2.3. Gastroenterology
2.3.1. Esophagus
Esophageal cancer has a poor prognosis with low rates of disease survival [40]. Oxidative damage from smoking, alcohol, and gastroesophageal reflux disease (GERD) increases the risk of esophageal cancer, which some suggest may be mitigated through the use of antioxidant agents [40, 41]. In a study conducted by Stoner and colleagues, the authors evaluated the hypothesis that a blueberry diet induces anticarcinogenic, anti-inflammatory, and antioxidant effects in N-nitroso-methyl-benzylamine (NMBA) treated rats [41]. NMBA is an established carcinogen that induces tumorigenesis in the rat esophagus in a multistep fashion that is analogous to the esophageal carcinogenesis in humans. The authors found that rats treated with NMBA for five weeks, followed by a blueberry diet for a total of 35 weeks, had increased antioxidant activity, reduced tumorigenesis, and decreased expression of interleukin- (IL-) 5 and growth-related oncogene (GRO/KC), two markers of inflammation.
Currently, the relationships between anticarcinogenesis, anti-inflammation, and increased antioxidant activity in the pathogenesis of esophageal malignancy have not been fully elucidated.
It has been postulated that high antioxidant capacity of blueberries facilitates mechanisms of cell death in malignant cells; however, further studies are needed to assess whether the anticancer effects of blueberry treatment in esophageal cancer are related to the antioxidant effects of pterostilbene, which also induces anticancer effects in several digestive malignancies.