Older twins hold the key to ageing well

Around 300 sets of twins who are 65 or older will take part in one of the largest studies of brain ageing ever undertaken in Australia.

The study will involve 150 sets of identical twins, a similar number of non-identical twins, and the siblings of both groups.

University of New South Wales (UNSW) researchers are carrying out the study, which has the potential to discover new genes involved in cognitive decline or resilience.

"Even though we have twins that are identical, there are vast differences between them," said UNSW Professor Perminder Sachdev, from the School of Psychiatry, who is the team leader on the project. "By studying twins, we will be able to better determine which influences on the ageing process are genetic and which are environmental.

"Over time, the expression of that same DNA material varies depending on different influences in the environment," he said.

"Our study will measure many environmental influences, but in particular: lifetime physical and mental activity, physical and psychological trauma, loss of parent early in life, later losses and life events, early-life socioeconomic environment, alcohol and drug use, occupational exposure, and nutrition," he said. "It will also determine how biological factors such as hypertension and antioxidant levels interact with genes to influence brain ageing."

There will be three clinical assessments over a four year period, during which participants will be asked to provide a blood sample, have a MRI brain scan and answer questions about their health, lifestyle, memory and thinking.

"This research is unique because we're the first in Australia to use twins in this sort of work and because of the comprehensiveness of the assessments," said Dr Julian Trollor, co-investigator on this project and UNSW Senior Research Fellow on the Brain and Ageing Program. "Such a study will allow design of interventions with real potential to impact on ageing."

The researchers hope the study could eventually be a longitudinal one, where they follow the same group for many years.

"We hope the results might eventually be able to be used in a preventative manner, although it's a long way off yet," said Dr Trollor. "You might be able to test for a gene. If that gene is undesirable, then a drug could be used to counteract its effect."

66-year-old identical twins David and Denis Lynch from Sydney's East are enrolled in the four-year program.

"This information can be broadened out to the whole community and we're happy to volunteer, as it's going to be of benefit to many people in the long run," said David, the older of the two, who lives in Woollahra and speaks to his twin every day.

"The results are kept from you, but there are benefits in taking part," said Denis of Rose Bay. "If there are any medical difficulties which are uncovered during the tests, we have agreed to have these forwarded onto our own doctor."

Two million dollars in funding has been awarded to the researchers from a joint National Health and Medical Research Council (NHMRC) and Australian Research Council (ARC) grant of the Ageing Well, Ageing Productively Program.