Scientists close in on centenarians’ ‘secret’

Living to 100 – it’s a prospect that excites some and scares others. One thing is for certain, though, more and more of us are doing it. Such are the advances that have been made in nutrition, hygiene and healthcare over the past century that living to 100 is no longer rare.

I have a distinct recollection of a day in 1976 when my mum declared she absolutely did not want to live to 100. She would have been 51 at the time. I was about to turn 11. As a kid untarnished by the travails of adulthood, I couldn’t understand. How could you not want to live for as long as possible?

Now that I’m 58, with dodgy knees, a crook back and mental health issues, I’m not quite so nonplussed. Mum had likely seen the struggles that some of the elderly people in her life had endured earlier in her life. I certainly hadn’t at that stage.

In any case, with life expectancy across the world having doubled since 1900, more of us are reaching that celebrated/dreaded age. What has remained a mystery, though, has been the question of why some end up living to 100 while others don’t.

Is there a secret to reaching 100?

Now, researchers at the Tufts Medical Centre and Boston University School of Medicine may have unlocked the secret – immunity. The researchers have published their findings in a study in the prestigious medical journal Lancet. Centenarians, it seems, possess unique immune cell composition and activity. This gives them a highly-functional immune system and allows them to live longer.

Dr Tanya Karagiannis, a senior bioinformatician at Tufts Medical Center and lead author of study, explained the idea behind the study.

“Many centenarians experience delays in the onset of ageing-related disease and this suggests the presence of an elite immunity that continues to remain highly functional even at extreme old age,” she said.

Our immune system changes as we age. The makeup of cells and their function transform, and it is these changes that can lead to ageing-related diseases. The analysis conducted by Dr Karagiannis and her team identified unique cell type-specific compositional and transcriptional changes found only in centenarians that reflect normal immune response.

Additionally, the researchers found that centenarians “harbour unique, highly functional immune systems that have successfully adapted to a history of insults allowing for the achievement of exceptional longevity.”

(The term ‘insult’ here refers to injury, irritation or trauma, not someone yelling abuse at their immune system!)

What does this mean?

These findings are interesting, but what do they mean in practical terms? As with much scientific research, the immediate benefits are not yet crystal clear. However, Dr Karagiannis believes the study takes us one step closer to being able to “define the protective drivers of extreme longevity that provides the beneficial health outcome observed in these individuals.”

The key to creating better health outcomes through this research will be in identifying the mechanisms involved.

Kathleen Cameron, from the National Council on Aging’s Centre for Healthy Aging in the US, described the findings as promising. “If we can determine what is creating this immune resilience for those who live over 100, that can lead to treatments that can help people live longer.”

Recent population research suggests that by 2050, 3.7 million people in the world will be centenarians. Compare that to the estimated 450,000 centenarians globally in 2015.

As more breakthroughs are made in medical science, the number will only get bigger. The new research done by Dr Karagiannis and her team may help more of us not only reach 100 but remain relatively healthy when we get there.

Mum passed away at age 93, so she achieved her aim of not wanting to live to 100! But had she known of the latest medical advances she might have changed her mind.

How old are you? How do you feel about living to 100? Let us know your thoughts in the comments section below.

Also read: Five foods with anti-ageing properties