London, July 13 (IANS): The brains of baby boomers - those born between the years 1946 and 1964 - could hold the key to unlocking the secrets of dementia, scientists believe.

Researchers have begun scanning the brains of 500 members of Britain's longest running birth cohort study, as part of efforts to find a cure for Alzheimer's disease, Telegraph reported.

The subjects were all born in the same week in March 1946 and their physical and mental health has been closely monitored since birth.

Scientists say the wealth of data already held means the study could provide invaluable insights into the progress of dementia, revealing the first signs of disease and pinpointing the risk factors behind it.

Members of the group have been asked if they will donate their brains after they die, in the first major study to track the health of the public "from cradle to grave".

The 500 come from a lifetime study of 5,000 people which has already made major research breakthroughs, uncovering genetic mutations which increase the risk of breast cancer, and simple strength tests to predict life expectancy.

Experts said the new project offered a "rare and exciting" chance to unlock the mysteries behind the disease, which is suffered by one in three elderly Britons over a lifetime.

Age is the greatest risk factor for dementia, so the fact all those in the study were born in the same week, with mental skills tested from the age of eight, means it is the best controlled study of its type, experts said.

"These kinds of studies are almost impossible to start from scratch, so this is a once-in-a-lifetime opportunity to gain insights into dementia from the world's longest running birth cohort study," Eric Karran, director of research at Alzheimer's Research UK, was quoted as saying.