Add peanuts to in­fants’ diet, sci­en­tists say

More peo­ple are ex­pe­ri­enc­ing se­vere food al­ler­gies than ever be­fore, writes Matthew Smith ,a se­nior lec­turer in his­tory at the Univer­sity of Strath­clyde.

Otago Daily Times - - GENERAL - SEEK­ING AN­SWERS

WELLING­TON: Sci­en­tists are rec­om­mend­ing adding eggs and peanuts to in­fants’ di­ets in the first year of life to help pre­vent al­ler­gies.

New guide­lines by the Aus­tralasian So­ci­ety of Clin­i­cal Im­munol­ogy and Al­lergy sug­gests mak­ing the ad­di­tion af­ter four months of age.

Lead au­thor of the guide­lines pub­lished in The Med­i­cal Jour­nal of Aus­tralia, Preeti Joshi, said food al­lergy had been be­com­ing in­creas­ingly com­mon glob­ally and rates in Aus­tralia were among the high­est in the world.

‘‘There is an ur­gent need to pre­vent food al­lergy as there is no cur­rent cure. As such, any mea­sures which have proven ef­fi­cacy in pri­mary pre­ven­tion should be given sig­nif­i­cant con­sid­er­a­tion in public health pol­icy,’’ she said.

ASCIA pub­lished the guide­lines in 2016, and made ad­di­tions first in 2017 and again in 2018.

In its most re­cent rec­om­men­da­tions, Dr Joshi and her col­leagues said while pre­vi­ous rec­om­men­da­tions had been to avoid cer­tain al­ler­genic foods dur­ing early childhood, stud­ies had found lit­tle rea­son for that.

‘‘Dur­ing the 2000s, mul­ti­ple co­hort stud­ies re­ported find­ing no ev­i­dence that de­layed in­tro­duc­tion of al­ler­genic foods was as­so­ci­ated with re­duced rates of food al­lergy.

‘‘In 2008 a cross­sec­tional study re­ported that the preva­lence of peanut al­lergy was 10­fold higher among chil­dren in the UK (where in­fant peanut avoid­ance was rec­om­mended) com­pared with Is­raeli chil­dren of sim­i­lar an­ces­try (where peanut is usu­ally in­tro­duced at around 6­7 months)’’, the au­thors wrote.

Dr Joshi said there was now ‘‘mod­er­ate’’ ev­i­dence that reg­u­lar peanut in­take be­fore 12 months of age could re­duce the risk of de­vel­op­ing a peanut al­lergy.

A trial of 640 chil­dren be­tween 4 and 11 months of age with se­vere eczema, egg al­lergy or both, found those who avoided peanut­con­tain­ing foods were more likely to de­velop peanut al­ler­gies than those who did not.

‘‘The guide­lines rec­om­mend that par­ents should in­tro­duce peanut be­fore 12 months (but not be­fore 4 months) and sug­gest dis­cussing how to do this with the child’s doc­tor.

‘‘It is some­what re­as­sur­ing that there have been no re­ports of fa­tal­i­ties to peanut un­der 12 months of age any­where in the world, even in coun­tries that have prac­tised early in­tro­duc­tion of peanut (e.g., Is­rael) for many years.’’ — RNZ

THE re­cent in­quest into the death of Natasha Ed­nan­Lap­er­ouse (15) from ana­phy­laxis af­ter eat­ing a baguette she was un­aware con­tained se­same, could lead to a change in la­belling leg­is­la­tion in the United King­dom.

In­deed, a re­cent investigation found un­de­clared al­ler­gens were present in a quar­ter of foods sam­pled. But a more fun­da­men­tal is­sue needs to be ad­dressed: why are more peo­ple ex­pe­ri­enc­ing se­vere food al­ler­gies than ever be­fore?

As I ex­plain in An­other Per­son’s Poi­son: A His­tory of Food Al­lergy, strange re­ac­tions to food have long been known.

The An­cient Greek physi­cian Hip­pocrates (circa 460BC­370BC) de­scribed such re­ac­tions to var­i­ous foods, in­clud­ing cheese. Straw­ber­ries caused Richard III to break out into hives. It is said he once sneak­ily con­sumed ‘‘a messe of strauberies’’, and then blamed his re­ac­tion on witch­craft or­ches­trated by one of his op­po­nents, who was sum­mar­ily be­headed.

By the time Aus­trian physi­cian Cle­mens von Pir­quet coined the term ‘‘al­lergy’’ in 1906, many be­lieved food could trig­ger skin problems, asthma, gas­troin­testi­nal dis­tress and even men­tal dis­or­ders.

In the 1930s, food al­lergy emerged as a dis­tinc­tive sub­cat­e­gory of al­lergy. But it was also highly con­tro­ver­sial. Although it was easy to iden­tify the food at fault in ana­phy­lac­tic re­ac­tions, such as the one that killed Natasha Ed­nanLap­er­ouse, these sud­den re­ac­tions were rare.

Food al­ler­gists tended to fo­cus in­stead on pa­tients whose re­ac­tions were de­layed, oc­cur­ring up to 48 hours af­ter eat­ing the sus­pected food and, so, much more dif­fi­cult to di­ag­nose.

These re­ac­tions were typ­i­fied by symp­toms such as eczema, di­ar­rhoea, asthma, mi­graine and psy­chi­atric problems, in­clud­ing de­pres­sion and hy­per­ac­tiv­ity.

Many doc­tors, how­ever, doubted the claims of food al­ler­gists that food al­lergy was re­spon­si­ble for much un­di­ag­nosed chronic ill­ness.

In fact, some were so un­con­vinced they would re­fer pa­tients com­plain­ing of chronic food al­lergy to psy­chi­a­trists, be­liev­ing their symp­toms were psy­cho­so­matic. The heated de­bates that would emerge dur­ing the post­war pe­riod about the preva­lence of food al­lergy dis­tracted re­searchers from in­ves­ti­gat­ing the root causes of the con­di­tion. En­ter the peanut.

In the early 1980s, food al­lergy be­came a marginalised topic within medicine. Then, a new phe­nom­e­non emerged that forced doc­tors to take it se­ri­ously: peanut al­lergy.

In 1988, an ar­ti­cle in the Cana­dian Med­i­cal As­so­ci­a­tion Jour­nal de­scribed the case of a 24­year­old woman who died af­ter eat­ing a bis­cuit that con­tained peanut oil.

Although one or two sim­i­lar sto­ries had been re­ported pre­vi­ously in news­pa­pers, this was the first re­port made in a med­i­cal jour­nal. It would not be the last.

By the 1990s, peanut al­lergy fa­tal­i­ties were com­mon­place. Ac­cord­ing to US char­ity Food Al­lergy Re­search and Ed­u­ca­tion (Fare), rates of peanut and tree nut al­lergy tripled be­tween 1997 and 2008 among Amer­i­can chil­dren.

As a re­sult, food al­lergy be­came as­so­ci­ated with these se­vere, po­ten­tially fa­tal, al­ler­gies, rather than the chronic food al­ler­gies on which food al­ler­gists had pre­vi­ously con­cen­trated.

Fare and other al­lergy char­i­ties suc­cess­fully lob­bied for bet­ter la­belling, more peanut­free spa­ces (in schools for in­stance) and the avail­abil­ity of life­sav­ing epipens which ad­min­is­ter a dose of ep­i­neph­rine (a chem­i­cal that nar­rows blood ves­sels and opens air­ways in the lungs) to any­one suf­fer­ing an ana­phy­lac­tic re­ac­tion.

But they failed to con­vince sci­en­tists to con­duct de­tailed in­ves­ti­ga­tions into why such al­ler­gies were in­creas­ing so rapidly.

On the one hand, this re­luc­tance was un­der­stand­able.

There was a press­ing need to pro­vide new treat­ments and sup­port to the in­creas­ing num­ber of peo­ple suf­fer­ing from se­vere food al­ler­gies. On the other, sci­en­tists were hes­i­tant to in­ves­ti­gate a con­di­tion that had long been con­sid­ered a fad — a sus­pi­cious and di­vi­sive di­ag­no­sis that was too re­liant on pa­tient ac­counts for its jus­ti­fi­ca­tion.

While re­search con­tin­ues to ex­plore po­ten­tial cures and treat­ments, not enough effort has been spent on ex­plor­ing root causes.

Into the vac­uum have emerged some con­tro­ver­sial ex­pla­na­tions, many of which have not been based on much sci­en­tific re­search.

Pos­si­ble ex­pla­na­tions:

One sug­ges­tion is the hy­giene hy­poth­e­sis, which ar­gues that chil­dren grow up in ex­ces­sively clean en­vi­ron­ments, mean­ing their bod­ies strug­gle to dis­tin­guish be­tween harm­ful pathogens and harm­less pro­teins, such as those found in peanuts.

Oth­ers point to cook­ing tech­niques, in­di­cat­ing that peanut al­lergy is more com­mon in coun­tries where peanuts are roasted, rather than boiled.

In­fant feed­ing is also im­pli­cated, the most re­cent ad­vice be­ing that moth­ers with a fam­ily his­tory of al­lergy should in­tro­duce peanuts early on.

In­creased use of soya (a rel­a­tive of the peanut) in food pro­duc­tion has also been suggested.

But none of these ex­pla­na­tions have proved com­pletely con­vinc­ing, lead­ing to the emer­gence of even more con­tro­ver­sial hy­pothe­ses.

The truth is that we simply don’t yet know what is trig­ger­ing the peanut al­lergy epi­demic or in­creas­ing rates of food al­lergy.

A chief rea­son for this is a lack of open­minded re­search into the causes of al­lergy. The ex­pla­na­tions that emerge from such re­search might not be easy for peo­ple to ac­cept if they in­di­cate food al­lergy is a byprod­uct of mod­ern life­styles, new di­ets or changes in how peo­ple in­ter­act with their en­vi­ron­ment.

In­ves­ti­gat­ing the causes of food al­lergy will not be easy, but if medicine is to pre­vent more tragedies such as Natasha Ed­nan­Lap­er­ouse, it will be es­sen­tial. — the­con­ver­sa­tion.com

PHOTO: REUTERS

On the rise . . . A man cleans peanuts for sale out­side a shop in Peshawar.

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