Modern diets come under scrutiny in major population health study 

Oxford researchers seek 100,000 participants to investigate how changing eating habits affect long-term health 

The long-term health effects of changing diets, including the growing consumption of plant-based meat and dairy alternatives, are the focus of a major new UK population study. 

Researchers at Oxford Population Health are launching EPIC-Oxford 2 to examine how modern dietary patterns affect health and wellbeing.  The study aims to involve around 100,000 people, including 80,000 new volunteers alongside participants from the original EPIC-Oxford research. 

Funded by the Medical Research Council, part of UK Research and Innovation, the project brings together information on diet, lifestyle and health with biological measurements.  Researchers hope to strengthen the evidence available to inform disease prevention and future dietary guidance. 

Recruitment is open to all UK residents aged 18 and over, including people who regularly eat meat, fish and dairy products, as well as those following flexitarian, pescatarian, vegetarian or vegan diets.  Participants complete an online questionnaire taking around 25 minutes, with options to receive a personalised nutrient report, contribute biological samples and complete follow-up questionnaires. 

The project builds on the original EPIC-Oxford study, which begins in the 1990s.  It follows the health of around 65,000 people across the UK and identifies differences in disease risk between dietary groups, including for heart disease, diabetes and some cancers. 

However, the food available today differs considerably from the products on supermarket shelves when the original participants were recruited.  Earlier studies of vegetarian and vegan diets largely predate the widespread availability of modern plant-based meat and dairy alternatives. 

For Keren Papier, Chief Investigator and Senior Nutritional Epidemiologist at Oxford Population Health, this changing food landscape creates a need for updated evidence. “More people in the UK are experimenting with plant-based diets than ever before, but what people are eating today is very different from what they were eating when many of the studies that inform current evidence were conducted,” she says.  “Participants in this study will help us to address many important questions about how modern diets affect long-term health; we are very grateful for their input.” 

Building evidence for prevention 

Oxford Population Health (the Nuffield Department of Population Health at the University of Oxford) investigates the causes and prevention of disease.  The department has around 1000 staff, students and academic visitors working in a number of world-renowned population health research groups, including the Cancer Epidemiology Unit (CEU), Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), and other groups working on public health, health economics, ethics and health record linkage. It is also a key partner in the Oxford University Big Data Institute. 

Growing interest in reducing animal products reflects a combination of health, environmental and ethical concerns.  Meanwhile, debate about ultra-processed foods raises further questions about the composition of diets that share the same broad label. 

The new study examines the benefits and risks of contemporary eating patterns, with researchers collecting detailed information to investigate how food choices relate to health over time.  Alongside identifying differences between groups, the team wants to understand the biological processes that might help explain them. 

Although EPIC-Oxford 2 recruits UK residents, its research questions concern the evidence underpinning dietary advice and population health interventions more broadly.  The study investigates both potential benefits and risks, rather than assuming that all plant-based diets have the same effects. 

“With EPIC-Oxford 2, we want to go beyond describing those differences in disease risk and better understand the biological mechanisms that may explain them,” says Keren. “By combining population-level diet research with molecular studies, we hope to build stronger evidence on how diet affects health and support better disease prevention in the future.”