Born to be thin?

The Star Early Edition - - FRONT PAGE -

SO­CIAL pres­sure to be as slen­der as a cat­walk model, as sylph-like as a Hol­ly­wood star, is said to be what drives anorexia, the so­called slim­mer’s dis­ease. An es­ti­mated one mil­lion peo­ple in Bri­tain suf­fer from the disorder, which has the high­est death rate – from sui­cide or star­va­tion – of any men­tal health con­di­tion.

In re­al­ity, there is no sin­gle so­cial cause. Psy­chol­o­gists say that anorexia may be driven by a fear of adult­hood or of los­ing the at­ten­tion of par­ents. It may rep­re­sent an at­tempt to ex­ert con­trol by in­di­vid­u­als who sense they lack it in other ar­eas of their lives.

But an area that re­mains rel­a­tively un­ex­plored is the ge­net­ics of the con­di­tion. Is anorexia in­her­ited and, if so, which genes are in­volved? De­spite decades of re­search into the ge­net­ics of other psy­chi­atric dis­or­ders, such as schizophre­nia, anorexia has had lit­tle at­ten­tion from the gene hunters.

Now Bri­tish and Amer­i­can re­searchers have joined forces with oth­ers around the world to launch the largest-ever study of the genes un­der­ly­ing anorexia. The aim is to gather 25 000 DNA sam­ples from suf­fer­ers and com­pare them with an un­af­fected con­trol group of 25 000.

The sci­en­tists hope that by pin­point­ing the genes re­spon­si­ble and iden­ti­fy­ing their func­tion, the re­search will point the way to new treat­ments. A study last year sug­gested that a choles­terol gene could play a role in the dis­ease, pro­vid­ing a po­ten­tial new tar­get for drug treat­ment. But the find­ing could not be repli­cated (and thus con­firmed), and the sci­en­tists are back at square one and the hunt be­gins again.

One ef­fect of the re­search, if it is suc­cess­ful, is that it could lessen the guilt that par­ents of­ten feel for a con­di­tion that is thought to de­rive from fac­tors in the en­vi­ron­ment and fam­ily back­grounds of suf­fer­ers.

Pro­fes­sor Janet Trea­sure, di­rec­tor of the Eat­ing Dis­or­ders Unit at the Beth­lem Royal Hos­pi­tal in London, says: “Guilt is a common feel­ing among par­ents. When it (anorexia) hap­pens on your watch in ado­les­cence, it is a nat­u­ral re­sponse.

“We know that anx­i­ety in the par­ents can con­trib­ute to anx­i­ety in the child. Th­ese emo­tional re­ac­tions are im­por­tant in al­low­ing the ill­ness to stick.”

But she cau­tions that too great an em­pha­sis on the ge­netic ba­sis of the ill­ness could cause par­ents to feel fa­tal­is­tic. “They could feel hope­less – we don’t want that. We know that there is a mix of en­vi­ron­men­tal and ge­netic causes of anorexia.”

Anorexia af­fects one to 2 per­cent of teenagers and univer­sity stu­dents, though it can oc­cur at any age. Anorex­ics se­verely re­strict eat­ing and be­come ema­ci­ated, yet see them­selves as fat. They se­cretly starve them­selves, some­times in­duc­ing them­selves to vomit after eat­ing, and usu­ally com­bine this with ex­ces­sive ex­er­cise. They may also take lax­a­tives.

Suf­fer­ers tend to be per­fec­tion­ists, anx­ious or de­pressed, and ob­ses­sive. The con­di­tion is 10 times more fre­quent among women than men and is com­mon­est among the daugh­ters of pro­fes­sional cou­ples.

Some ex­perts be­lieve that the biological ba­sis of anorexia has been un­der-em­pha­sised, and the so­cial causes over-stressed. Given the pres­sure on women to be thin in Western so­ci­eties, ev­ery­one would be anorexic if that were the only fac­tor, they say. Th­ese sci­en­tists say that some peo­ple are born with a biological pre­dis­po­si­tion to anorexia, which may run in fam­i­lies. Twin stud­ies have al­ready sug­gested a ge­netic link.

The global project to find the genes re­spon­si­ble, called AN 25 k, is led by Pro­fes­sor Cyn­thia Bu­lik, an ex­pert in eat­ing dis­or­ders at the Univer­sity of North Carolina in the US. In the UK, the project is spear­headed by re­searchers at King’s Col­lege, London, who have an­a­lysed the DNA of more than 300 for­mer anorexia suf­fer­ers.

The Bri­tish re­searchers have teamed up with the char­ity Char­lotte’s Helix to raise money for the project. The char­ity was set up in mem­ory of Char­lotte Be­van, who died of can­cer aged 48 in Jan­uary. Her daugh­ter, Ge­orgie, was di­ag­nosed with anorexia aged 12, and Char­lotte was con­vinced that Ge­orgie had in­her­ited the con­di­tion, but felt frus­trated by the lack of re­search. She set up the char­ity be­fore she died and wrote a book on anorexia for other par­ents, called Throw­ing Starfish Across the Sea.

“I want peo­ple to stop be­ing afraid

What ge­netic stud­ies can do is show that it is not all to do with how you grew up

and ashamed of some­thing that is not their fault. I want to ed­u­cate the 99 per­cent of the world that don’t know or don’t care that the eat­ing disorder world de­serves a voice.

“I want peo­ple to know that my daugh­ter is not a vain, mind­less bimbo who just wants to be thin, but a stel­lar, bril­liant, im­por­tant part of the com­mu­nity who just hap­pens to have a brain blip,” she wrote.

Se­nior King’s lec­turer Dr Gerome Breen, who is lead­ing the study in the UK, says: “Re­search on anorexia is where it was on schizophre­nia 20 years ago. There has been a lot of small stud­ies pro­duc­ing re­sults that don’t get repli­cated (con­firmed). What we need is a re­ally large sam­ple size.”

The project is likely to re­veal hun­dreds of genes that con­trib­ute to the con­di­tion, some more strongly as­so­ci­ated with it than oth­ers. The larger the sam­ple of anorexia suf­fer­ers, the bet­ter the chance of es­tab­lish­ing strong ge­netic links.

“We hope we find ge­netic hits that point the way to the biological sys­tems we need to tar­get to de­velop new treat­ments. Stud­ies show 56 per­cent of the risk of anorexia is con­trib­uted by ge­netic fac­tors. If there were one gene as­so­ci­ated with the ill­ness, we would have found it al­ready,” he says.

“What we see in many dis­eases, from breast can­cer to di­a­betes, is lots of dif­fer­ent genes, each con­tribut­ing a small part of the risk. It won’t pre­dict who will be­come anorexic. But what ge­netic stud­ies do best is point to the un­der­ly­ing bi­ol­ogy of the ill­ness.”

The stigma at­tached to the ill­ness has a dam­ag­ing ef­fect on fam­i­lies, and un­cov­er­ing its ge­netic ba­sis could help al­le­vi­ate that, Breen says.

“Par­ents have got the im­pres­sion that they are be­ing blamed. It may not be true, but that is the im­pres­sion they have got. A cul­ture used to ex­ist of blam­ing par­ents. Ge­netic stud­ies can show that it is not all to do with how you grew up.

“In can­cer, de­men­tia and schizophre­nia, we are us­ing re­search tools to tar­get the bi­ol­ogy of the ill­ness, the work­ing of the brain or the de­vel­op­ment of new psy­cho­log­i­cal ther­a­pies. – The In­de­pen­dent

THE LEAN LOOK: A very thin model turns on the run­way in New York, an im­age that has fu­elled so­ci­ety’s ideal of the “coathanger” woman.

Pic­ture: Stu­art Ram­son / AP

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