J Nutr. 2012 Sep;142(9):1652-8.
Diet composition is associated with endogenous formation of N-nitroso compounds in obese men.
Holtrop G, Johnstone AM, Fyfe C, Gratz SW.
Source
Biomathematics and Statistics Scotland, Bucksburn, Aberdeen, UK.
Abstract
Endogenous formation of carcinogenic N-nitroso compounds (NOC) occurs in the
human gut. Red meat is considered the most important dietary component linked to
NOC formation, although nitrate and vitamin C (VitC) also contribute. We
previously showed that high-protein weight-loss diets increased fecal NOC and
this was enhanced by simultaneous carbohydrate restriction. Although previous
studies have focused on the effect of either 1 or 2 dietary components on
endogenous NOC formation, no study to date has investigated the combined
contribution of various dietary components. The current study therefore assessed
the joint impact of several known dietary contributors to the endogenous
formation of NOC in obese men. It also aimed to identify further novel
contributors and investigate their role in explaining shifts in endogenous
formation of NOC. Three dietary trials were conducted in obese men consuming
body weight maintenance or weight-loss diets, with NOC measured in fecal samples.
Consumption of meat-based weight-loss diets increased (P < 0.001) fecal NOC. Red
meat intake was positively correlated with the fecal log NOC concentration (r =
0.60; P < 0.001). Dietary carbohydrate and sugar were negatively correlated with
the fecal log NOC concentration (r = -0.66 for both; P < 0.001). Multiple
regression analysis identified several dietary components that drive endogenous
NOC formation, namely, red meat, nitrate, VitC, total energy, and nonstarch
polysaccharides. We present a regression model that predicts endogenous NOC
formation in obese men based on their dietary intakes. This model could improve
the estimation of endogenous NOC formation, currently used in epidemiological
studies into diet and cancer.
PMID: 22833653 [PubMed - indexed for MEDLINE]