The World’s Oldest Clinical Trial Showed the Value of a Vegan Diet!

Clin­i­cal tri­als are a cru­cial part of the mod­ern sci­en­tif­ic method. Yet the ear­li­est record­ed clin­i­cal tri­al, which inci­den­tal­ly dealt with food, was con­duct­ed around 2600 years ago, in ancient Baby­lon. There were no sci­en­tif­ic jour­nals back then, but we know about the study because it was report­ed in a book that is revered by Jews, Chris­tians, and Mus­lims. I’m talk­ing about the Book of Daniel, which is part of the Hebrew Bible and the Chris­t­ian Old Tes­ta­ment.

The Book of Daniel is about the Baby­lon­ian Cap­tiv­i­ty, when Neb­uchad­nez­zar II of Baby­lon con­quered Judah and Jerusalem and sent the Jews into exile, in rough­ly the year 600 BC. Dur­ing this peri­od, it would have been cus­tom­ary to take some of the sons of promi­nent peo­ple from the con­quered lands and hold them hostage in court. This explains how Daniel and sev­er­al oth­er Hebrews end­ed up in Nebuchadnezzar’s court. They weren’t there vol­un­tar­i­ly. Lat­er on, Psalm 137 described this peri­od as fol­lows:

For there they that car­ried us away cap­tive required of us a song; and they that wast­ed us required of us mirth, say­ing, Sing us one of the songs of Zion. How shall we sing the Lord’s song in a strange land?

One of the biggest prob­lems that Daniel and his fel­low cap­tives faced in the court of Neb­uchad­nez­zar was the fact that they would have been expect­ed to eat the food that was being served in court. For devout Jews, of course, this was noth­ing short of blas­phe­my. To eat the food at court meant that they would be eat­ing meat from ani­mals that had been sac­ri­ficed to pagan gods and drink­ing wine that had like­wise been offered to for­eign gods. In oth­er words, by eat­ing the food at court, they would be vio­lat­ing their own reli­gion and tak­ing part in the reli­gion of their cap­tors. To refuse to eat the food at court would thus be a risky act of civ­il dis­obe­di­ence.

Daniel’s chal­lenge was to fig­ure out some way in which he could get per­mis­sion for him­self and the oth­er Hebrews to avoid offend­ing either God or Neb­uchad­nez­zar. He decid­ed that he and his friends should eat only “food that comes from seeds” (i.e., veg­eta­bles and fruit and grains and puls­es, such as peas) and drink only water. Thus, they would avoid the meat and wine that were rit­u­al­ly unclean because they had been used in rit­u­als for pagan gods. The over­seer in charge of Daniel and his friends was reluc­tant to let them fol­low this strict diet. He was afraid it would ruin their health, thus land­ing him in big trou­ble. So Daniel sug­gest­ed a sim­ple exper­i­ment. He and his friends would eat plant foods and water for 10 days, and after­ward their health would be com­pared with that of the peo­ple con­sum­ing meat and wine.

Accord­ing to the Book of Daniel, after 10 days Daniel and his friends looked health­i­er than the youths who had been eat­ing the king’s food. It also says that they were “fat­ter,” but it’s more like­ly that they would have been thin­ner than the peo­ple who were pig­ging out on “the king’s dain­ties.” It’s easy to gain too much weight on a meaty diet, but it’s hard to get fat on a starchy, high-fiber diet. How­ev­er, that small inac­cu­ra­cy prob­a­bly result­ed from the fact that the study report was pub­lished rough­ly four cen­turies after the study itself was com­plet­ed. As a recent arti­cle on this study not­ed, “Daniel per­ished, then pub­lished.” [1] With tongue firm­ly in cheek, the arti­cle also not­ed that the method­olog­i­cal weak­ness­es of the study include “prob­a­ble selec­tion bias, ascer­tain­ment bias, and con­found­ing by divine inter­ven­tion.”

About 2600 years after Daniel’s exper­i­ment, a group of researchers in the Unit­ed States did rough­ly the same exper­i­ment, this time com­par­ing Daniel’s diet with the stan­dard dietary rec­om­men­da­tions of the Amer­i­can Dia­betes Asso­ci­a­tion, which allows peo­ple to eat con­trolled por­tions of “the king’s dain­ties.” [2] This study dif­fered in sev­er­al ways from the study report­ed in the Book of Daniel. The mod­ern study involved peo­ple with type 2 dia­betes, which is a dis­ease that is known to be linked to obe­si­ty and a fat­ty diet. The sub­jects were ran­dom­ly assigned to either the Daniel-type diet or the ADA diet. Also, the tri­al last­ed longer than 10 days, to show improve­ments in the sub­jects’ gly­co­sy­lat­ed hemo­glo­bin lev­els (HbA1c) and to pro­vide a clear pic­ture of how much weight they lost and how many pre­scrip­tion drugs they could stop tak­ing.

I was not at all sur­prised to see that a diet like Daniel’s was far more effec­tive than the ADA’s stan­dard rec­om­men­da­tions at improv­ing the health of peo­ple with type 2 dia­betes. What sur­prised me was that the par­tic­i­pants were more suc­cess­ful at stick­ing to the Daniel-style diet. This suc­cess prob­a­bly stemmed from the fact that although people’s food choic­es were lim­it­ed, their por­tions were not. The ADA dietary rec­om­men­da­tions are about por­tion con­trol, which most peo­ple can’t achieve. The Daniel diet lets peo­ple eat to their heart’s con­tent, while still los­ing weight.

Ref­er­ence List
1. Grimes DA. Clin­i­cal research in ancient Baby­lon: method­olog­ic insights from the book of Daniel. Obstet Gynecol. 1995;86(6):1031–1034.
2. Barnard ND, Cohen J, Jenk­ins DJ et al. A low-fat veg­an diet improves glycemic con­trol and car­dio­vas­cu­lar risk fac­tors in a ran­dom­ized clin­i­cal tri­al in indi­vid­u­als with type 2 dia­betes. Dia­betes Care. 2006;29(8):1777–1783.

Pho­to by diff_sky