EIGHTY-ONE YEARS . That’s 971 months, 29,565 days, or 709,560 hours. It was also the projected life expectancy in Canada last year. With significant advances in nutrition, healthcare, and medicine, it comes as no surprise that this figure is at an all-time high. However, it has recently been brought to the attention of many that this increase is reaching a plateau. In other words, there could be a cap as to how long humans can actually live.
On October 13, 2016 a research group in the Department of Genetics at the Albert Einstein College of Medicine published a paper in Nature entitled “Evidence for a limit to human lifespan.” The group tracked maximum reported ages of death over the years and found that despite having experienced a dramatic increase between the 1970s-1990s, the number began to plateau in the mid-1990s at 115 years. Since then, this number has increased but only by extremely small amounts. Within the study, they also analyzed trends in survivability and noted that the chance of surviving past the age of 100 is no longer substantially increasing.
This finding ignited a storm of debate in the field with members of the scientific community highlighting that the study did not take into account potential advancements in medicine that may occur in the future. Additionally, many were optimistic about the possibility of translating work conducted on prolonging the lifespan of worms and mice to humans. On the other hand, Dr. Jan Vijg, one of the authors of the aforementioned paper, doubts that drugs or tissue engineering would be able to push past the 115 year ceiling. He states that “lifespan is controlled by too many genes” and that “you could maybe plug one of those holes, but there are still another 10,000 other holes springing up.” To this, Dr. Aubrey de Grey, the Chief Science Officer at the Strategies for Engineered Negligible Senescence (SENS) Research Foundation in California, responds: “Unlike a dam, the pressure on the so-far-unplugged leaks actually diminishes as one plugs more and more of them […]The result in this paper is absolutely correct but it says nothing about the potential of future medicine, only the performance of today’s and yesterday’s medicine.”
Since the first paper, a new study has been published, also in Nature. Instead of looking at multiple populations, this paper focused on a group already known for their longevity—Japanese women—and a new projection of maximum human lifespan was put forward at 125 years. The study was aimed directly at the original paper but to Vijg a limit to lifespan “makes a lot of sense” and he “never imagined the paper would stir up so much comment.” Some believe that at this point it is too soon to make conjectures on maximum human lifespan.
Even the concept of life expectancy and what it really represents is a topic that divides many.
Although life expectancy has been on the rise, it’s not really a measure of how long humans can live but rather an indicator that more people are surviving past a certain age, likely due to a number of societal changes such as improvements in healthcare and public sanitation.
There have even been criticisms on whether the question—how old can we age?—is even worth answering. If given the opportunity, would we all want to live longer? If so, just how much could medicine and gene modifications do to achieve this goal? Are there secrets to living longer? Well, according to Jeanne Calment—the oldest documented person to have ever lived (she passed away at the age of 122 in 1997)—there are. When asked in a telephone interview, she advises, “If you can’t do anything about it, don’t worry about it.”
- Life Expectancy. Statistics Canada. Available Online : https://www.statcan.gc.ca/pub/89-645-x/2010001/life-expectancy-esperance-vie-eng.htm
- Whitney CR. “Jeanne Calment, World’s Elder, Dies at 122” 1997 Aug 5. . The New York Times. Available Online: http://www.nytimes.com/1997/08/05/world/jeanne-calment-world-s-elder-dies-at-122.html
- Dong X, Milholland B, Vijg J. “Evidence for a limit to human lifespan”. 13 Oct 2016. Nature. doi:10.1038/nature19793
- “The limits to human lifespan must be respected”. 5 Oc 2016. Nature Editorial. Available Online: http://www.nature.com/news/the-limits-to-human-lifespan-must-be-respected-1.20728
- Geddes L. “Human age limit claim sparks debate”. 5 Oct 2016. Nature.Available Online: https://www.nature.com/news/human-age-limit-claim-sparks-debate-1.20750
- Couzin-Frankel J. “Is there a limit to the human life span?” . 5 Oct 2016. Science. Available Online: http://www.sciencemag.org/news/2016/10/there-limit-human-life-span
- De Beer J, Bardoutsos A, Janssen F. “Maximum human lifespan may increase to 125 years” 28 June 2017. Nature. doi:10.1038/nature22792
- Scutti S. “Living to 125 and beyond: Scientists dispute there’s a limit to our lifespans”. 30 June 2017. Cable News Network (CNN). Available Online : https://www.cnn.com/2017/06/30/health/aging-dispute-humans-live-to-125/index.html