Vitamin B3 (niacin)

Dermatitis from pellagra

Dur­ing the first few decades of the twen­ti­eth cen­tu­ry, a defi­cien­cy dis­ease called pel­la­gra, which is caused by lack of niacin (vit­a­min B3), sick­ened near­ly 5 mil­lion Amer­i­cans and caused per­haps 150,000 need­less deaths. This dis­ease had occurred spo­rad­i­cal­ly wher­ev­er poor peo­ple depend­ed too heav­i­ly on corn (maize) as a sta­ple food—except in Mex­i­co, for rea­sons I’ll explain below.

The Great Pel­la­gra Epi­dem­ic in the Unit­ed States broke out in earnest after the inven­tion of the Beall degermi­na­tor in 1906. The epi­dem­ic wors­ened in 1921 because of the post­war col­lapse of cot­ton prices and peaked in the wake of cat­a­stroph­ic flood­ing in the Mis­sis­sip­pi Val­ley in 1927, which forced near­ly a mil­lion peo­ple from their homes. The epi­dem­ic per­sist­ed through the Dust Bowl of the ear­ly 1930s and then start­ed to decline, part­ly because the decline in cot­ton prices encour­aged farm­ers to grow more food instead of just cot­ton. The epi­dem­ic final­ly end­ed at the onset of World War II, part­ly because of ris­ing incomes and part­ly because of the vit­a­min enrich­ment of processed grain prod­ucts.

Corn has been grown in what is now Mex­i­co for thou­sands of years. As the great Mex­i­can poet Ramón López Velarde wrote, Patria: tu super­fi­cie es el maíz (my coun­try, your sur­face is corn). The Mex­i­can peo­ple have depend­ed heav­i­ly on corn since the dawn of Mesoamer­i­can civ­i­liza­tion, yet pel­la­gra is vir­tu­al­ly unknown there. That’s because in Mex­i­co, corn is tra­di­tion­al­ly treat­ed by a process called nix­ta­mal­iza­tion. The corn ker­nels are soaked in an alka­line solu­tion, made from cal­ci­um oxide or wood ash­es. The alka­line solu­tion helps to soft­en the corn ker­nels, mak­ing them eas­i­er to grind. It also helps make the corn more digestible and less sus­cep­ti­ble to attack by molds and fun­gi. Plus, it makes the corn taste bet­ter.

For­tu­nate­ly, you don’t have to go to all this trou­ble your­self. The masa hari­na that I use to make corn tor­tillas has already under­gone nix­ta­mal­iza­tion. All I have to do is add water and plop a ball of dough on my elec­tric tor­tilla press. Unfor­tu­nate­ly, when the Span­ish intro­duced corn to oth­er parts of the world, they didn’t intro­duce the nix­ta­mal­iza­tion process with it. As a result, Euro­peans and oth­ers who start­ed depend­ing too heav­i­ly on corn as a sta­ple food were prone to a dis­ease called pel­la­gra, which means “rough skin” in Ital­ian.

The rough skin, or der­mati­tis, was only one of the “four D’s” of pel­la­gra. The oth­ers were diar­rhea, demen­tia, and death. At first, pel­la­gra was mis­tak­en­ly thought to be infec­tious. Then, when peo­ple noticed that it tend­ed to occur in poor fam­i­lies and in pris­on­ers and men­tal patients, it was mis­tak­en­ly thought to be genet­ic. In the hey­day of the eugen­ics move­ment dur­ing the 1920s, some emi­nent sci­en­tists denied the increas­ing­ly com­pelling evi­dence that pel­la­gra was due to a nutri­ent defi­cien­cy, claim­ing instead that feed­ing poor peo­ple would only lead to an increase in pel­la­gra, because it would enable “pel­la­grins” to have more chil­dren.

In the Unit­ed States, pel­la­gra occurred main­ly in the South, among the des­per­ate­ly poor and among peo­ple con­fined to pris­ons or men­tal insti­tu­tions. The dis­ease result­ed from a diet that con­sist­ed of lit­tle oth­er than corn­meal fla­vored with a tiny bit of salt pork (not enough to pro­vide enough niacin) and black molasses. This was the inspi­ra­tion for the tra­di­tion­al blues song “Corn­meal, Meat, and Black Molasses.” Peo­ple who could afford to include vir­tu­al­ly any­thing else in their diet sim­ply didn’t get pel­la­gra. It’s inter­est­ing that the song is often sung as “Corn­meal, peas, and black molasses.” Peas are a good, cheap source of niacin and would have pre­vent­ed pel­la­gra.

Although cas­es of pel­la­gra had been occur­ring in the Unit­ed States for many years, the epi­dem­ic explod­ed after 1906, with the intro­duc­tion of the Beall degermi­na­tor. This equip­ment for pro­cess­ing corn removed the oily “germ” or embryo from the rest of the corn ker­nel. The corn germ could then be used for mak­ing corn oil, and the remain­ing corn­meal was bet­ter able to resist spoilage. Unfor­tu­nate­ly, this defat­ted corn­meal was also much low­er in niacin than reg­u­lar corn­meal. This removal of a source of niacin from an already defi­cient diet was a pub­lic health dis­as­ter.

The cure for pel­la­gra was dis­cov­ered by a coura­geous employ­ee of the U.S. Pub­lic Health Ser­vice, Dr. Joseph Gold­berg­er. To prove that pel­la­gra was not con­ta­gious, he inoc­u­lat­ed him­self, his wife, and some vol­un­teers from the Pub­lic Health Ser­vice with mate­r­i­al from the skin lesions and nasal secre­tions of peo­ple with pel­la­gra. They even went so far as to eat feces from peo­ple with pel­la­gra. Yet nobody got pel­la­gra as a result. Gold­berg­er then recruit­ed vol­un­teers at a prison in Mis­sis­sip­pi. In 1923, he report­ed that feed­ing the men noth­ing but corn­meal, fat­back, and molasses caused pel­la­gra, which was then cured by feed­ing the men oth­er foods, such as peas, beans, col­lard greens, and wheat bread. By 1926, Gold­berg­er pro­posed that yeast extract be used to pre­vent and treat pel­la­gra. The pre­cise nutri­ent that was respon­si­ble for cur­ing pel­la­gra was even­tu­al­ly iden­ti­fied in 1937.

Goldberger’s exper­i­ments pro­vid­ed com­pelling sci­en­tif­ic evi­dence that pel­la­gra was caused by a nutri­tion­al defi­cien­cy and could be cured by a healthy diet or by nutri­ent sup­ple­ments. Yet many promi­nent mem­bers of the Amer­i­can sci­en­tif­ic com­mu­ni­ty refused to accept Goldberger’s con­clu­sions. Unfor­tu­nate­ly, the only way to end the pel­la­gra epi­dem­ic was to increase the incomes of the poor­est peo­ple in the Unit­ed States—especially the share­crop­pers and mill­work­ers of the South—so that they could afford to eat a healthy diet. Peo­ple who could afford to eat any­thing besides corn­meal fla­vored with molasses and a lit­tle bit of fat­back gen­er­al­ly did so, and thus avoid­ed pel­la­gra. Unfor­tu­nate­ly, increas­ing the incomes of share­crop­pers and mill­work­ers meant low­er prof­its for their employ­ers.

Dur­ing the cat­a­stroph­ic flood­ing of the Mis­sis­sip­pi Riv­er in 1927, Gold­berg­er advised the Red Cross to add yeast extract to the food rations that it was dis­trib­ut­ing to peo­ple who had been dev­as­tat­ed by the flood. The yeast extract rapid­ly cured pel­la­gra and pre­vent­ed new cas­es. Unfor­tu­nate­ly, it wasn’t avail­able to every­one. Black men who went to a Red Cross camp for relief ran a seri­ous risk of being tak­en from their fam­i­lies and forced to do unpaid labor at gun­point.

After 1923, it was obvi­ous to any­one not com­plete­ly blind­ed by a racist, right-wing polit­i­cal agen­da that pel­la­gra was a result of vit­a­min defi­cien­cy, and that it could be pre­vent­ed and cured by any rea­son­able diet. The devel­op­ment of yeast extracts as a mul­ti­vi­t­a­min sup­ple­ment made it pos­si­ble to “enrich” grains (i.e., to add back the vit­a­mins that had been stripped out of the grains by pro­cess­ing). After chemists iso­lat­ed the indi­vid­ual vit­a­mins and fig­ured out how to make large quan­ti­ties of them cheap­ly, enrich­ment of processed grain prod­ucts became even cheap­er and eas­i­er.

Although food enrich­ment pro­pos­als were fierce­ly resist­ed at first, the U.S. gov­ern­ment start­ed requir­ing enrich­ment of any food prod­ucts that it was buy­ing for mil­i­tary use. Thus, enrich­ment of grain prod­ucts became just part of the price of admis­sion for get­ting valu­able con­tracts with Uncle Sam. As a result, enrich­ment of grain prod­ucts became rou­tine in the Unit­ed States, and pel­la­gra was vir­tu­al­ly wiped out.

Today, pel­la­gra is extreme­ly rare in the Unit­ed States. The rare cas­es that occur today are main­ly in alco­holics, in peo­ple who have eat­ing dis­or­ders or are fol­low­ing “fad” diets, and in peo­ple who can’t absorb enough vit­a­mins from their food or who have trou­ble con­vert­ing tryp­to­phan to niacin. Pel­la­gra is com­mon in peo­ple with anorex­ia, and it may make the anorex­ia worse. The lack of niacin can end up trig­ger­ing the release of hunger-sup­press­ing hor­mones that make it eas­i­er for peo­ple to starve them­selves.

Both pel­la­gra and beriberi are B vit­a­min defi­cien­cy syn­dromes that result from peo­ple depend­ing too heav­i­ly on a sin­gle, improp­er­ly processed grain as a sta­ple food. Orig­i­nal­ly, both of these dis­eases were mis­tak­en­ly believed to be the result of pro­tein defi­cien­cy, because peo­ple who could afford to buy and eat ani­mal-based foods didn’t get either dis­ease. Yet it’s easy to get thi­amine and niacin from plant sources. That’s because the plants them­selves need those vit­a­mins for their own metab­o­lism, and they make their own sup­ply. Plants also con­tain all of the essen­tial amino acids. It’s vir­tu­al­ly impos­si­ble to get a pro­tein defi­cien­cy on any rea­son­able diet of whole plant foods.