Humans live long lives compared to most species on the planet, but we are by no means the species that lives longest. The ginkgo biloba can live for over 1,000 years, and the deep sea sponge is estimated to live for more than 10,000 years. Hydra (a relative of the jellyfish) live to around 1,400 years, and the Greenland shark can live to be an estimated around 400 years old.
Humans may be starting to live longer, however. The number of centenarians is on the rise. And the number of supercentenarians (those over 110 years of age) is bumping up, too. So, could we live longer than we currently do?
There are limits to longevity
In the developed world we generally live for another 23 years after hitting 60, but for the last two decades of our lives most humans begin to decline, both physically and mentally.
Dr. Jan Vijg, PhD, believes that living longer and healthier can increase the length of our lives, but that the upper limit is about 115, after which our bodies will simply collapse and die. According to Vijg, maximal lifespan has a hard ceiling, which he concluded using data from the Human Mortality Database. It suggests that since 1900, survival improvements for people 100 or over have reached their limit, and that the chance of anyone in the near future living over 125 anywhere in the world is only one in 10,000.
Longer lifespans are possible
Dr. Judith Campisi, PhD, believes that the aging process is becoming postponed, but is skeptical of the timing. She points out that there are many genes involved in aging, and so it will be hard to modify them in the near future. Dr. Tom Kirkwood, PhD, on the other hand, says, “The idea that life is limited does not really fit with what we already know about the biology of the aging process. There is no set program for aging.”
Aging appears to be a function of evolutionary neglect, (i.e., evolution has no reason to prevent it). It’s entirely possible that, at some point in the future, how we get older will be understood, slowed, and stopped — or even reversed.
How will we live longer?
We are going to live longer, but it will happen in stages. Decades from now, scientists will gain a fresh understanding of the principles of cell biology that will allow age-specific pathways to be changed to benefit our longevity. We are already benefiting from a better understanding of key diseases related to aging. Cancer, caused by multiple different factors, will no longer be the death sentence it once was. In fact, within two decades, cancer will not be among the leading causes of death. Immunotherapies are constantly improving, and early diagnosis of cancer will soon become the norm.
What’s next?
The addition of 30 years or so to average lifespans over the next 20 to 30 years has the potential to change life — and society — in dramatic ways. As with so much technology in recent years, living longer is becoming a possibility. Though the ways in which it will happen are unclear, it will happen. We just need to be patient.