Dietary assessment and the reliability of nutritional epidemiology research reports.

It is a pleasure to comment on the valuable article by Dahm et al. (1) in this issue of the Journal and to provide my perspective on research needs and opportunities for progress in the challenging nutritional epidemiology research area. In doing so, I would like to first offer a tribute to the late Dr Sheila Rodwell (Bingham), senior author of the article by Dahm et al. For some decades, Dr Bingham provided cutting-edge research on nutritional biomarkers and dietary assessment methodologies and on related epidemiological associations. Her diverse contributions have been vital to progress in the nutritional epidemiological research area, and her leadership will be much missed. Dahm et al. (1) revisit the association between dietary fiber and risk of colorectal cancer in the context of an analysis of data from seven prospective UK cohort studies, with the novel feature that fiber consumption estimates are available from food diaries (also referred to as food records [FRs]). Whereas dietary