Mendelian randomization: how it can--and cannot--help confirm causal relations between nutrition and cancer.

ABSTRACT: Observational epidemiologic studies of nutrition and cancer have faced formidable methodologic obstacles, including dietary measurement error and confounding. We consider whether Mendelian randomization can help surmount these obstacles. The Mendelian randomization strategy, building on both the accuracy of genotyping and the random assortment of alleles at meiosis, involves searching for an association between a nutritional exposure-mimicking gene variant (a type of "instrumental variable") and cancer outcome. Necessary assumptions are that the gene is independent of cancer, given the exposure, and also independent of potential confounders. An allelic variant can serve as a proxy for diet and other nutritional factors through its effects on either metabolic processes or consumption behavi

SUBMITTER: Schatzkin A 

PROVIDER: S-EPMC3052774 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature