Purpose: The Oxford WebQ is a web-based 24-h dietary assessment method which has been used in UK Biobank and other large prospective studies. The food composition table used to calculate nutrient intakes has recently been replaced with the UK Nutrient Databank, which has food composition data closer in time to when participants completed the questionnaire, and new dietary variables were incorporated. Here we describe the updated version of the Oxford WebQ questionnaire nutrient calculation, and compare nutrient intakes with the previous version used.
Methods: 207,144 UK Biobank participants completed ≥ 1 Oxford WebQs, and means and standard deviations of nutrient intakes were averaged for all completed 24-h dietary assessments. Spearman correlations and weighted kappa statistics were used to compare the re-classification and agreement of nutrient intakes between the two versions.
Results: 35 new nutrients were incorporated in the updated version. Compared to the previous version, most nutrients were very similar in the updated version except for a few nutrients which showed a difference of > 10%: lower with the new version for trans-fat (- 20%), and vitamin C (- 15%), but higher for retinol (+ 42%), vitamin D (+ 26%) and vitamin E (+ 20%). Most participants were in the same (> 60%) or adjacent (> 90%) quintile of intake for the two versions. Except for trans-fat (r = 0.58, κ = 0.42), very high correlations were found between the nutrients calculated using the two versions (r > 0.79 and κ > 0.60).
Conclusion: Small absolute differences in nutrient intakes were observed between the two versions, and the ranking of individuals was minimally affected, except for trans-fat.
Mediating mechanisms linking anthropometric, lifestyle and dietary risk factors with cancer risk
The mediating mechanisms linking anthropometric and lifestyle risk factors with cancer development and survival remain unclear. We aim to investigate the potential mediating roles of metabolic factors (including biomarkers and intermediate conditions and diseases) on the association between risk factors (e.g. fat mass, diet, physical activity) and subsequent cancer diagnosis, death and survival by cancer type. The proposed project aims to understand the mechanisms that underpin the association of risk factors with cancer development and progression, which is consistent with UK Biobank's mission of health-related research that is in the interest of the public good. In the first stage of this project we will run prospective analyses to assess the associations of potential risk factors with risk of, and death from, specific cancers. If there are sufficient cases and available information on tumour characteristics, we will split tumours into subtypes. We will also assess the association between the potential risk factors and each of the possible mediators, as well as the prospective associations between the mediators and cancer risk. Finally, we will estimate the mediation effects of the individual mediators in the associations between risk factors and cancer risk. We intend to include all participants of the UK Biobank cohort.
|Dr Aurora Perez-Cornago
|University of Oxford