Gene hastens memory loss

A gene already linked to Alzheimer's and heart disease can also cause everyday memory loss in healthy people as they age, say United States researchers.

A study of people aged 55 and older found that nerve cell activity in the front of the brain declined three times faster among those who had a gene called APOE4 than in those who did not.

The findings, presented at the American Association for Geriatric Psychiatry in Orlando, Florida, could allow researchers to understand why some people age faster than others, and let them design drugs to slow the process.

"This gene appears to be very closely related to how a nerve cell can repair itself or survive after different types of insults," said psychiatrist Dr P. Murali Doraiswamy of Duke University, North Carolina.

"If you carry this gene, your nerve cells appear less capable of repairing themselves."

Dr Doraiswamy and colleagues compared the levels of frontal lobe brain activity in 165 healthy people aged between 55 and 85. The frontal lobe is important for memory.

The subjects were then separated depending on whether the APOE4 gene was found.

The study found that brain activity declined 28 per cent in people who had active copies of the gene compared with 9 per cent in those who did not have it.

The gene is found in 25 per cent of the population and has been linked to higher levels of Alzheimer's, cardiovascular disease and memory loss.

Dr Doraiswamy said discovery of the gene could lead to the development of drugs to slow the ageing process, but more experiments were needed to find out what the gene did to cause the brain to age faster.

"We have a way to go and clearly this finding is not going to have any clinical applications right away in people."

A separate study by Duke researchers identified the average age at which people start to develop memory loss - 72 for Alzheimer's and 60 for Parkinson's.

- REUTERS

nzherald.co.nz/health