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LONGEVITY
LONGEVITY - NO END IN SITE?
from the desk of Joseph Patrick Jakubal
Research suggests that human lifespans may be increasing without
any clear limit in sight.
Life expectancy has soared in the United States and other industrialized countries. Some researchers
argue that we can sustain that progress, but others think we've stretched our time nearly to its limit
In the 20th century, life expectancy went up a lot while death rates dropped sharply. Today, when
experts try to predict if this trend will keep going in the 21st century, they get very different
results.
Some think life expectancy might only go up a few years, while others believe it could
increase by more than ten years. The reason for these different predictions mostly comes down to
how researchers make their assumptions.
For instance, some experts prefer using "extrapolation", which means they basically extend past trends
into the future. This works well if things stay the same, but it might not be accurate if conditions
change.
Other researchers, like those at the Social Security Administration, argue that
predictions should rely more on expert opinions about future medical breakthroughs, economic
changes, and other factors. However, this method can be subjective since it depends a lot on
personal judgment.
Demographers argue about future life expectancy, but they agree on
what has happened over the last century. Infant mortality in the US dropped sharply thanks to
several key advances:
1) Vaccines and antibiotics stopped deadly diseases like typhoid, measles, and pneumonia.
2) Better sanitation made a huge difference.
3) Improved nutrition helped people resist illness.
4) Even simple changes, like pasteurizing milk in the early 1900s, prevented deadly digestive infections.
It wasn't just children who benefited. Death rates for the elderly fell
84% since 1900. Researchers aren't entirely sure why, but these factors likely helped:
1) People grew up healthier thanks to the improvements above.
2) Medicare provided better care for older adults.
3) New treatments tackled "old age" diseases like diabetes and cancer more effectively.
Demographers care deeply about predicting future life expectancy and death rates. But here iss the key
problem: these predictions are not just about the data itself. If the number of deaths stayed the
same every year, life expectancy would not change. Predictions would be easy.
But death rates change unpredictably. This forces demographers to make
imperfect guesses about the future.
Researchers take two main approaches: 1) Some assume current trends will continue, extending past patterns forward
2) Others adjust the numbers based on their own judgment
No matter which method they choose, "the starting assumptions
always affect the final results".
Lee and Lawrence Carter from the University of Oregon studied U.S. death rates from 1900 to 1989.
They created a model to track the decline and used it to predict future mortality and life
expectancy.
The model works well for "long term" forecasts because it smooths out "short term"
fluctuations - like changes in smoking rates or the impact of AIDS revealing the underlying trend.
In 1992, their model predicted life expectancy would reach 84 years by
2050 (up from 77 years at the time). Later, Lee and Timothy Miller at UC Berkeley updated the
prediction using newer data. The 1992 forecast was remarkably accurate - predicting 76.5 years for
1998, just 0.2 years off the actual number.
With nine more years of data, Lee and Miller raised the 2050 projection
to 85 years.
Another optimistic prediction comes from Vaupel and Jim Oeppen from
Cambridge University. They looked at data from the country with the highest female life expectancy
each year. Back in 1840, that was Sweden, where women lived about 45 years on average. Since then,
different countries like New Zealand and Denmark have had the highest life expectancies at
different times. Currently, Japan has the highest, with men living around 82 years (78 in 2000) and
women around 88 (85 in 2000).
When Vaupel and Oeppen plotted the highest life expectancy numbers from
1840 onward, they found that it increased by about 2.5 years every ten years. They published this
finding in Science in 2002. Vaupel believes this trend will continue, saying that if life expectancy
has been going up steadily at this rate before, it will keep doing so. Based on this rate, women
in the top country (whether Japan or somewhere else) could live to about 97.5 by 2050 and reach
100 by 2060.
The method also gives a way to measure how the U.S. is doing. Some
patriotic Americans might be surprised to find out that the U.S. has never had the highest life
expectancy - it has always been 1 to 10 years behind other countries. If this gap stays similar, by
2050 the U.S. life expectancy would be somewhere between 87.5 and 96.5 years, which is 8 to 17
years longer than it is now.
Lee and Vaupel's approach basically assumes that future trends will follow past patterns - meaning
deaths will keep decreasing at the same rate. For this to happen, medical research needs to keep
making big breakthroughs that help people live longer.
Considering how much data we're getting from
genetics and protein studies, plus all the new discoveries about diseases like cancer and heart disease
at the molecular level, Vaupel argues this is a pretty fair assumption to make.
Even though demographers cannot predict the future perfectly, they
generally agree that life expectancy is increasing. But experts also warn that there are several
major risks that could reverse this trend. Things like environmental damage, wars, economic crises,
or terrorist attacks could suddenly shorten lifespans.
While recent viruses like SARS and West Nile have not caused massive
deaths, researchers like Lee point out that new diseases could be much worse ... HIV has already cut
life expectancy in parts of Africa to levels not seen since the Middle Ages.
The biggest challenge to longer lives might actually come from unhealthy
habits in wealthy nations. In countries like the U.S., rising obesity rates and lack of exercise
could undo medical progress.
Scientists like Goss argue that even advanced genetic treatments might
not be enough to counteract the damage from poor diets and inactive lifestyles. Olshansky warns
that unless Americans start eating better and exercising more, we might actually see life
expectancy go down in the future.
Experts are not sure if people in rich countries will keep gaining
weight and see shorter lifespans, or if they will manage to lose weight and get healthier. But
researcher King believes forecasting methods are improving. He points to Lee's studies as proof,
saying, "The tools we have now are way better, so the field will probably change a lot." Better
models will help demographers figure things out eventually, but it is going to take time ... we will
just have to wait to find out what really happens.
Another study published in the journal *Science* by American researchers
indicates that the maximum age humans can reach has been steadily rising by approximately. one year
per decade over the past 140 years. If this trend continues, it is possible that some individuals
could live to 130 in the near future. Even more promising, advances in medicine and science might
speed up this trend.
The study used detailed population data from Sweden (which is considered
some of the most reliable in the world). Surprisingly, the findings go against "long held" beliefs in
the scientific community that the human body has a fixed lifespan limit, much like a machine wearing
out over time. Many people have assumed that humans simply cannot live past 120, but this research
challenges that idea.
Professor John Wilmoth from UC Berkeley, who led the study, explained
that if there were a biological limit to aging, the increase in maximum lifespan should slow down as
we approach it. Instead, the opposite is happening ... lifespans are increasing at a faster rate.
Wilmoth also states, "We have shown that maximum lifespan is not fixed.
There is no sign that the upward trend is stopping". He criticizes earlier claims about a 115 or 120
year limits, calling them unsupported guesses repeated by scientists without solid evidence.
Historical data shows that in 1860, the oldest recorded individuals were
around 100 years old. By 1960, the maximum age had increased by about five months per decade,
reaching an average of 105. Now, that rate has accelerated to over 13 months per decade.
If this
pattern holds, by 2020, the average maximum age could be around 121, with the oldest individuals
possibly reaching 135. This prediction is based on Jeanne Calment, a French woman who died in
1997 at 122.5 years old (the oldest confirmed case). There may have been older people, however
their ages could not be verified.
UPDATE
Kane Tanaka (117 yrs 66 days) in 2020 was the oldest person that year.
(Listchallenges.com)
Sister Inah Canabarro Lucas, a Brazilian nun held the Guiness World Record holder as the oldest
living person, when she died in April 2025 a month shy of her 117th birthday.
In reality, these two centurians contradict John Wilmoth's
claim, i.e., "if there were a biological limit to aging, the increase in maximum lifespan should slow
down as we approach it".
CONCLUSION
In hindsight ... it "does" seem as though we are hitting a "road block" to age limits.
However,
this is not "conclusive" because maybe the subjects were not the "oldest" people in the world in 2020 & 2025.
This research suggests, however, that we should be concentrating on "quality of life"
versus "quantity of life".
VIDEO: Cancer is a fungus.
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