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Brew: Some of you may have heard that taller people’s
hearts have to work harder, or that their lungs are
bigger so they have to use more energy to just breathe.
You may also have heard that tall people
tend to live shorter lives than their shorter
counterparts, but if that’s true, why?
For the most part, in nature, the larger a
creature is, the longer it tends to live.
Compare the 12 month lifespan of a black rat, one
of the smaller animals on Earth, to the 90 year
lifespan of a blue whale, the literal largest living
creature to ever exist on Earth, and it seems like
tall people should be not only growing more than
their shorter friends, but also living longer.
It’s been said that the shorter you
are, the closer you are to hell.
So could hell be giving short people a longer life?
Maybe it should be “the taller you
are, the closer you are to the grave.”
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And with that out of the way,
Let’s get into it!
So, do tall people lead shorter lives?
Do they actually die earlier than shorter people?
Well, multiple studies have shown a relationship
between increased height, and reduced life expectancy.
One, published in 2017, looked at over 3000 NBA
and ABA basketball players from 1920 to 2017, and
found that generally, the shortest players lived
the longest, with an average lifespan of 75 years,
while the top 5% of tallest players lived the
shortest, with an average lifespan of 56 years.
Another, looking at the same relationship using military
conscripts between 1866 and 1915 from an inland village
in Sardinia, Italy, found that shorter recruits lived,
on average, 2 years longer than their taller comrades.
Men lost around 0.23 years for every extra centimeter (~25/64 in)
of height at 70 years old above the average!
That’s almost a quarter of a year for just a centimeter!
Maybe caffeine stunting growth is actually a good thing!?
A third study, looked at 373 male veterans from the Veterans
Administration in San Diego who died in between 1984 and 1988.
Researchers discovered that men who were under 5’6” (~167cm) lived
4.95 years longer on average than men taller than that.
What’s more is that men who were shorter than 5’5” (~165cm)
lived 7.46 years longer than men taller than 5’9”.
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I will mention that most research across all
of the sciences, especially retrospective
studies, usually only use men as participants.
More recent studies have been looking at this
relationship with gender as a factor as well.
That being said, the data is very real, if a little skewed.
But the question remains, why are taller people
dying earlier than their shorter counterparts?
Let’s take a look at some of the tallest people
in history and see what they died of to get an
idea of what could be behind this phenomenon.
The tallest person ever was a
fellah by the name of Robert Wadlow.
He was born in 1918 in Illinois a pretty regular baby,
but by age 8 he had already grown past 5 foot 11 inches (~1.80m).
Into his adulthood, his stature
cracked a whopping 8 foot 11 inches! (2.71m)
He passed away at the young age of 22 from a septic
blister on his right leg from a botched brace in his leg.
Hey, how about André the Giant?
He was pretty big.
Born in 1946, he was diagnosed with acromegaly
and grew to 6’6” (1.98m) by the time he was 15.
At his death he was as tall as 7’4” (2.23m), and passed
away from congestive heart failure at the age of 46.
Their stories don’t actually help us much though, both
André and Robert had conditions that made them grow so tall.
Robert had what’s called pituitary gigantism, which as
the name suggests, makes people grow to a “gigantic” size.
André, likewise, was diagnosed with
acromegaly which triggers excessive growth.
Basically, their conditions affected their
health, which excludes them from our data.
We’re looking at why tall people, with no notable
health problems, tend to die earlier than short people.
The tallest people in history without growth related
disorders are Angus MacAskill, 7’8” (2.33m), who died age
37 from Brain Fever, Manute Bol, 7’7” (2.31m), who died
age 47 from Stevens-Johnson syndrome, and Neil
Fingleton, 7’7” (2.31m), who died age 36 from heart failure.
You may remember Neil from Game of Thrones as Mag the Mighty.
In recent news, Igor Vovkovinskiy, the tallest
living man in the US since 2010 has just
passed away August 20th at the age of 38.
Standing at a sky-scraping 7 foot 8 inches (2.33m), he spent his
last day with his family, eating cake and drinking Fanta.
Y’know, I really hope that he had a good day.
Anyway, back to the episode!
It’s hard to do research on subjects like
these, because people are individuals.
They have their own habits, good or bad, they may have
genetic illnesses, there are factors at play in an
individual's life that make them bad for a scientific study.
So, to get any answers, we need a big sample size.
Lucky for us, researchers love large sample sizes,
because it means they get more accurate data,
they can better account for outliers, and their
colleagues can’t call their work...“inadequate”.
Yoon Jin Choi and other researchers collected data
from a national claim survey of over 22 million Korean
adults, and in their 5 year follow up period, just
under 800,000 of them were diagnosed with cancer.
They found height to be positively associated
with cancers in all of these sites.
Which means that there was a higher ratio of
individuals diagnosed with all types of cancer
in the tallest portion of the population.
But how could height make you more vulnerable to cancer?
Well, an article by Dr. Leonard Nunney found that for every 10 cm (~4”),
or 4ish inches, above an average of 5’3” (162cm) for women and
5’7” (175cm) for men, cancer risk increased by a whopping 10%!
He argues that one possible explanation could
be that taller individuals have a higher
cell division rate than shorter people.
He notes that this could come from the
relationship between a hormone called IGF-1,
or Insulin-like Growth Factor, and cancer.
This hormone, along with Growth Hormone,
or GH, promote bone and tissue growth.
These hormones increase gradually over one’s childhood to peak
in puberty, then generally drop again once you’re an adult.
Yet another study found that there is a slight increase
in risk of cancer due to higher IGF-1 levels in adulthood.
This is corroborated by the fact that individuals
with less IGF-1 actually have protection from cancer.
So that’s cancer, but what about other illnesses?
Like, heart disease?
If you think about it, tall people’s hearts have
to pump harder to counteract gravity, right?
Not to mention that since their bodies are larger,
the distance blood needs to move is further.
So maybe tall people have heart problems?
It’s actually fascinating, as we saw, being tall has been
linked to higher risks of developing cancer, but being tall
has also been linked to lower risks of cardiovascular disease.
Being tall increases cancer risk, but
being short increases cardiovascular risk.
How wild is that?
When researchers identified 180 spots on the human genome
that change according to height, they wanted to see which
genetic traits also coded for high risks of heart disease.
They found that for every 2.5 inches (6.35cm) shorter one is from
the average, the risk of heart disease increases by 13.5%.
The shorter you are, the higher the risk.
Another Korean study that observed
over 16 million individuals by
Dr. Chan Soon Park and others, found that, over
the course of their 9 year follow up period,
there was a negative relationship between height
and heart attacks, heart failure, and strokes.
Meaning that their taller participants were less often being
diagnosed with heart issues than their shorter counterparts.
Researchers note that “tall stature may be associated
with a low mortality from CVD” but that doesn't
mean that tall people don’t have heart disease.
It just means that tall people were dying
of other things more often heart disease.
So then what does this mean?
Are tall people actually better off than shorter people?
Well, no.
Tall people still live shorter lives on average.
While tall people may have a lowered risk of
heart attack, heart failure, and stroke, they
are at an increased risk of atrial fibrillation.
AFib is an irregular and rapid heartbeat that
can lead to other heart related conditions.
Researchers out of the University of Pennsylvania found
that the risk of Atrial Fibrillation increased about 3%
for every one inch (2.54cm) increase in height over the average.
The lead author of the study said that
their findings “show that a certain group of
patients—specifically, very tall patients—may benefit
from screening" for signs of atrial fibrillation.
The problem with looking at particular illnesses
and their relationship to height is that they can’t
give you a holistic picture of what’s going on.
We know that being taller gives you an increased
risk of cancer, but we also know that being
shorter gives you an increased risk of heart
disease, and that doesn’t really clear up anything.
One theory suggests that a gene group called FOXO
might be a factor in determining human longevity.
A research article from 2014 by the Honolulu Heart
Program made a connection between nutritional balance
in childhood, the FOXO genes, and height in adulthood.
Basically, the better fed you are
as a baby, the taller you will be.
Knowing this, researchers found that the FOXO gene was less
frequent in taller individuals, which suggested to them
that it could be connected to early childhood development.
So one explanation for the fact that tall people
generally live shorter lives could be that this
FOXO gene is what helps shorter people live longer.
Their theory is that one’s nutritional intake
in infancy determines if it will express itself.
Infants who get enough to eat end up growing
taller in adulthood, but this special
super survival gene doesn’t “turn on”.
However, if an infant isn’t getting enough food
they’ll be a little shorter in adulthood, but
this gene will kick in to help them survive.
Is FOXO a secret gene that makes us live longer?
Maybe! We don’t really know yet!
Science rarely offers us clear cut explanations for things.
For most of human history, we knew that the sun rose
and set, mothers gave birth to children, and the
seasons changed with the year, but we didn’t know why.
Like science communicator Destin Sandlin
said on his fantastic youtube show Smarter
Every Day, “Knowledge is not understanding”.
We have the knowledge that shorter individuals
live longer lives than their taller
counterparts, but we don’t understand why.
It just goes to show that you can have the knowledge of
something, but to understand it, you need to dredge up
all sorts of complicated not-easily-answered questions.
But let’s be honest, the easiest puzzles
are the least satisfying to solve, right?