What Is the Maximum Human Lifespan?
A new study looks at the decline in specific blood markers and uses this to predict the maximum lifespan for humans
122 years and 164 days.
That is the current longevity record for humans. That was the age of the French Jeanne Calment when she passed away on August 4th, 1997.
Since then, no one has even cleared the 120-year mark.
Unless you’re feeling biblical, of course. The patriarch Methuselah holds the longevity record for longest-living human featured in biblical stories with a whopping 969 years. (Although it might have been a mistranslation.) Then, again, I think we can dispute the veracity of this claim…
So, 122 years.
Is that it?
Or can we go further?
We’re certainly trying.
Drugs (such as metformin or rapamycin), supplements (such as resveratrol), blood exchange and/or dilution, custom-made molecules, and stem cells are all being studied for their potential effects on mitigating (some aspects of) aging. Or why not try some fasting or calorie restriction (which may not work as well as you think)?
Many questions about all of these remain, though. Are they effective — if at all — in everyone, or are there good and bad responders? Are the side effects worse than the benefits? Do these interventions actually prolong lifespan in humans? And so on.
Some researchers are pessimistic and claim that we’ve reached the biologically possible peak. Others contest this claim and suggest a certain flexibility in maximal human lifespan.
On the other hand of the spectrum, we have the longevity optimists who are confident that the first 1,000-year old is already walking among us.
Of course, this latter claim relies on imagined advances in longevity research, regenerative medicine, and — if you want to venture even farther into speculative territory — mind uploading, cyborgs, etc.
A new study weighs in on the longevity limit of our biological bodies.
The researchers used data from NHANES surveys 1999–2014, which is:
…a program of studies designed to assess the health and nutritional status of adults and children in the United States.
About 5,000 people are examined as part of this program each year.
The scientists investigated a large, longitudinal dataset of complete blood counts from within this overarching NHANES data. Basically, this is information about the number of blood cells as well as certain markers such as hemoglobin, and so on.
They combined these variables into a single metric, the dynamic organism state indicator (DOSI), and then looked into how this changes with age. (Not unlike previous research that used data mining to find aging clocks in levels of blood proteins.)
And indeed, over the course of a 10-year follow-up, the DOSI was fairly good at predicting chronic age-related diseases. Interestingly, the baseline DOSI was elevated (= bad) in people who engaged in ‘life-shortening’ behaviors such as smoking. The researchers then extrapolated the DOSI data in a few different ways and this
…suggested that the equilibration rate and hence the resilience is gradually lost over time and is expected to vanish (and hence the recovery time to diverge), at some age of ~120–150 y.o.
That’s it, then. 150 years max.
Not entirely. Allow me to quote a substantial chunk from the discussion (bold is mine):
The proximity of the critical point revealed in this work indicates that the apparent human lifespan limit is not likely to be improved by therapies aimed against specific chronic diseases or frailty syndrome. Thus, no dramatic improvement of the maximum lifespan and hence strong life extension is possible by preventing or curing diseases without interception of the aging process, the root cause of the underlying loss of resilience. We do not foresee any laws of nature prohibiting such an intervention. Therefore, further development of the aging model presented in this work may be a step toward experimental demonstration of a dramatic life-extending therapy.
Note the bold sentence fragment. If we let our biology run its course, then — in the best possible conditions — 150 years could be the absolute maximum.
(Of course, ‘let our biology run its course’ is a vague statement. For example, blood pressure medication is widely used. It may also impact your lifespan by protecting you from cardiovascular problems. Is this letting biology run its course, or is this an intervention, or is it an enhancement?)
But, perhaps, we can move beyond treating age-related issues as and when they arise and begin to focus on intervening in the aging process itself.
One could say that age-related problems are symptoms, and aging is the disease.