How does nutrition contribute to cancer cells creation?
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). The results found that the men consuming 420g of red meat had significantly higher levels of NOC (P=0.001) than those on a 60g low meat diet, and the men on the high red meat diet had increased fecal apparent total nitroso compounds (ATNC) than the vegetarian or low meat diet. The ATNC between the vegetarian and low meat diet was not significant (P=0.2). In protocol two the supplement of 7.8mg of haem iron had significantly greater faecal NOC levels (P=0.006) in comparison to the 60-gram low meat diet, however, the 35mg ferrous iron tablet had no effect. These results suggest the internal N-nitrosation increases from the consumption of haem – but not inorganic protein or iron. This could be accountable for an association, of an increased risk of colorectal cancer via red meat consumption. However, as this study was only performed on a small number of subjects, the statistical power of the results is decreased. A small sample size increases the chance of type 2 errors which may give skewed results.