521,457 healthy adults, mostly aged 35–70 years, were enrolled in 23 centres in ten European countries: Denmark (11%), France (14%), Germany (10%), Greece (5%), Italy (9%), The Netherlands (8%), Norway (7%), Spain (8%), Sweden (10%) and the United Kingdom (17%).
One UK centre (Oxford) recruited 27,000 vegetarians and vegans; this subgroup forms the largest study of this dietary group.
The main prospective data collected are standardised dietary questionnaires (self-administered or interview-based), seven-day food diaries, blood samples and anthropometric measurements, such as body mass index and waist-to-hip ratio.
Current analyses are focusing particularly on stomach, colorectal, breast, prostate and lung cancers.
The different dietary patterns in the different countries should enable reliable associations to be made between particular diets and cancers.