Hundreds of people are being recruited for a major study into how people stay healthy into old age. 

The Newcastle 85+ research will try to identify the relevant biological, social and medical factors. 

The study, hailed as the most detailed yet on the subject, is being carried out by Newcastle University's Institute for Ageing and Health. 

It aims to recruit 800 people who celebrate their 85th birthday this year to take part in the study. 

Researchers will look at the biological process of ageing and the impact of factors like nutrition and lifestyle. 

Senior clinical research fellow Dr Joanna Collerton said: "A striking feature of biological ageing is its marked variability between individuals and the first step in this study will be to determine what is a healthy 85-year-old. 

"Relatively little information is available about the health of people in this age group so this project will enable us to study in detail what is happening to the health of the very old. 

"This is important not only because people of 85 years and over make up the fastest growing sector of the population but also for what it will tell us about the ageing process and the factors that affect it." 

The study, which is receiving funding from the Medical Research Council, has been developed during a one-year pilot study on a sample of 116 people.