Lois Vaught has a sweet smile, a soft voice and an aversion to hearing aids. Although she’s deaf, she will not use one.

When you’re 104, you can decide these things for yourself.

But hearing aside, Vaught, the oldest resident of the Friends Nursing Home in Sandy Spring, Maryland, is alert, reads a newspaper every day and responds to questions in writing. She’s among a growing number of centenarians whose lives are being studied by scientists to sort out the mysterious combination of behaviour and genetics that determine why some people live so long.

Vaught’s parents lived into their 90s. She was born and raised on a farm in Indiana, taught school and married a Quaker. She and her late husband never drank alcohol or smoked. She also has maintained the right attitude and diet.

“Before it became popular, she was into healthy cooking. There was never anything fried,” said her only daughter, Ann Larson, who lives near Chicago. “Second, she’s very serene. She doesn’t have huge mood swings or get stressed.”

Researchers look for patterns like these in their quest to understand the genetic and molecular underpinnings of ageing. “The holy grail in the field is finding longevity genes, genes that slow down the rate of aging and reduce susceptibility to age-related diseases,” said Dr Thomas Perls, a physician at Boston University Medical Center who enrolled Vaught in his New England Centenarian Study four years ago.

Perls is seeking volunteers for another five-year, $18 million study — funded by the National Institute on Aging — that looks for common genetic traits and health habits in families with more than two members who have reached 90.

... contd.