An an­cient trav­eler’s final meal

Anal­y­sis of Ice­man’s stom­ach con­tents may of­fer new in­sight into heart dis­ease’s ori­gins.

Los Angeles Times - - CALIFORNIA - MELISSA HEALY melissa.healy@latimes.com

If you were think­ing that the an­cient Alpine trav­eler known as Otzi — and of­ten known sim­ply as Ice­man — scraped by on a diet of for­aged grasses and berries, you’d be very wrong.

A com­pre­hen­sive new study of his stom­ach con­tents re­veals that Otzi, who per­ished roughly 5,300 years ago on a moun­tain in the Eastern Alps of Italy, died with a belly full of fatty meat, some whole seeds from the einkorn wheat plant, and maybe a bit of goat’s milk or cheese — all eaten just a cou­ple of hours be­fore he died.

Judg­ing from the rem­nants of plant spores found in his gut, the Ice­man may have set off from home with a mo­bile meal of smoked or dried meat wrapped in the large, coarse leaves of a bracken fern.

It was not a bad pic­nic for a peri­patetic mem­ber of a prim­i­tive so­ci­ety of hunter-gath­erer-farm­ers. There were traces of herbs, per­haps used to fla­vor the meat or a bread made from grains we would now call “an­cient.” The meat came from an ibex — a wild goat species also known as the stein­bock — and red deer, both plen­ti­ful in the area.

So much for some re­searchers’ con­vic­tion, based on an early anal­y­sis of his hair, that Otzi was a veg­e­tar­ian. Close to half of what re­mained in his stom­ach was fat from the meats he con­sumed. That fat would have given his last meal the lux­u­ri­ous mouth­feel of ba­con.

The mus­cle-and-heart meat would have de­liv­ered the sa­ti­at­ing prop­er­ties of pro­tein. It was fuel well­suited to the rig­ors of stalk­ing, hunt­ing and pos­si­bly shep­herd­ing an­i­mals in the cold, high Alps.

In time, this fatty, car­niv­o­rous diet would prob­a­bly have clogged Otzi’s ar­ter­ies, and ev­i­dence that this process was al­ready un­der­way has come from ear­lier re­search. But since Ice­man was un­likely to sur­vive into any­thing re­sem­bling mod­ern-day old age, that would prob­a­bly not have been the death of him. (He is es­ti­mated to have been roughly 45 when he died and had prob­a­bly out­lived most of his con­tem­po­raries.)

As food-pack­ag­ing goes, bracken fern is a more ques­tion­able choice: It can cause bleed­ing and ane­mia when in­gested.

But what killed Otzi in the end ap­pears to have been an ar­row to the back. And what hap­pened at some point fol­low­ing his death — ei­ther a de­lib­er­ate burial or a final ac­ci­den­tal fall into a glacial ravine — caused his re­mains to be frozen and mum­mi­fied un­til their dis­cov­ery by hik­ers in 1991.

Dr. Gre­gory S. Thomas, a car­di­ol­o­gist with Me­mo­ri­alCare Heart and Vas­cu­lar In­sti­tute in Long Beach who has stud­ied an­cient spec­i­mens to dis­cern the roots of heart dis­ease, calls Otzi “the best pre­served an­cient mummy ever dis­cov­ered.” The new find­ings, re­ported this week in the jour­nal Cur­rent Bi­ol­ogy, will in­spire sci­en­tists “to look into the last meals of mum­mies from other an­cient cul­tures,” he said.

Thomas, who was not in­volved in the re­search, said the study will help an­swer age-old ques­tions of univer­sal in­ter­est: What is an ideal diet, and how does what we eat in­flu­ence our health, en­ergy and abil­ity to sur­vive in the spa­ces and times we in­habit?

Pre­served in ice for mil­len­ni­ums and thawed out only for the oc­ca­sional well-planned study, Otzi has given the mod­ern world its best-ever chance to ex­plore the ev­ery­day re­al­i­ties of life dur­ing the Chal­col­ithic era. Stretch­ing from roughly 3500 to 2300 BC, that tu­mul­tuous pe­riod marked South­ern Europe’s tran­si­tion from prim­i­tive farm­ing with stone tools to civ­i­liza­tions that forged met­als, ex­panded trade and ush­ered in com­plex mod­ern so­ci­eties.

Ice­man’s mum­mi­fied re­mains have been in­ten­sively stud­ied, and ear­lier sur­veys had al­ready yielded some clues about his diet. But those analy­ses fo­cused on the con­tents of Ice­man’s lower in­testines, the largely di­gested re­mains of food eaten at least eight hours ear­lier, in­clud­ing deer meat, grains and fruit.

Those stud­ies also showed that Ice­man was in­fected with an in­testi­nal par­a­site called whip­worm, and that he was lac­tose in­tol­er­ant. And they helped trace a turn­ing point in hu­mankind’s den­tal health: the in­tro­duc­tion of grain­derived car­bo­hy­drates, which prob­a­bly had de­posited cav­ity-caus­ing sug­ars on Ice­man’s teeth.

The new anal­y­sis was made pos­si­ble by the dis­cov­ery of Ice­man’s stom­ach, which had in­ex­pli­ca­bly mi­grated up­ward dur­ing the mum­mi­fi­ca­tion process.

Re­searchers from the In­sti­tute for Mummy Stud­ies in Bolzano, Italy, where Ice­man’s re­mains are stored, spot­ted the elu­sive stom­ach when they were re­view­ing CT scans in 2009. That prompted an in­ten­sive anal­y­sis of its con­tents. The team, led by Frank Maixner and Al­bert Zink, em­ployed meth­ods in­clud­ing mi­cro­scopic ob­ser­va­tion and ge­nomic anal­y­sis.

Otzi’s final meal, the au­thors con­cluded, was “a well-bal­anced mix of car­bo­hy­drates, pro­teins and fats per­fectly ad­justed to the en­er­getic re­quire­ments of his high al­ti­tude trekking.”

The tools brought to bear in the new study gave Maixner and Zink the abil­ity “to ex­am­ine the DNA, pro­tein, car­bo­hy­drate and fat down to the atomic level,” Thomas said. “In the past, we could peer into a mi­cro­scope and look at the meat of an an­cient meal. But we could not ex­am­ine the DNA, for ex­am­ple, to de­ter­mine which an­i­mal it was, and which part of the an­i­mal.”

The find­ings touched off a new round of ex­cited chat­ter among those who study an­cient hu­man cul­tures to dis­cern the ori­gins of heart dis­ease.

“He would need the fat as an en­ergy source, and I am sure he would have burned it off,” said Dr. Anthony Hea­gerty, a car­di­ol­o­gist and pro­fes­sor of medicine at the Univer­sity of Manch­ester in England. Analy­ses of Otzi’s bones sug­gest that his lifestyle was far from seden­tary and in­cluded long walks over hilly ter­rain.

“It is in­ter­est­ing that scans of the Ice­man have shown ma­jor cal­ci­fi­ca­tion in ar­ter­ies and the aorta in­di­cat­ing an ad­vanced state of atheroscle­rotic dis­ease,” Hea­gerty said. In the end, he died vi­o­lently, but “he too was in dan­ger of heart at­tack,” Hea­gerty spec­u­lated. Thomas is not so sure. The meats found in Ice­man’s belly — the heart and mus­cle meat of ibex and red deer — “were both wild and lean,” he said. And re­cent stud­ies, in­clud­ing re­search on the car­dio­vas­cu­lar health of the Tsi­mane peo­ple of low­land Bo­livia, sug­gest that when it comes to heart dis­ease, it may be the fat con­tent of meat, more than the quan­tity con­sumed, that mat­ters.

While the farmer-for­ager Tsi­mane eat about the same per­cent­age of pro­tein as in the typ­i­cal Amer­i­can diet, the fat con­tent of the meats they eat is about half of that found in farm-fed an­i­mals in the United States, Thomas said.

Fi­nally, even at the thenad­vanced age of roughly 45, Otzi ap­peared to be “a life­time ath­lete” for whom 10,000 steps a day “would likely be al­most a warm-up,” he said.

M. Sa­madelli South Ty­rol Ar­chae­ol­ogy Mu­seum/Eu­rac

SCI­EN­TISTS study Otzi, of­ten called Ice­man, in 2010. He died roughly 5,300 years ago. His last meal in­cluded fatty meat and some einkorn wheat plant seeds.

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