Pellagra

Decoding a Turn-of-the-Century Mystery

Offer someone sow bellies and cornmeal grits for dinner tonight, and you'll probably find yourself eating alone. But in the deep South less than 100 years ago, these foods were the staple diet that's thought to have caused an outbreak of a niacin-deficiency disease called pellagra.

Characterized by a progressive decline that often starts with itchy, red skin, moves on to diarrhea and depression and ends in death, pellagra afflicted more than 100,000 people in 1914.

"The incidence was of such alarming proportions that the U.S. Surgeon General called for a special investigation of 'one the knottiest and most urgent problems of the present time,' " says Marvin Davis, Ph.D., chairman of the Department of Pharmacology at the University of Mississippi at Oxford.

An experiment involving orphans in Jackson, Mississippi, who had pellagra soon provided clues to the mystery. Just a few days after doctors added milk, meats and eggs to the corn grit diet of the children, their pellagra disappeared, says Dr. Davis.

To confirm dietary deficiency as a cause, another study was conducted, this time involving convicts. When pellagra-free prisoners agreed to eat nothing but sow bellies, corn grits, gravy and fried mush for five months, nearly all developed pellagra.

To eliminate lingering doubts that pellagra might be an infectious disease, Dr. Davis says, still another study was launched involving convicts. The prisoners, and the experimenters themselves, were injected with blood from people with pellagra or were exposed to their nasal or throat excretions. When the subjects didn't come down with the disease, researchers realized that pellagra could not possibly be infectious.

True Grits Not Enough

Although researchers soon figured that poor diet was causing pellagra, it wasn't until 1937 that researchers pinpointed the exact source of the problem. Corn not only contains a form of niacin, a B vitamin, that the body cannot easily use but also can create an amino acid imbalance, says Dr. Davis. Amino acids are the building blocks of protein, the stuff of which the body is made.

Eating corn as part of a well-balanced diet is not a problem, but a diet that consists almost exclusively of corn and corn products is devastating. In fact, the turn-of-the-century pellagra tragedy led to the fortification of flours and cereals with niacin. As a result, pellagra is now rare.

A few people still get pellagra, however, for reasons that have nothing to do with eating corn. Alcoholics and individuals with severe gastrointestinal problems often have difficulty getting enough niacin. Even then, diagnosing pellagra is not easy. The early symptoms, such as reddening of the skin, cracked lips, weight loss, tiredness, confusion and mild diarrhea, can be subtle, says William M. Hendricks, M.D., director of the Asheboro Dermatology Clinic in North Carolina.

Niacin to the Rescue

Fortunately, the effects of early-stage pellagra are easily reversed. "In general, the main therapy is to get patients back on a healthy diet and, in the case of alcoholics, to get them off of their alcohol and on to some kind of niacin supplementation," says Dr. Hendricks. (For the full story on the role of nutrients in treating alcoholism, see page 69.) He generally prescribes niacinamide, a form of niacin that's known not to produce undesirable side effects.

For severe cases, Dr. Hendricks recommends 100 milligrams of niacinamide three or four times daily for several weeks. Since high amounts of niacin can be toxic, he suggests that this amount be taken only under the supervision of a physician.

The amount of niacinamide a person with pellagra should take really depends on the condition of the individual and should be determined by a doctor, he says.

Some of the best food sources of niacin are chicken breast, tuna and veal. The Daily Value for niacin is 20 milligrams.