Previous studies estimated the maximum human lifespan at 115 years, but biologists at McGill University crunched the numbers again. Their conclusion: if there is a limit to how long humans can live, we haven’t reached it yet.
Published in Nature, Professors Bryan G. Hughes and Siegfried Hekimi credit continual improvements to our quality of life. We have better control of our environment and hygiene, we eat fresh foods all year round, and we have vaccines and advanced medical care. So not only is there no upper limit in sight, there’s also no reason why those extra years won’t be healthy ones.
Just a century ago, the average lifespan for a Canadian born in 1920 was only 60 years. A newborn Canadian today can expect to live 82 years. And whenever the average life expectancy goes up, the maximum lifespan trends upwards with it.
In fact, centenarians are now the fastest growing demographic. And the people who have lived beyond 100 years today didn’t have all the same luxuries as we have from birth, suggesting that younger generations already have the potential for longer lives.
Currently, the Guinness World Record for being the longest lived goes to Jeanne Calment, who died at age 122 in 1997. Ironically, Calment’s longevity is one of the reasons Hughes and Hekimi dispute the finding of a 115-year limit on human lifespan: taking out her record-breaking data point, an outlier compared to her peers, the apparent lifespan plateau was gone.
The original analysis also split the data into two arbitrary time periods to demonstrate a limit, but this can be deceiving. The trouble with segmenting data sets is that they can be manipulated to highlight temporary plateaus or declines, even if the overall trend is upwards.
So while there may be a limit to the human biological clock, or to the resources available to continue improving quality of life, those of us alive today may never live to know what that limit will be.