New Research on Maximum Human Lifespan

Summary: New findings on maximum human lifespan shows that we have an upper limit due to the construction of our bodies and genetic constraints. However, anti-aging scientists may have discovered ways to overcome this limitation. [This article first appeared on the LongevityFacts website. Author: Brady Hartman. This report has been updated in a follow-up article on the upper limit to human lifespan.]

Three new studies show that maximum human lifespan is limited to about 115 – 120 years due to genetic constraints, the construction of our bodies and an increasingly toxic environment.

These studies are hardly the first to conclude there is a maximum human lifespan. However, there may be a way to overcome this limitation.

Studies on Maximum Human Lifespan

The first study was announced in August by a group of Dutch researchers who pegged the maximum human lifespan at 115 years.  This was closely followed by a study by a team of French researchers led Jean-François Toussaint and Adrien Marck from the Paris Descartes University.  Authors Caleb E. Finch, Ph.D. and Edward L. Schneider, MD from the University of Southern California (USC) in Los Angeles also published a report on the topic earlier this year.

Toussaint and Marck on Maximum Human Lifespan

Toussaint, Marck, and company say that mankind has reached their limits in lifespan, height, and athletic potential. Their study – published in October 2017 in the journal Frontiers in Physiology – covered more than 120 years worth of historical information.

The French researchers blame human genetic makeup and an increasingly warmer and toxic planet. They also say that the low-hanging fruit has already been plucked. In other words, the most effective ways to increase maximum human lifespan and vitality – such as improved nutrition and sanitation, combined with antibiotics and vaccinations – has brought us nearly as far as we can go. Moreover, the researchers say that mankind is about to become a victim of its success. Technological progress has brought us longevity gains at the cost of an increasingly toxic environment. Increasing pollution, global warming, and resource depletion will limit maximum human lifespan, as the authors say,

“However, mankind is now the major actor implicated in its own environment alterations.” Adding, “Sapiens alters his ecosystem, while the ecosystem also shapes him in return.” Continuing “Our activities have been implicated as the dominant cause of most environment changes and the recent acceleration could have major impacts on human health, even if some progress has been recently made, such as the increased use of renewable energy.”

The French researchers also say that future medical advancements won’t be able to overcome our genetic limitations and an increasingly toxic environment. Moreover,  coming “artificial enhancements” such as stem cell therapy, lab-grown organs, gene therapy, and medical nanorobots known as nanodocs will be limited in their ability to extend human lifespan due to our genetic makeup and a warmer and more toxic planet.  As the authors say,

“the evolutionary constraints of body design that lead to structural and functional limitations or environmental factors hinder increased progress. The emergence of new major artificial enhancements may be less favorable in light of ever-increasing environmental boundaries.”

Toussaint, Marck, and company point out the constraints of the Hayflick Limit, saying  “Cells have a limited replicative potential depending on their type. “ The duo point out that progressive telomere shortening that leads to cell death and cellular senescence.

Moreover, Toussaint, Marck, and company cite Judith Campisi’s 1996 study, pointing out the types of macromolecular damage that occur as we age, such as DNA damage and free radical damage, saying

“In addition, they [our cells] accumulate damage with aging and replication, causing dysfunctions, while apoptotic and necrotic processes contribute to their gradual loss.” Adding, “Such a process is common in muscle tissues that gradually lose fibers during aging, or among neurons or hematopoietic stem cells, further aggravating their functional decline.”

In conclusion, Toussaint, Marck, and company contradict futurists such as the SENS Foundation’s Aubrey de Grey and Google’s Ray Kurzweil, who prophesize a doubling or tripling of the maximum human lifespan. As the French researchers put it,

“For such reasons, it is meaningless to claim that most human will live for 200–500 years in the near future (de Grey, 2003), thanks to medical or scientific progress, or that ‘within 15 years, we’ll be adding more than a year every year to our remaining life expectancy’ (Kurzweil and Grossman, 2010). Raising false hopes without taking into account that human beings are already extremely ‘optimized’ for lifespan seems inappropriate.”

Dutch Study on Maximum Human Lifespan

In August, Dutch statistician-researchers announced they had discovered the maximum human lifespan using data mining techniques. The researchers, based at Tilburg and Rotterdam’s Erasmus universities, mined data from around 75,000 Dutch people, examining records spanning the last 30 years. The researchers pegged the maximum ceiling for female lifespan at 115.7 years, and men at 114.1 years.

According to a press release announcing the finding, Professor John Einmahl, one of three researchers conducting the study said

“On average, people live longer, but the very oldest among us have not gotten older over the last thirty years,” adding “There is certainly some kind of a wall here. Of course, the average life expectancy has increased,” continuing “Nevertheless, the maximum ceiling itself hasn’t changed.” 

However, Professor Einmahl said there were still some outliers who had exceeded the maximum human lifespan, such as Jeanne Calment who died at the age of 122 years and remains the oldest verified woman to date.

Finch and Schneider on Maximum Human Lifespan

In a peer-reviewed article published earlier this year, authors Caleb E. Finch, Ph.D. a molecular biologist and Edward L. Schneider, MD from the University of Southern California (USC) in Los Angeles suggest that the maximum human lifespan is around 120 years. The authors add that while medical advancements will help us live longer, the trends show they will not help us live much beyond this upper limit, saying

“the faster acceleration of mortality has continued to rectangularize the survival curve, with little to no change in the maximum lifespan since 1980.”

Finch and Schneider have appeared on LongevityFacts before, in a report covering their air pollution study. Caleb E. Finch, Ph.D., is the ARCO-Kieschnick Professor of Gerontology at USC’s Davis School of Gerontology. His coauthor Edward L. Schneider, MD is a Professor of Medicine, Professor of Gerontology, and Professor of Biological Sciences at the USC Keck School of Medicine.

Increase in Average, Not Maximum Human Lifespan

The USC researchers published their findings in the article “The Future of Old Age,” as part of the Brocklehurst compendium. The authors examine historical changes in our lifespan, and note that average human lifespan has more than doubled in the previous 200 years. Finch and Schneider implicate the improvements in nutrition, sanitation, and healthcare as the reasons for the increases in average human lifespan.

Blame it on Gompertz

Even with medical advances, our death rates accelerate after age 40, doubling every 7 to 8 years. The authors attribute these increases in death rates to the Gompertz–Makeham Law of Mortality which states that the human mortality rate is the sum of an age-independent Makeham component, plus the Gompertz component which increases exponentially with age. Scottish actuary Benjamin Gompertz first described these age-related increases in death rates in 1825.

As the US Gompertz chart above shows, improvements in medicine have reduced infections as a cause of early-age mortality and mortality at ages 10 to 40 years approached a minimum below 0.1% per year. Finch and Schneider even suggest that “Those born most recently may now have an even lower mortality of 0.02%/year (2/10,000). ” This historically low baseline mortality represents the Makeham component which consists of deaths from congenital defects, accidents, and rare familial diseases.

The decline in the human mortality rate before the 1950s was primarily due to a decrease in the Makeham mortality component, while the age-dependent Gompertz mortality component was surprisingly stable. A new trend has started since the 1950s,  in which we have enjoyed reduced mortality rates at advanced ages and a “rectangularization” of the survival curve.

Because of its excellent historical database, the authors used data from Sweden where mortality rates were high in 1800. Although the rates were high due to a 10% to 30% infant mortality rate, young adults at the time had a 1% yearly mortality rate. After the age of 40, adults in Sweden and all other countries show accelerating mortality rates, which Finch and Schneider say are a “basic manifestation of aging,” and demonstrate the existence of underlying biological processes that cause aging.

The USC authors say that improvements in medical care increase the average but not the maximum human lifespan. In other words, as medical care improved over the decades, the mortality curves got progressively steeper,  saying

“paradoxically, as life spans have increased, the rates of mortality acceleration have also increased.”

Finch and Schneider say that the steepening of the mortality curves indicate the presence of a maximum human lifespan, saying

“From these data on mortality rates, it can be calculated that the maximum human lifespans are 120 for women and 113 for men, which are very close to the reported records. “

Reversing Aging

Finch and Schneider are proponents of the geroscience hypothesis, the belief that aging can be controlled, saying

“Laboratory models have amply documented that every aspect of aging can be manipulated, from DNA damage to cross-linking of connective tissue collagen and elastin to ovarian egg cell loss to arterial lipids to brain amyloid levels. In addition to food intake and exercise, aging processes can be manipulated by regulating gene activity without changing DNA sequence.”

Unlike the French team, Finch and Schneider are optimistic that aging can be reversed or slowed.

Bottom Line on Maximum Human Lifespan

The three studies say that despite the advances in medical care, the maximum human lifespan is around 120 years. Medical science may eventually find ways to beat back the multiple diseases of aging, such as diabetes, heart disease, cancer and Alzheimer’s disease. However, the compression of morbidity concept states that these ‘cures’ will not increase the maximum human lifespan, and instead only serve to delay the onset of these diseases, pushing them into the last years of our life.

Overcoming the maximum human lifespan of around 120 years will be a tall order for geroscientists. It will most likely require a powerful combination of regenerative medicine, such as senolytic therapy,  stem cell therapy, combined with gene therapy that resets the genetic clock in our brain as well as the epigenetic clock in our body.

Moreover, unless we are lucky like Jeanne Clement, most likely we will need to have a healthy diet,  and breathe clean air and eat food untainted by heavy metals and other industrial wastes. Geroprotectors such as metformin, rapamycin, and nicotinamide mononucleotide (NMN) may help us live longer lives on average, but it remains to be seen if they extend the maximum human lifespan.

Related: Learn more in this follow-up article on the upper limit to human lifespan.

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References

Marck Adrien, Antero Juliana, Berthelot Geoffroy, Saulière Guillaume, Jancovici Jean-Marc, Masson-Delmotte Valérie, Boeuf Gilles, Spedding Michael, Le Bourg Éric, Toussaint Jean-François. “Are We Reaching the Limits of Homo sapiens?” Frontiers in Physiology, Vol 8, 2017, p812. DOI: 10.3389/fphys.2017.00812. Link to article.

Hayflick, L.  “The limited in vitro lifetime of human diploid cell strains.” Exp. Cell Res. 37, 614–636. (1965). doi: 10.1016/0014-4827(65)90211-9

de Grey, A.  “Foreseeable and more distant rejuvenation therapies,” in Aging Interventions and Therapies, ed S. I. S. Rattan. Singapore: World Scientific Publishers, 379–395 (2003).

Kurzweil, R., and Grossman, T.  “Bridges to life,” in The Future of Aging, eds G. M Fahy, D. M. D West, L. S. Coles, and S. B. Harris. Springer, 3–22 (2010).

AFP press release. “Dutch scientists say human lifespan has limits.” via MedicalXpress.com, August 31, 2017. © 2017 AFP. Link to article.

Finch CE, Schneider EL, “The Future of Old Age.” Copyright © 2017 by Elsevier, Inc. ISBN: 978-0-7020-6185-1

Disclaimer

Diagnosis, Treatment, and Advice:  This article is intended for educational and informational purposes only and is not a substitute for qualified, professional medical advice.  The information and opinions provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Consult a qualified and licensed physician for the diagnosis and treatment of any and all medical conditions. Experimental therapies carry a much higher risk than FDA-approved ones. Call 911, or an equivalent emergency hotline number, for all medical emergencies. As well, consult a licensed, qualified physician before changing your diet, supplement or exercise programs.  Photos, Endorsements, & External Links:  This article is not intended to endorse organizations, companies, or their products. Links to external websites, mention or depiction of company names or brands, are intended for illustration only and do not constitute endorsements.

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