Friday, January 12, 2007

A Surprising Secret to a Long Life: Stay in School

This article takes a look at what does and does not impact health. I think it makes a lot of sense to focus on improving health rather than health care. Surprisingly extra money does not lead to better health and genes don't have much impact on longevity but extra education and social isolation do.

The one social factor that researchers agree is consistently linked to longer lives in every country where it has been studied is education. It is more important than race; it obliterates any effects of income. And, health economists say, those factors that are popularly believed to be crucial — money and health insurance, for example, pale in comparison.

Dr. Smith explains: “Giving people more Social Security income, or less for that matter, will not really affect people’s health. It is a good thing to do for other reasons but not for health.”

Instead, Dr. Smith and others say, what may make the biggest difference is keeping young people in school. A few extra years of school is associated with extra years of life and vastly improved health decades later, in old age.

It was 1999 and a Columbia University graduate student, Adriana Lleras-Muney, was casting about for a topic for her doctoral dissertation in economics. She found an idea in a paper published in 1969. Three economists noted the correlation between education and health and gave some advice: If you want to improve health, you will get more return by investing in education than by investing in medical care.

It turned out that life expectancy at age 35 was extended by as much as one and a half years simply by going to school for one extra year.

Now, others papers have appeared, examining the effects of changed laws on compulsory education in Sweden, Denmark, England and Wales. In every country, compelling children to spend a longer time in school led to better health.
Amazing that education gives a greater return on investment to improve health than medical care.

Why is this?
Dr. Lleras-Muney and others point to one plausible explanation — as a group, less educated people are less able to plan for the future and to delay gratification. If true, that may, for example, explain the differences in smoking rates between more educated people and less educated ones.

He deplores the dictums to live in the moment or to live for today. That advice, Dr. Smith says, is “the worst thing for your health.”
Interesting. This goes along with the Marshmallow Experiment and the idea that skills like delayed gratification should be taught in schools if they aren't taught at home.

What else besides education impacts health?
The risks of being socially isolated are “phenomenal,” Dr. Berkman says, associated with twofold to fivefold increases in mortality rates.

Dr. Smith also asked whether getting richer made people healthier, an effect that could translate into a longer life. It does not, he concluded after studying the large increases in income during the stock market surge of the 1990s.

Health and nutrition early in life, even prenatally, can affect health in middle and old age and can affect how long people live.

For the most part, genes have little effect on life spans. Controlling heart disease risk factors, like smoking, cholesterol, blood pressure and diabetes, pays off in a more vigorous old age and a longer life.
I would like to understand more about how they came to the conclusion that genes have little impact on life spans. This is counter to other research I have heard of.

While health and wealth are correlated, the direction goes from health to wealth and not the other way around.
If someone developed cancer, heart disease or lung disease — which will affect about a fifth of people aged 51 to 61 over the next eight years — the household’s income declined by an average of more than $37,000. And its assets — its wealth — fell by $49,000 over the ensuing eight years, even though out-of-pocket medical expenses were just $4,000.
I would like to see more research into "health assets" or some way of measuring the aggregate health of Americans in comparison to the total wealth in stocks, bonds and real estate. Seems like there are lots of investments in health that would give a higher return on investment, but without being able to quantify it, it is hard to compare that with investing in stocks. If you have a chance to be an investment banker which allows you to accumulate a lot of wealth but also leads to stress and decreased health, it would be good to be able to quantify that loss of health wealth. Or all the soldiers that are being wounded in Iraq. They are obviously losing health assets, but how much? Or pollution that is being spewed by coal power plants. How much are these decreasing the health assets of people living around them. From the analysis here, a 50 yr old that will get one of these diseases has $50,000 less in wealth than a health individual, but this wouldn't show up on any financial wealth estimates of the two people.

Some really interesting ideas in this article, and there are also a couple of graphs on education and health statistics.

via NY Times


crush41 said...

I'd wager IQ trumps years of education, although the latter certainly proxies for the former. Nationally, life expectancy correlates with IQ at an astounding .85 (more than doctors per capita, purchasing power parity, or any other variable I looked at). The reasons are probably similar to what one source quoted said--the ability to delay gratification and think long-term.

crush41 said...

Also, the dismissal of genes as a cause of longevity is ridiculous and not at all quantified or even qualified in the article. While the HapMap is making great progress, scientific knowledge of genes and how they affect health is an arena in its infancy.

al fin said...

I agree that IQ is a better, more reasonable correlation with long life than years of education. Also, genetics probably moderates both IQ and EQ (emotional intelligence) traits such as ability to delay gratification and think long-term.

Character traits can be taught, to a degree, but predisposition to personality and character traits is also genetic.

There is a powerful trend in politically correct academia to deny genetic influence. It tends to make some researchers appear less than honest.

Fat Knowledge said...


What % of IQ is genetic and what % is influenced by environment?

You might be right about IQ trumping education, I don't know.

If you are making the case that the genetic part of IQ and other genes are the more important factor in determining longevity than education, you might also be correct. But, the question I find interesting is if you take the genetics as a given, what is the best way to improve the health of people? Is it better health care, better education, better pre-natal and infant care, or something else?

I agree that they didn't really say what they were talking about in terms of genes. One way that they might have been looking at it is comparing life expectancy in the US in 1800 with 2000. It has gone up a ton but it is doubtful that genes had much to do with it. Also compare countries it is hard to believe that the difference in life span between Japan, Scandinavian countries, the US and African countries is primarily due to genes.

But, comparing the lifespan of 2 Americans in 2007 I would think individual genetic differences could explain quite a bit of the difference in lifespans.


I don't know to what extent researcher bias against genetic influence affected the results. My guess is that as economists the bias they had was toward easy to gather data and getting genetic data would be tough.

al fin said...

Have you read about the recent "long life gene" that also confers mental clarity into old age? It was found in Ashkenazi Jews--the same population with the highest mean IQ so far.

Genetic correlation of genes with IQ is well above 50%. And most of the environmental influence on IQ is the "environment of the womb" and other unshared environmental factors. That is why non-identical twins IQ has so much less correlation than identical twin IQ.

Two fetuses in the same womb do not share the exact same environment. If that is true, it is easy to understand the concept of non-shared environment out of the womb.

In other words factors that are not shared cannot account for correlation in IQ, health, or anything else.

crush41 said...


Professor Flynn (of the eponymous "Flynn effect"), who is among the skeptics of genetic determinism, puts it at 75%-genetic, 25% environmental/other. That means there is a lot of room for environmental or epigenetic variation (although what is usually taken for granted as being environmental may be effectively random and not easily controllable). Others like Lynn put it higher, upwards of 80% genetic.

As far as what to do--the bottom appears to have much greater potential to be raised. Nutritional supplements would go a long way in sub-Saharan Africa for example, where cretinism is endemic.

Other things--incentize or make mandatory breast-feeding, make it a felony to smoke, drink, or consume other illicit drugs while pregnant (unfortunately the NARAL crowd will never go for this, despite the enormous benefit it would have on the lower classes' offspring).

And then there is that nasty little thing known as 'eugenics'. Sure, we use it on crops and livestock, medicine and pets (to great effect, all), but since some irrationally racist dictator is associated with it, it is forever to remain on the memory heap of ugly history (not really, as some 91% of Chinese scientists favor the use of eugenics for the good of society--the Occident is dying/falling behind in more ways than one. And one of my favorite charities, Project Prevention, is voluntarily--and I wouldn't support involuntarily--eugenic).

Fat Knowledge said...


I wasn't aware of the "long life gene", thanks.


Thanks for the breakdown of genetics vs. environment on IQ. I agree anything we can do on the environmental side to raise intelligence of people would be a good thing.

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