Scientists want long-lived North-East families to help them find the secret of longevity.

A team at Newcastle University want to hear from families in the region with at least two brothers and sister aged 90 years or over.

The scientists are taking part in a Europe-wide research study into why some people live longer than others.

For the last 50 years life expectancy has increased by two years for every decade and this trend is showing no signs of slowing down.

Now experts in ageing at Newcastle University want to investigate long-lived families as part of the Genetics of Health Ageing (GEHA) study. Ideally, the Tyneside scientists need to recruit 150 families.

The Newcastle team is led by Professor Tom Kirkwood of the university's Institute for Ageing and Health.

Prof Kirkwood, who is one of the world's leading experts on ageing, points to a number of reasons for people living longer.

These include vaccines for the control of disease, which prevent people from dying at a young age.

Better living conditions and good nutrition also mean that we reach old age in better health.

"Previously it was thought that the ageing process was set in stone, but many of the preconceptions about ageing are wrong," said Prof Kirkwood.

"We are not genetically programmed to die, but to survive. This study will aim to investigate the genetic factors that affect lifespan and health in old age.

"We want to try to find out why some families are genetically predisposed to longevity," he added.

Taking part in the study would involve volunteers being visited in their own home by a research nurse.

The nurse would ask questions about health lifestyle and family history.

A blood sample would also be taken and the nurse would carry out a simple physical examination.

Clinical research nurse manager, Karen Barrass, said: "The research team have a lot of experience and understand that some individuals may have health or memory problems, and this does not mean they cannot take part in this important research. Family members or carers are encouraged to be part of the process and can be present at the interview to help."

Families who would like to volunteer to take part in the study should contact Karen Barrass on 0191 256 3391 or karen.barrass@ncl.ac.uk