No Natural Limit to Human Lifespan
Short lifespans may involve more about what we do to our bodies than what our bodies do to us.
We are accustomed to thinking that lifespan hits a certain age, beyond which our bodies inevitably fall apart. Some scientists, though, are thinking seriously that there is no natural reason why humans could not live well past 100, even 150 years or more. Consider that when social security was implemented in America, age 65 was considered ‘old’ enough where beneficiaries were unlikely to need benefits much beyond that. Now, to the consternation of the Social Security Administration, 80 is the new 60, and nonagenarians are increasingly common. Look at some surprising ideas about the reasons for aging, and prospects for extending health and well-being.
Advancing front of old-age human survival (Zuo et al, PNAS). In this paper, five scientists find no reason why human beings must succumb after reaching any particular lifespan.
Old-age mortality decline has driven recent lifespan increases, but there is no agreement about the age pattern of old-age deaths. For example, some argue that old-age deaths should become compressed at advanced ages, and others argue that old-age deaths should become more dispersed with age. Here we show, for five decades in 20 developed countries, that old-age survival follows an advancing front, like a traveling wave. We make and test several predictions that support the existence of this front. Our unexpected result underscores the plasticity of old-age human mortality, with deaths steadily delayed as societies develop, and supports an ongoing increase in the age of transition to disability. We find no evidence of an impending limit to human lifespan.
Mammoth hunt. Mural at La Brea Tar Pits museum.
Hunter-gatherers live nearly as long as we do but with limited access to healthcare (Vybarr Cregan-Reid, The Conversation). We tend to think of outdoor life as the hard life. Those relying on bows and arrows or spears to hunt food, or wandering far afield to gather fruits and nuts, must surely wear out quickly. Maybe not. Maybe their active lifestyle promotes longevity. In this article, Cregan-Reid, a Reader in Environmental Humanities at the University of Kent, argues that the statistics we often hear about “25 year life expectancy” in primitive societies are misleading. Most of the deaths occur in infancy or childhood, he explains. Anyone surviving to adolescence in a hunter-gatherer society has a good chance of living as long as those in civilized societies, to 70 or older, even without modern healthcare – especially if they engaged in physical activity. In fact, the inactivity of many people in modern civilization amounts to ‘fire-fighting’ as health care workers try to delay the consequences of patients’ poor health habits.
Everyone knows that neither group is experiencing optimum conditions for longevity. The top ten causes of death in wealthy countries are dominated by metabolic disorders and cancers. Nearly all of which have strong associations with the lower levels of physical activity in these countries. The multibillion pound healthcare industry that supports modern lifestyles only buys people in wealthy countries a few extra years.
Modern life does have many benefits, but when it persuades us to use transport, sit in a chair at work, or watch TV for extended periods, we increasingly have to turn to medicine for solutions because these habits are killing hundreds of millions of us each year.
With 70% of people in the US on prescription drugs (50% in the UK), it seems that as lifespan inches upwards, disease is skyrocketing. The irony is that many advances in modern medicine are firefighting those very problems that modern life itself has created.
Cregan-Reid is not making a ‘noble savage’ argument that primitive tribes are better off than city folk. People living in modern cities do live longer – just not a lot longer than those without access to modern hospitals, medicines and MRI machines.
Effect of small-sided team sport training and protein intake on muscle mass, physical function and markers of health in older untrained adults: A randomized trial (PLoS One). This study involving 72 senior adults, who were untrained in sports, showed improved muscle mass in those who took protein supplements after some ball games they agreed to play twice a week over 12 weeks. Conclusion:
Thus, team sport training improves functional capacity of untrained older adults and increases leg muscle mass only when ingesting proteins after training. Furthermore, team sport training followed by intake of drink with low protein content does lower fat mass, heart rate at rest and level of systemic inflammation.
Neanderthal healthcare practices crucial to survival (University of York). Neanderthal human beings survived largely due to their own healthcare practices, this article says. They probably used midwives to assist with childbirth, set the broken bones of the injured, and performed other charitable acts to assist those in need.
Lowlanders are no match for Nepal’s Sherpa (Medical Xpress). The physical adaptability of the human body is perhaps best illustrated in the amazing feats of Sherpa, who are accustomed to traveling long distances with heavy loads in the oxygen-poor atmosphere of the Himalayas. The oxygen at 5,000 meters can be half the amount at sea level. A new study by physiologists at the University of British Columbia shows that “their specially adapted muscles give them up to twice the resistance to muscle fatigue of lowlanders.” Dr Chris McNeil thinks, “A better grasp of how Sherpa muscles are able to not only survive but thrive in such a harsh environment could one day lead to exercise or pharmacological interventions and change the lives of countless people.”
We’re not going to live forever in this era of humanity. Ever since the first parents disobeyed God, death was inevitable, no matter how healthy we try to live. Jesus promised eternal life to those who believe in him; “whoever believes in me will never die” (John 11:26), in the sense of separation from God, because “I am the resurrection and the life” (v. 27). The writer of Hebrews said that it is appointed to man to die once, and after that, the judgment (Hebrews 9:27). Saints of God (i.e., believers) can see death not as an end, but as a doorway into a greater life. We believe this by confidence the promises of God, even though we must deal with the empirical realities of decay of the bodies of those loved ones we have buried.
The curse of death at the beginning implies that humans could have lived forever in physical form. If all the body’s repair mechanisms were working perfectly, and if humans had access to the Tree of Life which appeared in the Garden of Eden and will reappear in the new heavens and new earth, then why not? Even under the curse of death, ancients lived for centuries; Methuselah lived to 969 years and died in the year of the great flood. After that, lifespans began a slow decline. We read that Abraham fathered a child at age 100 and died at 175 “in a good old age, an old man and full of years, and was gathered to his people.” (Gen 25:8). Several early Bible characters like Moses did not suffer decline at death: “Moses was 120 years old when he died. His eye was undimmed, and his vigor unabated” (Deuteronomy 34:7).
Sanford’s book examines the impact of mutations that are invisible to stabilizing selection.
In his book Genetic Entropy, geneticist John Sanford showed that the accumulation of mutations, including neutral mutations, could drive Homo sapiens extinct in a relatively short time (not millions of years, a fact that argues against millions of years of human evolution in the past). Dr Sanford spoke on this topic at the NIH recently (18 Oct 2018); we heard that his speech was well received. Each generation adds approximately 100 new mutations to the deteriorating human gene pool. You can see how modern medicine really is in fire-fighting mode. Unless the Creator intervenes (and the book of Revelation shows how He will) humanity is doomed.
Science may be able to extend average lifespan through genetic engineering or other discoveries, but not indefinitely. In the meantime, as individuals, we can make lifestyle choices that improve our odds of living long, healthy lives, with “eyes undimmed and vigor unabated.” We should never assume that those who die young lived poorly, because diseases and accidents can strike without warning. God does not reveal the day of our death, even though King David wrote, “in your book were written, every one of them, the days that were formed for me, when as yet there was none of them” (Psalm 139:16). In His wisdom, God does not reveal that information to us. Good thing; it keeps us on our toes. The soul-winner’s question is ever pressing: “If you died today, are you absolutely certain you would go to heaven?” Follow the signposts on our Site Map.