Poverty Is Stamped Into DNA in Childhood — And Stays There

A poorer upbringing increases people’s susceptibility to colds later in life, something they can’t shake even if they climb the socioeconomic ladder.

National Journal
Brian Resnick
Add to Briefcase
See more stories about...
Brian Resnick
Nov. 5, 2013, 9:04 a.m.

Poverty, it turns out, is etched in­to our DNA.

“For each de­crease of one year in par­ent­al home own­er­ship, the par­ti­cipants’ odds of de­vel­op­ing a cold in­creased by ap­prox­im­ately 9 per­cent.”

That’s not a meta­phor­ic­al state­ment. Grow­ing up poor leaves a per­man­ent mark on our per­man­ent ge­net­ic code, ac­cord­ing to new re­search.

So­cioeco­nom­ic status dur­ing child­hood cor­rel­ates with short­er sec­tions of DNA, known as te­lomeres, later in life, ex­plains a study pub­lished in the Novem­ber is­sue of the journ­al Brain, Be­ha­vi­or, and Im­munity. Te­lomeres are the caps to a strand of DNA and, like a case cov­er­ing an ex­tern­al hard drive, they pro­tect the in­tern­al data from cor­ro­sion. Without get­ting too deep in­to the sci­ence, the length of the te­lomere is a rough in­dic­at­or of the age and health of a hu­man cell. Every time a cell splits in­to two, the te­lomere is slightly shortened. So DNA de­grades as it di­vides. It’s a com­pon­ent of hu­man aging. It’s also the reas­on why cloned an­im­als like Dolly the sheep don’t live as long as the ori­gin­als — you make a baby an­im­al with old DNA, and it ages faster.

More broadly, the te­lomere “is a mark­er of the func­tion­al­ity of cer­tain im­mune cells,” lead re­search­er Shel­don Co­hen says. “The short­er these te­lomeres, the less func­tion­al these im­mune cells are. ” And some­how poverty is in­scrib­ing it­self on the code of man­kind.

Co­hen’s study found that for each year a per­son spent liv­ing in a home their par­ents didn’t own (a rough, yet re­l­at­ively re­li­able in­dic­at­or of so­cioeco­nom­ic status), the te­lomere length de­creased by 5 per­cent.

And what can be seen un­der the mi­cro­scope is re­flec­ted in daily life. In the study, par­ti­cipants were asked to take a dose of a cold vir­us (ap­par­ently, to get people to agree to get sick for sci­ence, you have to of­fer them $1,000 for their ef­forts). Those who in­dic­ated a lower so­cioeco­nom­ic status as a child were more likely to be in­fec­ted by the vir­us and show symp­toms. “For each de­crease of one year in par­ent­al home own­er­ship, the par­ti­cipants’ odds of de­vel­op­ing a cold in­creased by ap­prox­im­ately 9 per­cent,” the study con­cluded.

Co­hen ex­plains that in re­search re­gard­ing cold out­comes, sci­ent­ists must meas­ure wheth­er a per­son was in­fec­ted by the dis­ease in the first place, and then meas­ure that per­son’s im­mune re­sponse to the dis­ease. It’s rare for both sys­tems to be af­fected by the same vari­able (in this case, eco­nom­ic status), Co­hen says. But that’s what is hap­pen­ing here.

“And we vir­tu­ally nev­er find that,” Co­hen says.

Co­hen says the re­search hasn’t found any­thing more spe­cif­ic than so­cioeco­nom­ic status dur­ing child­hood to cor­rel­ate with these health out­comes. That is, he and his team tried to con­trol for factors like di­vorce, home sta­bil­ity, the like­li­hood of people of low so­cioeco­nom­ic status smoking or drink­ing later in life, body mass in­dex, and so on. No oth­er vari­able cor­rel­ated with de­creased te­lomere length or cold out­comes.

There are many ways poverty could af­fect the hu­man body — lim­ited ac­cess to health care, a more stress­ful home en­vir­on­ment, a more vi­ol­ent neigh­bor­hood, and poorer nu­tri­tion can all lead to poor health out­comes. “Whatever it is,” Co­hen says of the ex­act mech­an­ism, “it is hav­ing a big ef­fect and it is hav­ing a broad ef­fect on the bio­lo­gic­al sys­tem.” And im­prov­ing someone’s place­ment on the so­cioeco­nom­ic lad­der would not re­verse the changes chil­dren low on the rungs ex­per­i­enced while grow­ing up. The ef­fects held no mat­ter how well-off people be­came in adult­hood.

A 2009 study from the Na­tion­al In­sti­tutes of Health found that psy­cho­lo­gic­al stress and trauma in youth can trans­late to lower te­lomere length later on. “Both emo­tion­al neg­lect and phys­ic­al neg­lect were linked to short­er te­lomeres,” the pa­per con­cluded, “thus it is pos­sible that in ad­di­tion to the psy­cho­lo­gic­al ef­fects of stress, phys­ic­al stressors such as in­ad­equate nu­tri­tion or ill­ness con­trib­uted to the find­ings.”

If all this seems kind of bleak — that poor chil­dren have a bio­lo­gic­al in­equal­ity etched in­to their cells that they can’t get rid of — well, it is — for now. Co­hen calls the data pre­lim­in­ary, and his re­search field will work in the fu­ture to de­term­ine which vari­ables, if any, vari­able can in­ter­vene in the pro­cess. (Oth­er re­search­ers work­ing on this ques­tion have found in­con­clus­ive evid­ence that so­cioeco­nom­ic status de­creased te­lomere length — though that study didn’t use par­ent­al home own­er­ship as its self-se­lect­ing vari­able.)

While DNA provides the frame­work to our lives, our ex­per­i­ences can dic­tate how that frame fills in. Take lan­guage learn­ing as a sim­il­ar concept. There’s the oft-re­por­ted “30 mil­lion word gap” study, which found that chil­dren in wealth­i­er homes know hun­dreds more words than chil­dren grow­ing up in fam­il­ies that re­ceive wel­fare be­ne­fits. This dis­con­nect causes a gap in lan­guage and learn­ing de­vel­op­ment that widens fur­ther when chil­dren start school.

The lan­guage ac­quis­i­tion is a dif­fer­ent pro­cess, but it tells a sim­il­ar story about the im­pact of en­vir­on­ment.

Co­hen sums it up: “Tra­ject­or­ies are set in child­hood and at least are not eas­ily sus­cept­ible for change.”

What We're Following See More »
REPEATS CONTROVERSIAL CLAIM
Trump: Clinton “Doesn’t Have The Stamina” to be President
2 hours ago
DEBATE UPDATE

At the end of the debate, moderator Lester Holt asked Donald Trump if he stands by his statement that Hillary Clinton didn't have the look of a president. Trump responded by saying Holt misquoted him, instead saying that Clinton "doesn't have the stamina." Clinton responded by saying that when Trump visits 112 countries as secretary of state, he can talk to her about stamina.

WIDELY DEBUNKED CLAIM
Trump: Clinton Camp Started Birtherism
3 hours ago
DEBATE UPDATE

Donald Trump, when pressed by Lester Holt on why he finally admitted that President Obama was born in America, repeated his widely debunked claim that it was started by Hillary Clinton.

“AFRICAN AMERICANS” ARE “LIVING IN HELL”
Conversation Shifts to Race
3 hours ago
DEBATE UPDATE

Hillary Clinton went point by point on how race can so often determine the treatment that people receive, mentioning recent shootings in Tulsa and Charlotte, calling for restored trust between communities and police, and demanding criminal justice reform. Trump responded by calling for law and order and touting his endorsements from police unions. He then said that “African Americans are living in hell,” saying they are just walking down the street and getting “shot ... being decimated by crime."

JUST AS CLINTON INVITES VIEWERS TO VISIT HER SITE
During Debate, Trump Site Appears to Be Down
3 hours ago
THE LATEST

Just as Hillary Clinton was inviting debate viewers to visit her site for real-time fact checking, there appeared to be a problem with Donald Trump's own campaign website. For about a 15-minute period, a blank page or an error message appeared when we tried to load the Trump site.

INTERRUPTS CLINTON MULTIPLE TIMES
Trump Comes Out Swinging
4 hours ago
DEBATE UPDATE

Donald Trump has come out in the first segment of this debate raring to go. Trump has interrupted nearly every answer being given by Hillary Clinton, talking over her time and again. Clinton is sticking to her guns, smiling while Trump speaks and then calling on people to go to her website and see the fact checking being done.

×