Why is everyone else getting taller?
A paper (free full text) in this month’s Social Science Quarterly points out an interesting but not entirely unexpected phenomenon: people in the rest of the world are growing taller than those of us in the United States.
It seems remarkable that this could happen because over the past couple of centuries people in the United States were significantly taller than their European counterparts. Suddenly, starting in the 1950s, people in the US quit growing. They didn’t get shorter; they simply quit growing larger. For years, just as there has been an improvement in longevity in this country, there has been an ever increasing increase in average height. Then, in about 1950 it stopped. People born in the years 1955-1974 for the first time were no taller than those born the years previous to that. People born in the rest of the Western world during those years raced past us and now surpass in average height those Americans born between 1955 and 1974.
What has happened? Why the steady gains in stature for two centuries, then a reversal? Why does the rest of the world continue to grow?
Good questions all. The answers, I suppose, depend upon whom you ask.
If you ask the researchers that wrote this paper, you’ll get one answer. If you ask me, you’ll get another.
The people who wrote the paper are sociologists. I’m a physician grounded in biochemistry and physiology. Let’s see how our answers differ.
First, though, just to give you an idea so that you can start thinking ahead…remember back when you were in school and all the people you knew were separating out into their different majors. Some went into engineering, others into science, others went into history, literature or the arts, and some went into sociology. Remember the ones who went into sociology? Well, those are the people who became sociologists, so that explains a lot.
After going through all the statistics to show that there really is a growing discrepancy between the average heights of Americans and the average heights of Europeans – which I have no problem accepting – the authors speculate on the cause of this difference.
They first make a nod toward nutrition:
Why U.S. heights declined in relative terms remains a conundrum, a topic for future research, but even at this stage of our knowledge we can conjecture that there are differences in the diet of U.S. and European children that could affect human growth. For example, U.S. children consume more meals prepared outside the home, more fast food rich in fat, high in energy density, and low in essential micronutrients, than do European children.
Then they launch into what I consider lunacy:
Moreover, consideration of the differences in the socioeconomic institutions of Europe and the United States might help in at least beginning to resolve this paradox. Without claiming to propose a comprehensive answer to this quandary, we propose the hypothesis that there are several crucial differences between the western and northern European welfare states and the more market-oriented economy of the United States that might well shed further insights into this paradox. This includes greater socioeconomic inequality and more extensive poverty in the United States. European welfare states provide a more comprehensive social safety net, including universal health-care coverage, while the share of those who have no health insurance in the United States is about 15 percent of the population. Is it possible that the western European welfare states are able to provide better healthcare to children and youth than the more market-oriented U.S. one? Or is there something about the quality of healthcare that is responsible for these results?
Jesus wept.
It should be real easy to determine whether the above sociological jibberish holds any merit: simply compare wealthy Americans (all of whom presumably have decent healthcare) to wealthy Europeans and poor Americans (who presumably have bad healthcare) to poor Europeans (who supposedly have the same health care as the wealthy). If the wealthy Americans and Europeans are the same height and the poor Americans are shorter than the poor Europeans, then we could maybe make a case for a difference in health care. If both rich and poor Europeans are taller than their American counterparts, then it’s tough to make a case for a healthcare difference causing the problem.
The authors do look at this. And what do they find?
The lagging U.S. height performance is not caused by a long left tail in the height distribution. Heights are normally distributed and the whole U.S. height distribution is shifted to the left. In other words, rich Americans are shorter than rich western Europeans and poor white Americans are shorter than poor western Europeans.
Case closed. Or as Samuel Johnson would have said, “There’s an end on’t.” It ain’t a difference in the healthcare system.
So, what is it?
I would say it is the massive amounts of soft drinks that American kids drink compared to their European counterparts. That huge upswing in soft drink consumption in the U.S. started post WWII and has increased since.
How would soft drinks make us shorter?
It’s a little complex, but let’s tackle the physiology.
First, puberty and growth are stimulated by sex hormones and IGF-1 (insulin-like Growth Factor). These hormones are in two forms: the free form and the bound form. The free form is when the hormone is off doing its hormone-y thing. The bound form is when the hormone is bound to its binding globulin. Both hormones circulate in the blood in both ways: bound and free. When you get a blood test, it measures the total, i.e., both free and bound. If you want to see what the actual active hormone is doing, you’ve got to get a Free Testosterone or a Free IGf-1.
The binding globulins for these hormones are made in the liver. If the liver cranks out a lot of binding globulin, then a lot of the hormone will be bound and not be active. If the liver does the opposite and produces little binding hormone, then the amount of hormone bound will be less and there will be more active hormone out doing its thing.
Elevated levels of insulin drive the liver to make LESS binding globulin, which means that there will be MORE of the free and, therefore, active hormone available. More IGF-1 leads to acne, nearsightedness, and an early growth spurt. More free sex hormone leads to an earlier puberty and closure of the growth plates. (the growth plates are at the ends of the bones, and when the growth plates close, the bone quits growing in length. When long bones stop growing, you stop getting taller.)
What make the levels of insulin go up? We all know the answer: carbs. Especially refined carbs. Especially sugar. Even worse is fructose because fructose adversely affects the liver without raising insulin levels.
What are soft drinks? Sugar water. Sugar water now made with high-fructose corn syrup (HFCS). Both sugar and HFCS contain glucose which raises insulin and fructose which makes the insulin even more harmful to the liver and enhances the liver’s insulin resistance.
An insulin resistant liver makes less binding globulin, less binding globulin allows more free hormone, more free hormone hastens puberty and stops growth. Voila! A much more sensible explanation than that concocted by our sociologist friends in the above paper. And one grounded in science, not a we-should-have-socialized-medicine twisting of the facts.
There is another viewpoint on this. When I read this paper, I emailed by bud Loren Cordain to see what he thought of it. He has a different theory than I do on the actual physiological cause, but, as he sees it, the underlying problem is the same.
Here is an excerpt from his email to me (reproduced with his permission):
After attending the Harvard conference on milk drinking & sitting through the Brit’s presentation of a famous longitudinal trial on milk drinking and stature conducted in the 1930′s and resurrected in the present with still living members, my feelings are that increased milk consumption probably is the most important dietary determinant of adult stature. The two underlying mechanisms: BTC in milk binds human luminal gut EGF-R and ends up in circulation and thereby binds 3 of the 6 EGF-R dimers in chondrocytes, thereby promoting skeletal growth during development; secondly the (protein + lactose) in milk facilitates insulin resistance which increases IGF-1 and further adds to milk’s growth promotional effects during adolescence. The probable reason Europeans are surpassing Americans in stature is because they continue to have high milk consumption while US teens have replaced milk with soft drinks. BTC + lactose is more powerful than sucrose alone in promoting increased stature.
I like my rationale better, but we are both in agreement that the root cause of the decrease in stature is the increased consumption of soft drinks during the childhood and teenage years.
They’re poison. Don’t let your kids drink them.
Dr. MRE,
Does height really matter? Is it a very good indicator of overall health and/or longevity?
-Z
Hi Zen–
A number of studies have shown that both economic well being and longevity are a function of height. Plus, it’s a marker for good nutrition.
Cheers–
MRE
Another thing I’ve noticed (at least here in Scandinavia and France as well) is that men’s hands seem to be getting smaller. Young men today (20s) often seem to have small hands compared to their fathers’ and grandfathers’ generation, even if they’re taller. It’s almost as if we’ve undergone a super-fast adaption to an environment in which male hands are used mainly for keyboard punching and text messaging.
Any theories about this? Could environmental xenestrogens play a role?
Hi Magz–
I haven’t a clue. This is the first time I’ve heard of it or even thought about it.
Cheers–
MRE
I love your blog! Thanks so much for sharing it!
I just read about a possible new diabetes drug which will supposedly prevent diabetes:
http://www.diabetesincontrol.com/results.php?storyarticle=4888
The rationale that is put forth for why to create such a drug was this:
“[... a] gene controls a lipid-binding protein called aP2 that sticks to fats in the blood and escorts them to different places in the body where they can cause trouble.”
“When people eat fatty foods, these aP2 proteins trigger a chain of inflammatory responses, he said. They can reduce sensitivity to the sugar-lowering effects of the hormone insulin — raising the risk of diabetes — and encourage plaque formation in arteries — raising the risk of heart attack.”
“Then comes the question, ‘Since we cannot change the genes of people, can we do this trick with a chemical?’”
I was wondering what your thoughts might be about this line of reasoning. Everything I’ve learned from you and other low carb doctors is that fats alone aren’t bad, fats in that presence of carbohydrate often are.
So we don’t need a drug to deal with the inflammatory effects of fat alone, we need to recognize that it is fat in the presence of carbohydrate which causes the problem, would that be correct?
Hi Karen–
That would be correct. I read the article you linked and I take exception to the statement that follows:
I beg to differ. We don’t ‘know’ that it works exactly the same in humans.
The idea of the inflammatory basis of fat is interesting. I plan a post on it soon.
Cheers–
MRE
Just a quick thought. I agree that Sociology is a suspect discipline these days ( or any days ) but Sociobiology is an absolutely fascinating and very promising field, IMNSHO.
John
Agreed.
MRE
I have some alternate culprits…
1- Temperature. American air conditioning technology is number one in the world. It certainly beats any AC available in Europe. The children needlessly exposed to arctic summers have had their growth stunted due to an abbreviated growing season. It’s the reverse of hot house flowers.
2- Temperature, redux. Sure, Americans drink a lot of coke. But it’s not the coke. It’s what’s in the coke. Ice. Drinking these frosty beverages (I saw many gourmet granitas in Italy, but no cheap slushies) has chilled the metabolisms of America’s youth, resulting in a shorter and ever widening population.
3- Obesity. Since we’re so much fatter, gravity weighs harder on our youth than on European youth. We could catch up if only Europeans would embrace Supersizing.
4- The Government. Clearly, it’s not interested in having a tall population, otherwise we’d be a nation of Yao Mings. I cannot believe that this isn’t a spending priority.
5- Pharmaceutical companies. Clearly, our private sector has missed an opportunity. Who wouldn’t put their kids on Talliva, the drug that guarantees Euro style height.
6- Michael Moore. Everything is his fault anyway.
7- The government. Actually, anything that isn’t MM’s fault is the government. And they’re so backwards, they get mentioned twice.
8- Movies, TV, rap music, rock music and video games. Anything wrong with American kids since the 70′s could be laid at the feet of the entertainment industry. All kidding aside, I bet you could make an argument about sedentary kids and growth hormone.
9- Gas prices. On my recent trip to Italy, I marveled at my Italian friend about the low gas prices. I think it was, after currency conversion, about 10-15% cheaper than what we pay in VA. My friend reminded me that they buy liters, not gallons. If you think a $3 gallon of gas is walking incentive enough, try a $10 gallon on.
10- Minivans. I saw maybe three in Europe. So, kids ride in smaller cars (when they ride at all) with crappy AC (when they have AC at all) with a smaller coke (if they drink it) that has no ice.
11- Trickle Down Economics. Without real charity, our underclasses are starved of nutrients and health care while our rich people are weighed down by their money. Neither class grows to it’s full potential.
I crack me up.
I have the real answer, all kidding aside. It’s posture. If we have a real crisis in the US, it’s a posture problem. Too many 6’2″ men are slumped over badly designed desks on bad chairs, with junky monitors, causing the development of lordosis and kyphosis and robbing them of crucial inches in the height war with goofy Europe. Meanwhile, those crafty Europeans, with their socialistic tendencies, give their office drones ergonomic chairs, adjustable desks and workable monitor stands, allowing them to stand to their full glory. Sadly, our current government doesn’t even believe in repetitive stress disorders or the science of ergonomics. So, the insanity will continue and we will lag behind europe in the crucial height race.
PS- Really. I cannot believe that these people got this funded, much less published. Who cares? Europeans have some inches on us. Big deal. We have privatized health care, a minimal safety net, the best military, the biggest trade deficit, etc, etc. We’re number one (in everything but height. And life expectancy. And education. And health care outcomes. And infant mortality. And poverty rates. And employment rates. etc).
Hmmm. Interesting commentary.
Cheers–
MRE
I was in Holland for work about 5 years ago and was surprised to note that the Dutch drink milk with nearly every meal. It’s their beverage of choice. I don’t know if this has any correlation with them being the tallest people.
Ger
“Jesus wept” indeed. On the heels of reading your post yesterday, I ran across Jane Brody’s column in the paper entitled “Obesity Begins at Home.” Among her suggestions for how to feed your children more healthily is this:
“Frozen fruit ices, which have no fat, are another good choice in hot weather.I worry far less about the sugar content than the amount of fat in a frozen desert.
Drinks, too, can be a source of pointless calories. Stick to pure fruit juices, water, low-fat or nonfat milk. Avoid fruit-like beverages labled ‘drink,’ because that means most of it is sugar water, not fruit juice. And there is no justification for giving children sodas, with or without sugar.”
So, in other words, you can give your kids all the sugar you want as long as it’s fruit. When did fruit juice become a health beverage to be drunk by the gallon? Am I the only one who remembers when fruit juice was served in a tiny glass made expressly for that purpose? No wonder kids are getting shorter.
I’m the short-cake of my family at 5″4.” My younger brother and sister are 6’6″ and 5’11″ respectively. But there are compensations. I’m the only one of us three who can travel comfortably on any size airplane in any size seat without having to stick my legs in the aisle.
Hi Esther–
There is very little difference between soft drinks and juice. A few vitamins in the juice, but about the same amount of sugar. But folks seem to think it’s okay because it’s juice.
Cheers–
MRE
Well, my daughter drinks soda. (I know, I’m working on it.) She also drinks tea. She is 5’5″ at 12 years old. However, many in my family are tall. We have Dutch ancestry, so perhaps it’s genetics? I am 5’7″. Interestingly, I had grown two inches (from 5’5″ after I was 30 and had been put on prednisone for hives {I’ve had problems with my weight since the same time}) I have an uncle, born here in Fla who is 6’4″. I have a cousin (male) who is 6’5″. Of my close (geographic) female cousins, I am now one of the shortest. They are 5’10″ and 5’11″. My grandmother is 5’0″. (?!?) In my daughter’s class, there are only three of them who are tall like this.
My daughter has always been off the chart in size. Though her height/weight ratio was good. I think they were afraid something was wrong with her at one point. She was breastfed. Since she has started school, she has gained weight. So, we are working on that. She gets the salad shakers a lot, so I wasn’t happy to read about an experiment supposedly done with the salad dressing. =(.
Oh, couple more thoughts on the missing height.
1- It’s the metric system. And our schools. The scientists failed to convert inches to meters correctly, and short changed Americans.
2- It’s the school system. Not enough gym. And teaching to tests doesn’t encourage students to stretch themselves properly, inhibiting not only their mental growth, but their physical as well.
I also said, “Europeans have some inches on us.” I should have said, “Europeans have some centimeters on us.” Down with English Weights & Measures. Long Live the Metric System, a system that actually makes sense, unless it’s what’s preventing Europe from developing sufficiently cool air conditioning (once they solve this mystery, they’ll be back down to size in no time).
Hi Max–
You may have some argument on the metric vs English system.
Cheers–
MRE
To Sarah (or anyone who knows): What is the IF dietary plan? I have never heard of it. Thanks.
Hi Erik–
Type ‘intermittent fasting’ into the search function on the front page of this blog, and you will learn everything you need to know about the IF dietary plan.
Cheers–
MRE
On behalf of sociologists everywhere: Hey!
Let me say first that I don’t dispute that diet and nutrition are probably more immediate causes of differences in height than social policy. The study would have been more illuminating if the authors could have included dietary factors.
However, let me make a couple points:
1. Social Science Quarterly is not exactly the most prestigious journal in Sociology. This story was picked up by news outlets because it’s a “fun” sound byte. Reading the article (the SSQ article, not the NYT article), left me with a number of questions as well.
2. No one is denying that nutrition is related to height. But it would also be grossly ignorant to think that social factors don’t affect nutrition (and I don’t just mean education and income, which is what the authors controlled for). The disconnect here is that social scientists are interested in social factors, and doctors are interested in physiological factors.
I don’t think any sane social scientist would say that social policy has a larger effect on height than nutrition. It’s just that we’re social scientists, and we’re more interested in the impact of social variables. It’s what we study. Any idiot can say, it’s obviously diet and nutrition that affect height. A doctor might be interested in specifically what kinds of diets are resulting in vertical growth. But a social scientist is curious about which social factors affect what diet people follow and why. (Which, admittedly, the authors of this study did not do a fantastic job of, but nevertheless.)
Obviously, some synthesis of the two is needed to get a more accurate depiction of what’s causing height differences, but it’s not always easy to cross disciplinary boundaries. Therefore, social scientists do work and come to conclusions that doctors think are ridiculous, and sometimes doctors do research and make policy recommendations that social scientists find absurd because they are unrealistic or are targeting irrelevant social factors.
3. I’m disappointed that you would hold up this study as evidence that all sociologists are stupid. There are a great many people in your field that you (and I) disagree with about nutrition, but I don’t look at doctors who say that 100g of protein a day is unhealthy and think, “Man, all doctors are stupid.”
As a graduate student (and TA) in Sociology, I can verify firsthand that we get much of the dregs of the undergraduates. But the dregs are certainly not the people who go into PhD programs and do research like this. Nor is it only Sociology undergrads who go into sociological research. I myself have a bachelor’s degree in Computer Science from an Ivy League university and worked several years in the industry before joining the Sociology PhD program I’m in now.
4. I think you are overstating the degree to which these sociologists are saying that welfare states creates tall people. They are merely suggesting it might be one of the causal factors. Like all “good” social scientists, they’ve even phrased it as a question (as you’ve quoted above):
“Is it possible that the western European welfare states are able to provide better healthcare to children and youth than the more market-oriented U.S. one? Or is there something about the quality of healthcare that is responsible for these results?”
They admit in their concluding paragraph that it’s just conjecture since their study is more descriptive. Their study is attempting to answer the question, what are the differences in height between Americans and Europeans over time controlling for education and income? They are not trying answer the question, what is the impact of social policy on height? If they had tried to answer that question, they would have looked at very different data.
Their consideration of these questions is an opening point for future research and for discussion, which I am glad to see in abundance in your blog and commenters. So consider this diatribe an addition to the discussion.
Hi syl–
Thanks for the sociologist’s perspective. But, just for the record, I did not write that sociologists are stupid. I didn’t even imply it. I carefully crafted my sentences to not be judgmental, but to allow the readers’ opinions of sociology majors to lead them to their own judgments.
My take on the study is that the authors merely threw a bone at the idea that nutrition could be causal, then spent pages looking at all the social variables as the root cause. Some nutritional change should be the most obvious driving factor, and only after nutrition is eliminated as a cause by intensive analysis (which it wasn’t) should other much less likely factors be considered.
I’m glad you’ve joined the debate.
Cheers–
MRE
My understanding, from friends that have lived abroad, that Americans eat more meat that is grain fed, loaded with drugs, etc, while Europeans eat more grass fed, more naturally raised meat.
This could also be a contributing factor?
Hi Cindy–
If anything, the hormone-loaded meats and dairy products that we get in the US would make us taller. I don’t think that’s what it is that’s making them continue to increase in height while we stay the same.
Best–
MRE
I’m thinking it might just simply boil down to ethnic (genetic) differences. The fact is america is rapidly become an ethnically diverse nation… and our “european americans” are not as european (genetically) as they were decades past. Even if they did control for ethnicity… it is not necessarily true that those who self-identify as caucasians to be of homogenous, european lineage.
For example, I consider myself white, caucasian, european american etc but my grandmother is from north africa.
And, I’m quite certain many other “european americans” are part hispanic, asian, etc.
This is less of a factor in europe; the genetic height potential of an englishman is similar to an irishman or someone from wales etc.
However the genetic height potential of someone of european ancestry is MUCH different than someone of pure mexican, latin american ancestry.
Now I’m not saying nutrition or environment doesn’t play a role…
… but do you know why why are we shorter?
Probably because we’ve got a bigger family now, with different genes.
Most of this was corrected for in the study. Read the whole thing to see what I mean.
Cheers–
MRE
Could it be that the Americans have reached the maximum potential growth as dictated by the environment and the Europeans are just catching up?
Who knows what the maximum potential growth as dictated by the environment are? I certainly don’t.
This is purely anecdotal but I find it interesting.
I was a late bloomer…wasn’t allowed much soda growing up (my parent’s were ahead of their time) but I was a big milk drinker. Still am though I know it’s not making me any skinnier. Anyway, while all of my male classmates were getting hairier, bigger, and stronger I was always lagging behind. My voice change came later in high school and I would say it wasn’t until my early to mid twenties that I finally filled out.
I don’t see those people much anymore, but on the rare occasion that I do, I’m always surprised to find how small and frankly sickly looking they are. Sure there could be any number of factors affecting these people, and it’s not across the board, but interesting none the less.
On another note, I lived in the Netherlands for a few years and I can tell you that they are a) big dairy consumers, and b) quite tall. I’m almost 6’3″ and I was barely average out there. I’m used to seeing over the tops of people’s heads, but not in that country. You could easily tell what one’s ancestry was by their stature. Typically the Turks and Moroccans who immigrated there were almost comically short compared to their Dutch countrymen.
Nonetheless, in my ten years living in Europe, I found that sodas became more and more prevalent. Early on I noticed that when you asked for a soda in a restaurant you would get it in a very small glass, and typically it would be warm. Your choice was pretty much Coke or Diet Coke. Most people had wine or beer with their meals. Even in McDonalds the cups they gave you were half the size of American servings and you had to pay for refills. Eventually though (and honestly I didn’t even notice it while I was there) the soda servings became larger and so did the flavor choices. A few years before I left, they started putting the soda fountains in the front and refills became free at most fast food joints.
You’ve spent some time over in Europe haven’t you Doctor? Any observations from your perspective?
Michael
Hi Michael–
Yes, I’ve spent some time there. In fact, I’m going back in a few days for three weeks.
I’ve noticed pretty much the same thing you have: the McDonald’s-ization of Europe. I don’t ever, ever drink soft drinks, so I haven’t really paid much attention to the evolution of the soft drink sizes there. I will take a look at it when I’m there, however. I do know that most of the McDonald’s food in Europe is much, much better than what they serve here. There are all kinds of good coffee there (espresso drinks, mainly), whereas the coffee here is pretty wretched.
I’ll report during my upcoming trip.
Cheers–
MRE
As a kid I ate tons of both sucrose and HFCS. Am 5’8″ but I’ve been eating eggs every day for 15 years so my eyesight, at 40, is actually improving. I’ve noticed that these days, girls seem to be entering puberty earlier and boys are doing so later than when I was a kid. What are we doing to our future generations?
I seem to recall looking into this about 2 years ago when this first came out and I was able to attribute it to a the massive influx of hispanic immigrants with just a cursory glance. This is just more truth that science can be used to further a political agenda.
The paper addresses this issue and corrects for it.
Average heights around the world. The US doesn’t exactly jump out at you if you look at the averages.
Interesting chart. Thanks for posting. You’re right, the U.S. doesn’t jump out at you.
i am 20 years old,hieght is 5’6″.my ancestry is bangladesh,i often confused with my hieght,so, how can i get taller now after my puberty?please know me details to keep me free from such a mental thoughts.
It’s pretty much impossible to gain additional height after puberty, but it does happen on occasion. As far as making it happen, I don’t have a clue. I would make sure I ate plenty of protein because new bone and lean tissue are primarily protein and it’s hard to grow without it.
MRE
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