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This is part of a regular series on aging well.
The rock stars of the seniors set are running marathons in their 80s and cooking feasts for their families well into their 90s. While their friends succumb to dementia and other chronic diseases, they take few medications and remain sharp as tacks. They are the "Wellderly" – and scientists are determined to find out what makes them tick.
Since 2007, the Wellderly Study in the United States has enrolled more than 1,400 people between the ages of 80 and 105 who have never developed any chronic medical conditions or diseases, including cancer, stroke, Alzheimer's, Parkinson's disease, diabetes and heart attack.
Initial results from the ongoing study were published last month in the journal Cell. After combing through participants' genome sequences for eight years, researchers detected common and rare gene variants that protect against mental decline, which may in turn lead to better physical health, according to scientists at Scripps Translational Science Institute (STSI) in La Jolla, Calif.
The researchers compared the genomes of 511 Wellderly individuals with those of 686 typical adults from a separate study.
The Wellderly group had a significantly lower genetic risk for Alzheimer's and coronary artery disease. However, the researchers found no difference between the two groups in genetic risk for cancer, stroke or Type 2 diabetes.
"We didn't find a silver bullet for healthy longevity," said Ali Torkamani, director of genome informatics at STSI and one of the study's co-authors. "Instead, we found weaker signals among common as well as rare [gene] variant sites, which collectively suggest that protection against cognitive decline contributes to healthy aging."
Protective behaviours and other genetic characteristics may increase resistance to disease in the Wellderly, the researchers hypothesized.
Compared to others in their age group, the Wellderly were more physically active, slightly leaner on average and had attained a significantly higher level of education.
John Rawlings, a nonagenarian participant in the study, plays softball regularly. An avid reader, Rawlings, a Second World War veteran, took up the sport in his 70s. He doesn't plan to slow down any time soon.
"When I turned 90, they said, 'Let's have a big party,'" Rawlings said. "I told them, 'You'd better wait until I turn 100.'"
Fewer than half of Canadians live to the age of 85, and of those, only a minority do not suffer from major diseases such as cancer, diabetes or Alzheimer's. Members of this select group may be candidates for the Super-Seniors Study, launched in 2015 and funded by the Canadian Cancer Society Research Institute and Canadian Institutes of Health Research. Findings from studies such as these may not help the rest of us in the short term. But down the road, as scientists continue to identify variants linked to healthy aging, "maybe that can add to the body of knowledge which will eventually let all of us live to an advanced age and be healthy," Torkamani said.