Outline

Height, body composition and IGF levels have all been shown to be associated with cancer risk, in particular breast and prostate cancer. The extent to which nutrient availability in the prenatal period affects these phenotypes and subsequent cancer risk is largely unknown. Genetic variation can influence dietary intake and metabolism of nutrients, thus affecting exposure to specific dietary components, such variation will be exploited in this project. The advantage of this method is that associations between genetic polymorphisms and height, body composition and IGF levels are not subject to the problems of measurement error, recall bias and confounding.[i] The use of genes as surrogates for measuring exposures in epidemiology has been termed Mendelian Randomisation, and is gaining recognition as an important research tool, marked by the establishment of an MRC Centre for Causal Analyses in Translational Epidemiology at the University of Bristol.

Suitable candidate genes include those which are; a) associated with nutrient intake, such as the lactase gene, polymorphisms of which determine lactose intolerance and therefore milk intake[ii] b) involved in nutrient metabolism, for example the MTHFR gene which is involved in the metabolism of folate,[iii] c) important in the transport and intern