The Nightmare of the Age of Exploration and the Birth of Vitamins: From the Miracle of Scurvy to Umetaro Suzuki's Contribution

During Vasco's expedition, on its voyage around the Cape of Good Hope and into the Indian Ocean, 60% of the crew contracted scurvy. According to a 1593 British record, over 10,000 people in the British Navy contracted scurvy in a single year. At the time, the cause of scurvy was unknown, and there was no cure; those afflicted eventually died from internal bleeding. Scurvy became one of the most feared diseases among sailors. However, miraculous cures for scurvy circulated among sailors, though few believed them. Among the various rumors, the most exciting was a medicine concocted by Native Americans. It was said that drinking this medicine could cure even the most seriously ill patients.

To prevent sailors suffering from scurvy from dying on board, those on the verge of death were sent to deserted islands. Starving and forced to eat wild grasses, the sailors miraculously recovered from scurvy after two or three days. British naval surgeon James Lind was intrigued by these tales. He investigated the medicines prepared by the Native Americans and discovered they contained pine needles. He concluded that components in plants might be effective in treating scurvy. He experimented with various plants and found that fruits and vegetables contained substances effective in treating scurvy.

Lemon juice was the most effective remedy. So, he selected 12 sailors on his ship and gave only 2 of them lemon juice daily. The 10 sailors who didn't drink lemon juice developed scurvy, while the 2 who did remained healthy. Linde reported this result to the British Navy. However, the British Naval Headquarters dismissed Linde's report. They ridiculed him, saying, "If lemon juice can cure scurvy, then you can build ships from leaves!" However, the famous British navigator Captain J. Cook (1728–1779) believed Linde's report.

He carried large quantities of lemons with him on his voyages, and as a result, none of his sailors contracted scurvy. It wasn't until the early 19th century that the British Navy mandated the supply of lemon juice to its sailors. This was 50 years after Linde had made the suggestion to Admiralty. In those 50 years, tens of thousands of British sailors died of scurvy. From then on, lemons were commonly used at sea to prevent or treat scurvy. However, at the time, it wasn't understood why lemons were so effective in preventing and treating scurvy. In the early 19th century, people believed that scurvy was caused by poisoning from harmful substances in food, and that lemons might "neutralize" these toxins.

In the latter half of the 19th century, with the discovery of Kochella and the advent of immunotherapy invented by Pasteur, humanity began a glorious period of fighting back against long-standing infectious diseases. This period was marked by the discovery of new pathogens and the active use of vaccines for disease prevention and treatment, a time of great advancements in bacteriology. Therefore, the view that scurvy was an infectious disease was prevalent at the time. It was not then possible to recognize that vitamin C in lemons was an essential component for the human body, and that a deficiency of vitamin C led to scurvy.

In the late 19th century, beriberi became prevalent in the Dutch East Indies. Those afflicted suffered from swollen feet, numbness in the lower body, difficulty breathing, and many even died. The Dutch government sent numerous scholars and officials to investigate the cause of the disease. The investigation concluded that "beriberi is an infectious disease caused by bacteria." After reaching this conclusion, the scholars returned to the Netherlands. However, one scholar named Eckmann remained, intending to further investigate the causative bacteria of beriberi. Unfortunately, he was unable to find the pathogen.

One day, he found a strange chicken in the hospital yard. The chicken's head was bent, and its claws trembled, just like someone suffering from beriberi. It turned out that this chicken had grown up eating the leftovers of beriberi patients. So, Eckerman decided to try and find the bacteria causing beriberi in this chicken. However, the hospital director was stingy and wouldn't allow the chicken to be fed polished rice, only cheap brown rice. Eckerman had no choice but to follow the director's orders and feed the chicken brown rice every day. After several days, he unexpectedly found that the chicken was cured.

Chickens that eat only polished rice get beriberi, while those that eat brown rice are cured of it. He wondered, "When rice is processed into polished rice, are some of its components lost? If this is true for chickens, is it also true for humans?" So Eckermann investigated the situation of prisoners in prisons. He found that in prisons where prisoners ate polished rice, nearly half of the inmates had beriberi, while no prisoners in prisons where prisoners ate brown rice had beriberi. It could be said that Eckermann was only one step away from discovering vitamin B₁, yet he became a prisoner of the then-prevalent theory of bacteria. His final conclusion was that rice bran contained a substance that was very effective in inhibiting beriberi bacteria.

In 1882, the Japanese warship "Ryujin" sailed to New Zealand. During the 272-day voyage, more than half of the 376 officers and men contracted beriberi, and 25 of them died. The then Chief Surgeon, Takagi Kanehiro (1849-1920), wondered if the beriberi in the Japanese navy, given the rarity of beriberi among foreign navies, was due to their rice diet. On a voyage in 1884, he decided to reduce rice and increase vegetables and protein intake to see the results. Following the same route, this time only 14 men contracted beriberi. Takagi Kanehiro concluded that beriberi was likely caused by insufficient protein intake.

After returning to Japan from his research with German chemist Fischer, Umetaro Suzuki (1874-1943) began studying rice protein. He believed that the poor health of the Japanese people might be due to a problem with the protein in rice. After painstaking research, in 1910 he finally succeeded in extracting a substance from rice bran. This substance was essential for animal growth; a deficiency of it could lead to beriberi. Suzuki named this substance vitamin B₁ (later known as glutamate). This was the earliest substantial discovery related to vitamins. Unfortunately, however, the results of this research were published internationally relatively late.

The internationally recognized first discoverer of vitamins is Fink. Fink extracted a substance from rice bran in 1911, which he named vitamin. Vitamin E was discovered in 1922 by Evans and Bishop et al. at the University of California. Around 1920, it was generally believed that feed sufficient for animal growth and health should also be sufficient for reproduction. However, Mendel et al. discovered through experiments that while rats fed only milk grew well and were in good health, they could not reproduce. This result led them to believe that milk lacked the nutrients necessary for reproduction.

Evans and his colleagues studied the effects of nutrition on the estrous cycle of rats. The feed they used to raise the rats was rich in protein, minerals, and vitamins. They found that this diet resulted in the rats, sometimes even the next generation, failing to reproduce. Later, they added fresh wheat germ, lettuce, and alfalfa sprouts to the feed, and the rats regained their reproductive function. Therefore, they concluded that these additives might contain some unknown physiologically active substance.

Because the chemical structures of vitamins were not yet fully understood at the time, they were named in the order of their discovery. The substance that effectively restored reproductive function was the fifth vitamin discovered and was named Vitamin E in 1923. Evans et al. named it tocopherol based on its effects and properties. In the first half of 1930, Evans et al. discovered that this substance was not a single component, but a mixture of components with varying degrees of physiological activity. They named the more active component α-tocopherol and the less active component β-tocopherol.

Subsequently, the even less active γ-tocopherol was discovered. By 1946, vitamin E-like substances had been successively discovered, with eight naturally occurring substances exhibiting vitamin E activity identified. The main function of vitamin E is to prevent lipid peroxidation in the body. Recent findings suggest that vitamin E may have anti-aging effects, thus attracting even more attention.