Effect of Helicobacter Pylori on the Availability of Vitamin E and C
It has been postulated that dietary antioxidants may reduce cancer risk by modulating red-ox
status, by preventing biological oxidation, and by inhibiting the formation of carcinogen.
However, supplementation studies and prospective studies have yielded contradictory results.
In the case of gastric cancer, H.pylori infection, which is known to be associated with a
higher risk of the disease, results in an increased production of ROS & RNS. As a result
serum levels of these free radicals increase, exerting a higher demand for dietary
antioxidants to neutralize them.
The fact that the relation between serum levels of antioxidants and gastric cancer is more
consistent than that of dietary intake levels and the disease suggests the possibility of
the presence of an intrinsic factor that is altering the true relation between dietary
antioxidants and the cancer. This intrinsic factor, this study argues, is the infection with
H.pylori infection, by increasing the production of reactive oxygen species, increases the
utilization of dietary antioxidants that serve in quenching the free radicals, thus
decreasing their serum levels and confounding their protective effect against gastric
cancer. The purpose of this pilot study is to investigate the possibility that H.pylori
infection alters the bioavailability of the dietary antioxidants: vitamin C, and vitamin E.
This project will be done in preparation for an etiologic study of dietary antioxidants and
Allocation: Non-Randomized, Endpoint Classification: Pharmacokinetics/Dynamics Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Prevention
plasma vitamin C levels
Farah Naja, MSc.
Canada: Cancer Care Ontario
Canada: University of Toronto