I want to look at this from two directions.
First, from a measurement perspective. You may hear news headlines about movements in life expectancy. Fluctuations from one year to the next are usually fairly small. But if you look back a few decades, the gains have been huge in several countries.
It may seem counter intuitive, but a lot of that lift over the past few decades has not been a function of life extension at older ages. Instead, longevity will go up, sometimes dramatically, when more little humans survive their first few years.
Second, do your birth circumstances predict your longevity? To what extent? And if they do, is there anything you can do about it?
Grab your marshmallows and graham crackers and let's cozy up to the fire and contemplate longevity!
YEAH BABY!
One of mankind's greatest accomplishment is the gains in life expectancy. No other species on this planet has had this sort of success story. One of the reasons for these gains is that across the glove more kids are surviving their earliest years. Before looking at that awesome fact, let's revisit why having more children survive the first five years translates to higher life expectancy.
Like any statistic, it helps to know what 'life expectancy' actually means.
Bear with me as we do some simple math.
We have a population with two kids. One lived to 10 years old, the other lived to age 50. The life expectancy for this group is "total years lived" divided by "intial population size."
Now, what would happen if the first kid lived to age 20? The life expectancy goes from 30 to 35. Note that our maximum age (50) did not change.
In the case of a population with only two members, gains in age for either member are equally helpful for the population.
Let's now extend the group to ten individuals. Life is really harsh and 9 out of the 10 die at birth, and 1 of them survives to age 50. We end up with a life expectancy of 5:
If the 50 year old is able to make it 10 more year to age 60, the group gets 1 more year of life expectancy.
If we put that 10 year gain on the youngest group, we will get 9 more years of life expectancy.
If we help half of the kids make it past birth, and assume that they will make it to age 50, we will get a 25 year gain in life expectancy. Again, our maximum age is the same, we just have more members getting there.
Bear with me as we do some simple math.
We have a population with two kids. One lived to 10 years old, the other lived to age 50. The life expectancy for this group is "total years lived" divided by "intial population size."
(10+50)/2 = 30 years.
Now, what would happen if the first kid lived to age 20? The life expectancy goes from 30 to 35. Note that our maximum age (50) did not change.
(20+50)/2 = 35 years.
In the case of a population with only two members, gains in age for either member are equally helpful for the population.
Let's now extend the group to ten individuals. Life is really harsh and 9 out of the 10 die at birth, and 1 of them survives to age 50. We end up with a life expectancy of 5:
(0 + 0 + 0 + . . . + 50)/10 = 5 years
If the 50 year old is able to make it 10 more year to age 60, the group gets 1 more year of life expectancy.
If we put that 10 year gain on the youngest group, we will get 9 more years of life expectancy.
(10 + 10 + 10 + . . . + 50)/10 = 14 years. The gain is 14 - 5 = 9 years.
If we help half of the kids make it past birth, and assume that they will make it to age 50, we will get a 25 year gain in life expectancy. Again, our maximum age is the same, we just have more members getting there.
(0 + 0 + 0 + 0 + 0 + 50 + 50 + 50 + 50 + 50)/10 = 30 years
Ok, math is done now.
Here's the bottom line. With longevity, if we get more kids out of infancy and well into childhood, the life expectancy at birth will improve. This effect is larger if we have high childhood rates of death to begin with.
And in fact that is what has occurred across the globe.
And in fact that is what has occurred across the globe.
This animation helps tell the story. The bubbles in the picture below are different countries.
- Red is East Asia and the Pacific
- Orange is Europe and Central Asia,
- Yellow is the Americas
- Green is the Middle East and North Africa,
- Light blue is South Asia
- Dark blue is Sub-Saharan Africa
| From: Business Insider and Gapminder |
What are the driving forces that help explain this shift?
What obstacles are we facing to help keep the trend going?
The leading causes of childhood deaths today include:
Iceland seems to lead the developing world at less than 1 childhood death out of 1,000! Currently, the U.S is around 6 per 1000.
I highly recommend visiting 'Our World in Data' for a more thorough discussion of this issue.
- Improvements in living standards
- Improvements in medical knowledge and care
- Particular treatments for disease
- Access to nutrition
- Clean water and sanitation
What obstacles are we facing to help keep the trend going?
The leading causes of childhood deaths today include:
- Pneumonia as a result of bacterial infection and poor nutrition
- Premature birth
- Diarrhea
Many of these are quite preventable and a little bit of effort goes a long way. Some organizations that address these issues are Assist International, Save the Children, Unicef, the Bill and Melinda Gates Foundation and I'm sure there are many others. Feel free to share any organization you may support.
Iceland seems to lead the developing world at less than 1 childhood death out of 1,000! Currently, the U.S is around 6 per 1000.
I highly recommend visiting 'Our World in Data' for a more thorough discussion of this issue.
For instance, an interesting second order affect of the falling rates of childhood is deaths is that people, in general, start to have less kids.
So we are making progress on helping kids survive their early years. Then what else do we need to think about?
So we are making progress on helping kids survive their early years. Then what else do we need to think about?
Playing The Cards You Are Dealt
Suppose Mr. X is born in an upstate New York hospital, to couple of millionaires who run a fitness empire.
Ms. Z is born in rural India, the seventh kid in her poor family, and she might not see her dad for months.
Who lives longer?
To be fair, it's a bit of a loaded question. In order to really know this, we have to follow a group of people from their origin until death. So you might not have an outcome for several decades. By then any one of the original conditions might not matter anymore!
But let's try to think about this some more. There are several conditions we can look at, and some may be proxies for other things.
What's Your Sign?
Turns out, there seems to be a seasonal effect. A possible reason is that certain seasons encourage different pregnancy experiences: activity, availability of food, etc.
Healthier moms make healthier babies, in general. More on that later.
Birth Order
Middle child, baby of the family or firstborn? Guess who lives longer? First born does. Again this may be part of the health of the mother, because the parents are obviously at their youngest when they have their first kid.
Related to this is familial structure. The number of brothers and sisters you have, or whether your parents stay together, may also impact how long you live. Although these may also be proxies for wealth/poverty.
Born in the U.S.A
Location of birth (might) matter. But this might be one of those items that is really driven by education/income level, access to healthcare and other environmental influences. Generally, across the globe, regions are approaching similar longevity levels.
In the US, longevity by zip code shows that there can be large disparities between neighboring areas. The environmental hazards (mosquitoes, storms, etc.) would be similar, so it points to other elements listed above.
Born this Way
Scientists who study longevity genetics often first will come to a conclusion based on studying animals like worms, mice, or dogs. Not all animal studies cross species, but some do. Tying a gene to longevity is done in one of two ways: correlation (people who live long often have this gene) or studying what the gene actually does. Generally, genes that control your metabolism and stress responses can influence the speed at which you age.
And of course, your gender also plays a role. However, like many of these things, while males and females have different biological processes, as you grow up other things may start to cloud the true natural variation. Things like occupational risks and cultural norms start to influence mortality rates in adult life.
The Baby Mama
As alluded to in a few of the above items, the mother plays a critical role in determining the health and longevity in the child.
While pregnant, the mother's conditions will affect the development of the child. It all matters, from the things she consumes (alcohol, tobacco, nutritious foods, etc.) to the things she does (exercise, strenuous labor).
The birth itself matters, as healthy natural births lead to a better microbiome than cesarean births.
For the newborn, breastfeeding may be a factor as well.
Finally into childhood, nutrition plays a huge role along with the mother-child bond.
No Drama
Finally, early life stress and trauma can create a setback to longevity. There are psychological implications that could extend into adulthood. There can also be epigenetic factors that again influence stress responses and how the body reacts to future drama.
Wealth = Health
Money might not buy happiness, but it may lengthen your life. Wealth translates to better initial conditions: nutrition, sanitation, education, support systems, living conditions and so on. The silver lining here is that at the very bottom end of the wealth spectrum, minor improvements could yield large gains.
Adding it All Up and Looking Ahead
From the above categories, we can see that there are a number of preconditions that will affect your odds of living a long life. But how significant are these things relative what you do in the years that follow?
Unfortunately, the answer isn't totally clear. However, both matter. You can erase any longevity "advantage" you may have been born with by choosing to smoke, eat nothing but donuts, and pursuing a career as a lumberjack.
Furthermore, it may be the case that many of the headwinds one might face at birth get less powerful as time goes on.
Wealth in the world is generally going up and education is as well (distribution is a different question).
Wealth in the world is generally going up and education is as well (distribution is a different question).
Treatments for various genetic disorders may soon be a reality due to the following trends:
- Reductions in the costs of genomic sequencing
- Increasing availability of genetic data across populations
- Prevalence of machine learning and AI algorithms
- Advancements in gene therapies (like CRISPR)
In short, for most of the world, there may be a trend towards a more level playing field at birth, which is great news and something to hope for. There probably won't ever be a complete equal starting point, and it may be that the wealthiest get to take take the most advantage of advancements at first.
Optimistic futurists believe that the first person to live to age 150 has already been born. Extremely optimistic futurists believe that we may be giving birth to a human who live to 300, or possible even escape the upper bounds of age altogether!
Does that seem far fetched? In my next contemplation we will shift focus to the other end of the spectrum and look at what's going on at the end of life.
Until then, enjoy "You Were Born" a song by one of my favorite bands, Cloud Cult.
