How does the iron influence the creation of cancer cells?

Studies suggest that iron promotes the formulation of reactive oxygen species or ROS from peroxidases through the Fenton reaction in the colon. It is this reaction and the production of hydroxyl radicals which is thought to contribute to the development of pro-mutagenic lesions and cellular toxicity. A study published in 2002 supports the previous statement, with results that identify an iron-overload induces oxidative damage to DNA causing breaks in the DNA strands and oxidized bases in the colon carcinoma cell line HT29 clone 19A, when ferric-nitrilotriacetate (a powerful hepatic tumor promoter) or hemoglobin, incubates the tumor cells. Hemoglobin was used as physiological iron, and when compared to FE-NTA it was discovered to be just as effective at causing DNA damage. These results show that iron is a potential colon cancer risk factor due to its capability of catalyzing reactive oxygen species formation.

Expanding on this study, another controlled study investigated the theory of haem iron promoting the formation of internal N-nitroso compounds in the large intestine after consumption of red meat, most of which have been found to be pro-carcinogenic. The study involved 21 healthy males who were provided food and drink and had fecal samples collected daily, weighed and x-rayed. In protocol 1, 12 men were fed either a high red meat diet (420g), low red meat diet (60g) or vegetarian diet all consisting of an equal amount of protein. In protocol 2, 9 men were fed over a 3-week period a supplement of 7.8-mg haem iron, a sliver platter and a blood sausage (equivalent to the iron content of 420g red meat – 17.7mg/day), 60-gram red meat diet (containing 9.9 mg/day iron) and a supplement tablet containing 300-mg ferrous gluconate (35 mg of ferrous iron).