Diet and disease: a comprehensive investigation of the impact of plant-based diets on long-term health
2025/20
background
Plant-based diets with limited or no animal-sourced products are widely recommended for purported health and environmental benefits. While evidence for the relatively low environmental impact of plant-based diets is clear, the evidence on the long-term health impacts of plant-based diets is sparse, and existing studies have suggested both health benefits and risks. For example, evidence from the EPIC-Oxford cohort and other studies has shown that vegetarians and vegans have lower risk of heart disease, diabetes and diverticular disease, but also higher risk of fractures and haemorrhagic stroke. The relative risks of many other health outcomes remain unknown, partly due to limited data on vegetarians and vegans in most studies. The EPIC-Oxford study is a prospective cohort with up to 30 years of follow-up on 65,000 people living in the UK, half of whom do not eat meat. The study thus provides a unique opportunity to address this question of interest. The UK Biobank is a prospective study of 500,000 people in the UK, including 10,000 pescatarians and 7000 vegetarians.
The overall aim of this DPhil project is to conduct a comprehensive investigation of plant-based diets (e.g., low meat, pescatarian, vegetarian and vegan) and health outcomes in these two UK cohorts, and to understand the possible aetiology of any differences in health outcomes. Specifically, the work will involve working with health records though hospital linkage, cancer and death registries, including potentially investigating the healthcare costs associated with following plant-based diets. It will also involve examining relevant biomarkers (traditional clinical biomarkers and novel technologies such as proteomics) by vegetarian diet group and related dietary factors, using available data from EPIC-Oxford, EPIC-Europe and UK Biobank. The work may also involve genetic approaches (Mendelian randomisation) to assess the causal relevance of selected biomarkers and outcomes of interest.
RESEARCH EXPERIENCE, RESEARCH METHODS AND TRAINING
The student will perform a literature review on the topic, and plan and conduct statistical analyses using large-scale datasets. The student will also be expected to present the results in internal meetings, as well as at national and international conferences, and to write papers for publication in peer-reviewed journals.
FIELD WORK, SECONDMENTS, INDUSTRY PLACEMENTS AND TRAINING
Support and training for specific research methods and statistical analyses will be provided within the department. There will also be an opportunity to collaborate with external researchers within the EPIC network across Europe.
PROSPECTIVE STUDENT
The ideal candidate will have strong quantitative skills and postgraduate level training in epidemiology, statistics or public health. The project will suit someone with an interest in nutritional or chronic disease epidemiology.