Biomathematics & Statistics Scotland
N-nitroso compounds (NOCs) can be formed by chemical reactions in the gut, and are potentially carcinogenic. To identify dietary components that contribute to the formation of, or provide protection against, NOCs we analysed data from three controlled dietary intervention trials. During the trials, obese men were fed different weight loss diets, with varying intakes of red meat, protein, carbohydrate, fibre, vitamin C and nitrate.
The amounts consumed were recorded and stool samples
were collected and analysed for NOC concentrations. We
investigated which dietary intake variables were responsible for changes in faecal NOC by regressing the NOC
data on one or more of the intake variables, accounting for differences between individuals, study groups and
study duration using random effects models with various residual error structures. Our models identified that,
in addition to red meat intake being an important contributor to the formation of NOCs, reduced total energy
intake from low carbohydrate weight loss diets and increased nitrate intake are also associated with an increase in
NOCs. Conversely, the intakes of dietary vitamin C and dietary fibre were found to play a potentially protective
role. Our findings highlight the importance of balancing potentially problematic foods (red meat, nitrate) with
protective ones such as vitamin C and dietary fibre.
Further details from: Grietje Holtrop
Article date 2013
