Diet, lifestyle and biological determinants of health and disease: the EPIC-Norfolk population study

As the population ages, a major challenge is how we can maintain good health and prevent disability so older people can continue having fulfilling lives and making active contributions. To do this, we need to understand what happens when people age, what the major diseases are which affect them and which lead to disability and what we can do to prevent disease and promote good health and function in later life. EPIC-Norfolk is a study of 25,639 men and women aged 40-79 years when it started in 1993 who have contributed detailed information on lifestyle, particularly diet, physical activity, psychosocial factors, and health and who have been followed up to the present. We have already learnt much about how small differences in these factors can influence disease risk and longevity. We wish to continue to follow up this population now aged 55-94 years, to see how their health changes over time. We will be able to examine what characterises individuals who develop conditions such as heart disease, cancers, diabetes, arthritis, lung and bowel diseases and Parkinsons. We will also conduct re-examinations to measure physical, mental, visual and hearing function to identify those who are ageing well and relate these to earlier lifestyles and biological measures. Results will inform the development and testing of interventions, for example, changing physical activity or dietary patterns, that may prevent disease and improve physical or mental function in older people. The detailed biological information from blood samples available in the participants including genetic profiling willl also help us understand the underlying biological mechanisms of disease which may lead to new treatments. This work will help us understand the processes involved in healthy ageing and to understand what we can to promote health and well being in middle and later life.

EPIC-Norfolk is a prospective population study of 25,639 men and women aged 40-79 years resident in East Anglia recruited in 1993-97 and followed up to the present. The overall goal is to identify behavioural and biological determinants of health and chronic disease to inform interventions to improve health in later life. Particular investment has been made in better measurement of lifestyle, in particular diet and physical activity, biological phenotyping including genetics and in capturing a range of health outcomes. Extensive data already collected on the cohort includes social, psychosocial, family history, medical, anthropometric, lifestyle including detailed physical activity and dietary information with repeated 7 day diaries and food frequency questionnaires; blood lipids, glycated haemoglobin, plasma vitamin C, thyroid function and bone heel ultrasound measures. A biological bank of blood and urine samples has been established for genetic and biochemical profiling with whole genome data already available on 4000 individuals. Specific strengths of this British prospective study include the population based recruitment and size with substantial numbers of women as well as men, and older persons, and wide urban/rural and social class variations. The geographical location also enables follow up for a range of endpoints not easily available in other cohorts including diabetes, musculoskeletal, neurological and gastrointestinal conditions. We have already demonstrated the value of this approach in understanding disease aetiology, in particular, the emphasis on better exposure and endpoint measurement, in published results (over 300 publications since 2006). We are now well positioned to build on this resource to characterise the longitudinal trajectory of a population as it ages and examine determinants of healthy ageing as well as chronic disease to enable appropriate interventions in the population.

The current proposal is to provide core infrastructural support to continue follow up of the cohort for health endpoints, enable a repeat survey of the cohort for objective physical and cognitive functional measures and visual health, maintain and update the data bases and biological banks, and to continue examining hypotheses on determinants of health. The cohort size, providing sufficient power to examine disease endpoints, improved accuracy of measurement of diet, physical activity and other exposures, and availability of biologic markers and improved endpoint ascertainment will enable better elucidation of the qualitative and quantitative relationship between lifestyle and biological variables and health outcomes relevant in ageing populations. We will also explore the interaction of genetic predisposition with environmental factors for health outcomes.