binding of the
carcinogen, inhibition of oxidative DNA damage, alteration in cell signalling and malignant transformation and inhibition of cell invasiveness and
metastasis. Exactly which berry constituents are cytoprotective remains uncertain and in the majority of in vitro and in vivo studies the concentration of extract or
phytochemical employed is non-nutritional. Evidence for an
anticarcinogenic effect in human studies is weak.