PREVENTIVE MEDICINE 18, 877-883 (1989)
The Prevention and Conquest of Scurvy, Beri-Beri, and Pellagra
THOMAS H. JUKES, PH.D. Departments of Biophysics and Nutritional Sciences, Universiv of California,
Berkeley, California 94720
The discovery and synthesis of vitamins has given human beings the potential to abolish some of the age-old scourges of disease. In some cases, this possibility has been largely realized, but the victory is yet incomplete.
Vitamins are defined as compounds of carbon that are needed in the diet to prevent the occurrence of deficiency diseases that develop in their absence. The amounts needed are small, in the range of milligrams per day or even less. The amino acids are not included in the category of vitamins, although deficiencies of some of the indispensable amino acids produce symptoms that resemble cer- tain vitamin deficiencies. Similar deficiencies are also produced by a lack of nutritionally essential mineral elements, but, again, these, by definition, are not vitamins.
Vitamin deficiency diseases were well known for many years before their causes were discovered. A well-known example is that of scurvy. A brief descrip- tion of how some of the important vitamin deficiencies were recognized and overcome follows.
VITAMIN C (ASCORBIC ACID)
Scurvy probably had its origin when human beings adopted agriculture, and moved into the temperature zones where the winters were long. It was possible to store grains for consumption during the long winters when crops could not be grown, but grains are lacking in the antiscurvy vitamin, C. An important event in lowering scurvy in Europe was the introduction of the potato from the New World. Potatoes are a moderately good source of vitamin C, and can be kept through the winter. A more conspicuous occurrence of scurvy was its develop- ment by sailors on long voyages where they had no fresh foods. Scurvy on board ships caused great suffering and many deaths. Eventually, the French explorer Jacques Cartier learned of a remedy for scurvy from the Indians of Lower Can- ada. The remedy was prepared by extracting the needles of coniferous trees, such as cedars, with hot water. It was easily possible to prepare this concoction in the dead of winter. By this means, in 1540, Cattier saved the lives of many of his companions. About two centuries later, the surgeon, James Lind, who was an officer in the British Navy, searched for a cure for this disease that was devas-
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878 THOMAS H. JUKES
tating the sailors. He reported in 1753 that the juice of limes and lemons was highly effective. After the inevitable and seemingly interminable bureaucratic delays and resistance, this discovery was adopted for use in 1804 by the British Navy, and English sailors became known as limeys, in allusion to their con- sumption of lime juice. The soubriquet eventually became an epithet, but regard- less of whether it was because of Linds discovery, the British Navy gave a good account of itself for many years after the introduction of lime juice.
Linds discovery presented scientists with the opportunity to open up a brand new field of research, which they proceeded to ignore completely for 150 years. In 1903, Holst and Frohlich observed that scurvy could be produced in guinea pigs by feeding them a diet of rolled barley and dried skim milk. A few years later, several investigators, including F. G. Hopkins and Casimir Funk (l), proposed the vitamin theory (see below). The use of guinea pigs as test animals enabled vitamin C to be isolated and identified.
This identification was delayed for 4 years by strange circumstances. Albert Szent-Gyorgyi, working for his doctorate in the laboratory of Hopkins at Cam- bridge in 1928, isolated a crystalline acidic compound, related to monosaccha- rides, from the cortices of adrenal glands. At the instigation of Hopkins, he sent a sample to S. S. Zilva in the Lister Institute, London, who was regarded as a leading authority on vitamin C, and especially on testing for it with guinea pigs. Zilva reported that Szent-Gyorgyis compound, hexuronic acid, was not vita- min C. Subsequently, C. G. King selected lemon juice as a source from which to isolate vitamin C. One of his students, J. Svirbely, left Kings laboratory in Pitts- burgh and went to Hungary, where he asked Szent-Gyorgyi for a job. Svirbely said that he knew how to test for vitamin C with guinea pigs. He therefore tested Szent-Gyorgyis hexuronic acid, and found that it was indeed vitamin C. Simul- taneously, King obtained crystalline vitamin C from lemon juice and announced that it seemed to be identical with Szent-Gyorgyis hexuronic acid. These findings were published almost simultaneously in 1932 by King and Waugh, and by Svir- bely and Szent-Gyorgyi. Szent-Gyorgyi then discovered that it was possible to isolate large quantities of vitamin C from sweet peppers. The vitamin was syn- thesized by Haworth, Hirst, and their collaborators in England and by Reichstein in Germany, and it was named ascorbic acid. It could be prepared cheaply and concurrent advances in scientific agriculture led to wider availability of foods that were good sources of vitamin C. The threat of scurvy vanished, and today it is a rare disease.
The annual tomato crop in California is more than 7 million metric tons, sufft- cient to supply 20 mg of vitamin C per capita daily to the U.S. population. Ten milligrams is enough to prevent or cure scurvy. Huge doses of synthetic vitamin C are consumed by people who evidently believe that it is a universal remedy, and that if a little is good, more must be better. For more information on the history of vitamin C and scurvy, see Carpenter (2) and Jukes (3).
VITAMIN B, (THIAMINE)
Like vitamin C, vitamin B , (4) has a naval history. Vitamin B , deficiency causes the disease, beri-bet-i, which is associated with polished rice consumption. The outer coats of rice are discarded in its preparation for human consumption, be-
HISTORICAL PERSPECTIVES 879
cause the oil in the outer coats produces rancidity. This procedure also led to the removal and loss of vitamin B,. Diets consisting mainly of polished rice, not supplemented with sources of thiamine, led to the wide occurrence of beri-beri in rice-consuming countries.
During 1878 to 1883, the incidence of beri-beri was 23 to 40% in the Japanese navy. In 1884, K. Takaki, Surgeon-General of the Japanese Navy, was able to eradicate this high incidence by a change in the diet which at that time consisted principally of polished rice. He obtained permission to substitute a moderate amount of meat and legumes for a portion of the rice, following which beri-beri disappeared almost completely. Takakis opinion was that the improvement re- sulted from an increase in the protein content of the diet. So firmly entrenched was the germ theory of disease that, despite these results, beri-beri continued to be regarded widely as being caused by infection.
C. Eijkman, working in Java, showed that a paralytic condition resembling beri-beri could be produced in chickens by feeding them a diet consisting solely of polished rice. He also showed that the disease, polyneuritis, did not develop if the chickens were fed on unpolished rice and that it could be prevented by adminis- tration of rice polishings to birds on the polished rice diet. Eijkman recognized the similarity of polyneuritis in chickens to the disease beri-beri. His conclusions were substantiated by experiments on human subjects, also carried out in the Malay States. The experiments with human subjects were quite similar in plan to Eijkmans procedures with chickens. The human experiments were carried out in an insane asylum and in railroad labor camps. Half of the subjects received pol- ished rice, and the other half received brown rice, from which the polishings had not been removed. In both cases, bet-i-beri appeared in the white rice groups, but not in the groups receiving brown rice. And, when the diets were reversed, the incidence of the disease also became reversed.
The rapidity with which chickens and pigeons develop polyneuritis on a diet of polished rice made them useful as test animals in studies for concentrating the anti-beri-beri vitamin, vitamin B,, from rice polishings. In 1926, B. C. P. Jan- sen and W. F. Donath, working in the laboratory formerly occupied by Eijkman, isolated vitamin Br as crystals from a water extract of rice bran. Ten years later, its chemical structure was discovered, and it was synthesized by Robert R. Williams (5) and J. K. Cline, and by H. Andersag and K. Westphal. Improved methods of synthesis made vitamin B, (thiamine) quite cheap.
An outstanding characteristic of thiamine is that it is present in the outer coats of grains, but is largely absent from refined white flour or polished rice. The availability and low cost of synthetic thiamine enabled it to be added to white (wheat) flour and polished rice as an enrichment, and this program has been of great importance in largely abolishing thiamine deficiency in many countries, including some countries where it had had devastating effects. Therefore Robert Williams was able to reach his objective of many years: to synthesize thiamine and promote its use in preventing beri-beri.
NICOTINIC ACID (NIACIN)
The third of the big three deficiency diseases caused by lack of water-soluble
880 THOMAS H. JUKES
vitamins is pellagra, a disease that was of widespread occurrence in certain coun- tries where corn (maize) was used as the main cereal grain. Regions in which pellagra was common were the southeastern United States and some European countries, especially in the Mediterranean area, associated with the extensive use of maize. Pellagra is characterized by dermatitis, diarrhea, and dementia.
The most frustrating events in the history of pellagra concern the chemist Casimir Funk. He was born in Poland in 1884 and received his Ph.D. degree in Bern, in 1904. Following this, he worked at the Pasteur Institute in Paris, then in Germany, and at the Lister Institute in London, where he received a D.Sc. degree in 1913. In 1912, he proposed the name vitamine for unidentified substances that were needed to prevent nutritional deficiency diseases, including beri-beri, scurvy, and pellagra. Indeed, he said that each of these diseases was caused by deficiency of a certain vitamine. This proposal and the coining of the name vitamine have been termed a stroke of genius. He was the first to state that pellagra was a nutritional deficiency disease. At that time, the general opinion seemed to be that pellagra was an infectious ailment. Funk then attempted to isolate the anti-bet+beri vitamine from yeast and rice bran. In this, he was un- successful, but he isolated nicotinic acid from these sources, and did not test it against pellagra. He said, however, that nicotinic acid had a beneficial effect when given in a mixture to his experimental rats together with water extracts of rice bran in tests against polyneuritis, caused by deficiency of what we now know as thiamine (1). Nicotinic acid was also isolated from yeast and rice bran in 1912 by Suzuki in Japan. Funks name is seldom mentioned in connection with pellagra, but, in 1937 when we published the announcement of the effect of nicotinic acid on patients with pellagra (6), I sent a copy of the article to Funk, who then lived in New York, and I wrote on the cover a dedication to him as the predictor of the anti-pellagra substance.
Nicotinic acid is one of several substances that have been isolated and de- scribed or identified without being tested for vitamin activity. They were not recognized as vitamins until they had been tested for their effect to prevent or cure nutritional deficiency diseases. Carotene, hexuronic acid, lactochrome (ribofla- vin), and phthiocol are other examples.
The outstanding pioneer in early studies of pellagra in the United States was Joseph Goldberger of the U.S. Public Health Service. He succeeded in proving that pellagra in the southern United States was not an infectious disease, but was caused by nutritional deficiency. Various heroic measures were employed by Goldberger and his associates in these studies, including many attempts to infect themselves by contact with pellagrins. This is described at some length in Paul de Kruifs book Hunger Fighters (7). After Goldbergers premature death in 1929, his work on pellagra was continued by Henry Sebrell. Eventually, it became gener- ally accepted that pellagra could be prevented or cured by good diets that included milk, meat, and by other protective foods such as yeast. The use of rats as experimental animals was attempted, but, in retrospect, deficiencies of ribo- flavin and of vitamin B, were produced in these experiments rather than any condition analogous to pellagra. In contrast, dogs developed a deficiency disease called black tongue when fed diets similar to those consumed by people with
HISTORICAL PERSPECTIVES 881
pellagra, and it was the cure of black tongue in dogs that eventually led to the identification of the anti-pellagra vitamin.
In 1936, Douglas Frost, then a graduate student at the University of Wisconsin, purchased some nicotinic acid from the Eastman Kodak Co. and endeavored to find a role for it in the nutrition of rats. Simultaneously, some of his colleagues were attempting to identify the anti-black tongue factor in experiments with dogs. Douglas Frost and Esmond Snell have both told me of an evening laboratory conference involving them and a graduate student, Robert Madden; a postdoc- toral fellow, D. Wayne Woolley, and a junior faculty member, Frank Strong. They decided to try feeding nicotinic acid to dogs with black tongue in the animal colony of the laboratory. The disease was cured quite dramatically, and the head of the project, Professor C. Elvehjem, returned from vacation to learn of the exciting result. This was in the summer of 1937 (8). Confirmation of these results soon followed, and it was soon found that nicotinic acid was indeed the anti- pellagra factor for human beings (6). It was also shown that pellagrins typically suffered from other deficiencies in addition to that of nicotinic acid. In 1938, Sebrell and Butler identified one of these deficiencies as that of riboflavin (9). Another investigator at the University of Wisconsin, Willard Krehl, made the surprising discovery that the amino acid tryptophan could substitute for nicotinic acid in the treatment of pellagra (10). Tryptophan is metabolized in the body to produce nicotinic acid. This helped to explain the association of pellagra with diets high in maize, because the principal protein of maize, zein, contains no tryptophan. Animal proteins, such as those in meat and milk, are good sources of tryptophan, in contrast to most plant proteins. The name nicotinic acid was considered to be unattractive, derived as it was from the word nicotine, be- cause nicotinic acid was originally produced in the laboratory by oxidation of nicotine with nitric acid. The name niacin was therefore introduced to popu- larize the new vitamin, and niacinamide replaced nicotinic acid amide. Ni- acinamide is widely used instead of niacin in vitamin preparations because it lacks the vasodilating effect of niacin. This rather dramatic flushing effect was first described by Fouts et al. in 1937 (6). Sebrell (11) has published a fascinating account of the early history of pellagra.
VITAMINS AND EVOLUTION
It is of interest to examine the vitamins from the standpoint of evolution. Now that an RNA world is considered to have preceded the present protein world, it has been proposed by several authors, including Joyce (9), that several coenzymes date as far back as the RNA world, perhaps 4 billion years ago. At that time, these coenzymes were derived from nucleic acid bases, especially adenine, which is in nicotinamide adenine dinucleotide (NAD), flavin adenine dinucleotide (FAD), and coenzyme A. These coenzymes continued to function in metabolic pathways, for electron and proton transfer and other purposes, when protein enzymes appeared. This appearance took place in an early anaerobic era, and, next, photosynthesis by cyanobacteria changed the atmosphere by introduction of oxygen and the environment became aerobic. Cyanobacteria became chloro- plasts, which produce carotenes. The animal kingdom became parasitic on the
882 THOMAS H. JUKES
plant kingdom because the green plants produced nutrients by photosynthesis. As is typical of parasites, the animals became lazy. Animals, including protozoa, discarded some metabolic pathways when they relied on food made by the green plants, or in some cases, by bacteria or yeasts. In consequence, animals do not produce the vitamins, and also about 8 of the 20 amino acids. These are the essential amino acids, obtained from plants or, in the case of carnivores, by predation on vegetarian animals.
B-Carotene in chloroplasts was used as the precursor of retinol to enable the evolution of vision by vertebrates. Thiamine, riboflavin, nicotinic acid, pyroxi- dine, pantothenic acid, biotin, and folic acid were synthesized by green plants, yeasts, and bacteria, and became vitamins that were needed in the diet of animals that could not make them. Vitamin B,, was discarded by green plants, with the sharp distinction that it is needed by Euglena, an algal protozoan. Vitamin B,* is made only by bacteria, and it is obtained by animals from intestinal bacteria, including by coprophagy (as in the well-known case of rabbits), from lactating ruminants, or by predation in the case of carnivores.
Vitamin D is actually a hormone produced by exposure of the skin to direct sunlight. It can be obtained by predation, especially on fish liver oils, and also from food materials (nonliving) that have been naturally irradiated, such as hay, or by artificial irradiation of 7-dehydrocholesterol or of ergosterol. Vitamin D is not needed if animals are in the sunlight for a short time each day, and, in con- sequence, it need be supplied only to human beings or domestic animals that live in buildings or in very gloomy climatic zones.
Vitamin E, an antioxidant, is obtained from plants. Vitamin K is obtained from plants or from bacteria. Vitamin C, is by far the most recent of the vitamins, because nearly all vertebrates, including most mammals, produce it biosyntheti- tally, and, of course, it is abundantly produced by green plants. The name vi- tamin F was once used for the essential unsaturated fatty acids, but this term has been dropped, probably because they are needed in larger amounts than the vitamins.
The most interesting development in evolution of vitamin dependence concerns ascorbic acid (vitamin C). The ability to synthesize ascorbic acid is not present in certain passerine birds, in fruit-eating bats, in guinea-pigs, and in Anthropoidea. We have postulated that these species lost this ability by a neutral evolutionary change that occurred sporadically by mutation (13). The loss was that of an enzyme system which converts D-glucurono lactone to ascorbic acid. The change was adopted in the genetic makeup of a few groups of birds and mammals that are widely scattered in phylogeny. Many herbivorous vertebrate species that con- sume diets high in ascorbic acid have retained the ability to synthesize it, so that carrying the enzyme system does not appear to impose a genetic load, and therefore no advantage has been gained by losing it.
I have described how many years of research were needed to overcome three nutritional diseases that occurred throughout the world. When human beings migrated from tropical and subtropical regions to the temperate zone, they lost
HISTORICAL PERSPECTIVES 883
their year-round supplies of vitamin C, and scurvy began to occur. The emergence of beri-bet-i had a mechanical basis; the introduction of milling, which prevented the rancidity of rice and wheat, also removed the essential vitamin B,. The cir- cumstance leading to the third deficiency disease was reliance on maize, without supplementing it with protective foods, such as meat, milk, and vegetables. Under conditions of poverty, the protective foods became expensive, and pellagra appeared (7, 11).
Synthetic chemistry, together with improvements in the diet and in education, largely overcame scurvy, beri-beri, and pellagra, but deficiencies of vitamins A, C, and folic acid still occur widely in economically disadvantaged populations, and this is a challenge to those who wish to improve public health. The brilliant prophesies of Casimir Funk, made in 1912, were fulfilled within 25 years. Today, his word vitamin is universally familiar.
The account of the discovery, identification and synthesis of the vitamins is the story of how human beings have overcome nutritional deficiencies that were imposed by cultural and economic disadvantages or just plain ignorance. These discoveries were a triumph of science and technology. Much of the research depended on the use of experimental animals: guinea-pigs, rats, dogs, monkeys, and chickens. Vitamins are now added to the diets of both animals and human beings.
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Co., 1938. 6. Fouts PJ, Helmer OM, Lepkovsky S, Jukes TH. Treatment of human pellagra with nicotinic acid.
Proc Sot Exp Biol Med 1937; 37:405-407. 7. De Kmif P. Hunger Fighters. New York: Harcourt, Brace, 1928. 8. Jukes TH. Dilworth Wayne Woolley. .I Nutr 1974; 104~509-511. 9. Sebrell WH, Butler RE. Riboflavin deficiency in man. A preliminary note. Public Health Rep
53~2282-2284. 10. Krehl WA, Teply LJ, Sarma PS, Elvehjem CA. Growth-retarding effect of corn in nicotinic
acid-low rations and its counteractions by tryptophan. Science 1945; 101:489-490. 11. Sebrell WH. History of pellagra. Fed Proc 1981; 40:152@-1522. 12. Joyce GF. RNA evolution and the origins of life. Nature (London) 1989; 338217-224. 13. Jukes TH, King JL. Evolutionary loss of ascorbic acid synthesizing ability. .I Hum EvoZk85-88.