Scurvy doesn't just turn your skin yellow. 
 
 In fact, in the later stages of the disease, the skin turns black, often right before you die, horribly, from massive internal hemorrhaging near the brain or heart. 
 
 While in middle school health class, you probably learned that sailors of centuries past suffered scurvy when they didn't eat enough oranges. But what you didn't hear was that between 1500 and 1800, an estimated two million of them died from it! 
 
 "It was such a problem that ship owners and governments counted on a 50 percent death rate from scurvy for their sailors on any major voyage," science journalist Catherine Price wrote in her book Vitamania. "[A]ccording to historian Stephen Bown, scurvy was responsible for more deaths at sea than storms, shipwrecks, combat, and all other diseases combined." 
 
 British Commodore George Anson's celebrated voyage around the world may have earned him fame and fortune, but it also resulted in the deaths of 65% of his crew. 1,300 sailors, stationed across six ships, lost their lives, the vast majority of them to scurvy. Nice job, commodore. 
 
 Scurvy wasn't simply a recurring nuisance, it was an appalling scourge, one exacerbated by its gruesome symptoms. 
 
 "Scurvy starts with lethargy so intense that people once believed laziness was a cause, rather than a symptom, of the disease," Price wrote. "Your body feels weak. Your joints ache. Your arms and legs swell, and your skin bruises at the slightest touch. As the disease progresses, your gums become spongy and your breath fetid; your teeth loosen and internal hemorrhaging makes splotches on your skin. Old wounds open; mucous membranes bleed." 
 
 That's not even the worst of it. Two separate accounts -- one from a chaplain and the other from a surgeon -- describe how the gums engorge and grow over the teeth. If not cut off, the tissue may protrude from the mouth and start to decay. The dying tissue endowed sufferers with the worst possible breath imaginable. 
 
 The scope and severity of scurvy was remarkable, especially considering how easy it is to prevent and treat. Scurvy results from a deficiency of vitamin C, which is commonly found in citrus fruits, peppers, and a variety of other plant sources. As little as 10 milligrams of the vitamin per day -- one-fifth the amount found in a single orange -- administered over a week or so, can bring a scurvy sufferer back from the brink of death. 
 
 But back when scurvy was at its deadliest, humanity was unaware of the existence of vitamins. Ships on long overseas voyages were also ill equipped to store fresh fruits and vegetables. Moreover, cooks onboard didn't know that vitamin C is destroyed by heat, as well as cutting, and even exposure to air. But perhaps the biggest impediment to solving scurvy was a slow spread of information. Journals of ship physicians dating back to the 17th century reveal that a good few stumbled upon the healing powers of oranges, limes, lemons, and cabbage, but their discoveries never made it to common knowledge. 
 
 Scurvy's decline began in 1747, when James Lind demonstrated and publicized citrus' power to treat the disease. In the 19th century, scurvy dwindled at a healthy pace. Today, scurvy is mostly a defunct disease of the past, but citizens of underdeveloped countries -- particularly children -- are still susceptible. 
 
 (Image: CDC) 
 
 Source: Price, Catherine. Vitamania: Our Obsessive Quest For Nutritional Perfection. Penguin Press, 2015. The science and technology focused Alfred P. Sloan Foundation helped make this book possible. ||||| The emergence of scurvy Scurvy did not emerge as a problem for maritime explorers until vessels started penetrating the Indian and the Pacific Oceans. Vasco da Gama lost two thirds of his crew to the disease while making his way to India in 1499. In 1520 Magellan lost more than 80 per cent while crossing the Pacific. Two voyages made by Pedro de Quiros early in the 17th century resulted in huge mortality from a sickness Sir Richard Hawkins called, after his venture into the South Seas, 'the plague of the Sea, and the Spoyle of Mariners'. ... Magellan lost more than 80 per cent of his crew while crossing the Pacific. Scurvy came to public notice in Britain after Commodore George Anson led a squadron into the Pacific in the 1740s to raid Spanish shipping. He lost all but one of his six ships, and two thirds of the crews he shipped (700 survived out of an original complement of 2000), most of them to scurvy. Their symptoms were vividly described by Richard Walter, the chaplain who wrote up the official account of the voyage. Here were descriptions of its ghastly traces: skin black as ink, ulcers, difficult respiration, rictus of the limbs, teeth falling out and, perhaps most revolting of all, a strange plethora of gum tissue sprouting out of the mouth, which immediately rotted and lent the victim's breath an abominable odour. There were strange sensory and psychological effects too. Scurvy seems to have disarmed the sensory inhibitors that keep taste, smell and hearing under control and stop us from feeling too much. When sufferers got hold of the fruit they had been craving they swallowed it (said Walter) 'with emotions of the most voluptuous luxury'. The sound of a gunshot was enough to kill a man in the last stages of scurvy, while the smell of blossoms from the shore could cause him to cry out in agony. This susceptibility of the senses was accompanied by a disposition to cry at the slightest disappointment, and to yearn hopelessly and passionately for home. Now we know that scurvy was a cocktail of vitamin deficiencies, mainly of C and B, sometimes compounded by an overdose of A from eating seals' livers. Altogether these produced a breakdown in the cellular structure of the body, evident in the putrescence of the flesh and bones of sufferers, together with night blindness and personality disorders associated with pellagra. In the 18th century no one knew what caused scurvy, whose symptoms were so various it was sometimes mistaken for asthma, leprosy, syphilis, dysentery and madness. Top 
 
 Prevention Physicians speculated that it was owing to a salt diet, to a lack of oxygen in the body, to fat skimmed from the ships' boiling pans, to bad air, to thickening of the blood, to sugar, to melancholy; but no one knew for certain. People were aware that once victims were on shore they could be recovered by eating scurvy grass, wild celery, wood sorrel, nasturtiums, brooklime, Kerguelen cabbage (Pringlea antiscorbutica), cabbage trees and other esculent plants growing on the shores of distant islands. Fruit and palm wine were also esteemed to be fine remedies, and since 1753, when James Lind published A Treatise of the Scurvy, there was experimental proof that citrus had a rapid beneficial effect. Once on shore it was a superstition among sailors that the smell and the touch of the earth gave the surest cure. One of Anson's crew had his shipmates cut out a turf and put his mouth into the hole. Vitus Bering, the Danish navigator, died of scurvy half buried in the ground. No one had a remedy for scurvy at sea - however; the best on offer was a battery of prophylactic measures, including portable soup (a preparation of dried vegetables), malt, sauerkraut, concentrated fruit juice (rob), vinegar, mustard, molasses and beans. These were aimed at repelling any sign of scurvy from the outset, since it was impossible to control it, once it had gained a footing, other than by going ashore. ... it was impossible to control scurvy, once it had gained a footing, other than by going ashore ... All the British voyages of the Pacific undertaken in the 1760s - by Byron, Wallis, Carteret and Cook - were used to test these prophylactics. Wallis carried malt, sauerkraut, 'vinegar and mustard without limitation', 30 hundredweight of portable soup, and 180 Magellan jackets to protect the men against cold and damp. Under the direction of the 'Sick and Hurt and Victualling Boards of the Admiralty', Cook was supplied likewise with 40 bushels of malt, 1000lb of portable soup, vinegar, mustard, wheat, together with 'proper Quantities of sauer Kraut and Rob'. Like Wallis, Cook paid strict attention to airing and drying the lower decks, and keeping his men warm and well slept. Top 
 
 Scurvy takes its toll Cook had five cases of scurvy reported by his surgeon and no deaths from it. Wallis's men were dogged by the disease, three dying of it, and he himself appears to have been suffering from it when he came across Tahiti. Byron reports the 'dreadful havock' made among his crew by the disease, while Carteret records 31 men dead of scurvy, and his ship for the most part of his voyage a hospital. In his next two voyages Cook's good management, or luck, persisted, and no deaths from scurvy were reported. Since then he has been hailed as the conqueror of the sea's great plague. William Bowles wrote in his poem The Spirit of Discovery (1804): Smile, glowing Health! For now no more the wasted seaman sinks, With haggard eye and feeble frame diseased; No more with tortured longings for the sight Of fields and hillocks green, madly he calls. ... Cook was in no doubt that the principal cause of the health of his crews was owing to regular doses of malt ... Recently Christopher Lawrence has called Cook's regimen 'a representation and an endorsement of 18th-century social order'. For his own part, Cook was in no doubt that the principal cause of the health of his crews was owing to regular doses of malt, and woe betide the sailor who refused it! In a paper delivered to the Royal Society he said of malt, 'This is without doubt one of the best antiscorbutic [effective against scurvy] sea-medicines yet found out; and if given in time will, with proper attention to other things, I am persuaded, prevent the scurvy from making any great progress for a considerable time'. There were dissenting voices about this at the time, as there still are today. Gilbert Blane and Thomas Beddoes, highly esteemed authorities on scurvy in the 18th century, rightly doubted that there was any antiscorbutic virtue in malt. Thomas Trotter, another expert, thought sauerkraut and portable soup were 'mere placebo'. They stated what Lind had already experimentally deduced - that fresh vegetables and citrus juice are the only substantial sources of vitamin C. But although 'rob' was carried on board Cook's ships, it had been boiled to reduce it, and in the process all its vitamin C (ascorbic acid) had been lost. Top 
 
 Cook's men suffer It turns out that Cook's prohibition against the fat from the boiling pans was the only truly antiscorbutic measure he took, for hot salt fat coming into contact with copper acquired a substance that irritates the gut and prevents its absorption of vitamins. James Watt has pointed this out in several articles, together with the plausible conjecture that an infestation of worms caused a similar effect in Cook's own body, precipitating a deficiency of vitamin B that might have been responsible for his odd behaviour in Hawaii shortly before his death. There is no doubt that many people suffered from scurvy on Cook's ships. There is no doubt that many people suffered from scurvy on Cook's ships. On the second voyage William Wales, the astronomer, and Johann Reinhold Forster, the naturalist, both give descriptions of their symptoms, chiefly their growing melancholy and sense of isolation. On the first, Joseph Banks records that once the Endeavour was in the Arafura Sea everyone - except Cook, Solander and himself - were suffering from homesickness, 'the longing for home which the Physicians ... esteem a disease under the name of Nostalgia.' Thomas Trotter was to characterise the symptoms 20 years later as 'scorbutic Nostalgia', a condition to which Banks himself soon succumbed, when he thought of the explorer William Dampier in these same seas, and confessed, 'this thought made home recur to my mind stronger than it had done throughout the whole voyage'. When they landed at Savu, Banks reported that there were many people sick on board. The deaths at Batavia of Tupaia, the priest from the island of Raiatea, and Charles Green, the astronomer, have usually been ascribed to the dysentery that killed 30 of the Endeavour's crew at the end of the voyage. Beaglehole suggests, however, that it was not dysentery that put an end to Tupaia's life and Cook himself was adamant that his death was owing to 'the long want of a vegetable diet which he had all his life before been used to, and brought upon him all the disorders attending a sea life.' As for Green, 'he had long been in a bad state of hilth, which he took no care to repair but on the contrary lived in such a manner as greatly promoted the disorders he had had long upon him'. Top 
 
 Cook's record Cook was referring to the fact that Tupaia refused malt, portable soup and all the other remedies against scurvy, and that Green's addiction to drink was precipitating scorbutic symptoms. However, Tupaia, Green and a crew member named Hicks had been diagnosed at Batavia as the three people suffering from complaints 'occasioned by long continuance at sea', which makes it look as if perhaps Cook's record is not as clean in this respect as has sometimes been thought, and he did lose two of his men to scurvy. That was not his reputation, however, and based on his example no commander wanted scurvy on his ship. When James Morrison reported that scurvy appeared on the Bounty on the run between the Cape of Good Hope and Tahiti, Captain Bligh wrote in the margin of his manuscript 'Captain Bligh never had a symptom of Scurvy in any ship he commanded', and Vancouver was dismayed when he found it on his vessel, Discovery, while he was mapping the north east coastline of America: 'To my utter astonishment and surprise, I was given to understand from Mr Menzies that the sea scurvy had made its appearance amongst some of the crew.' Clearly it was greeted with the same shock and incredulity as headlice today. In naval logs of the later 18th century, scurvy is scarcely mentioned, fluxes and cholera being far the most common complaints. But Leonard Gillespie, a naval surgeon, had it reported to him that scurvy was still common on the India station, and that in 1781 HMS Egmont lost a third of her crew to the disease, on a return journey from Jamaica. Thus it has always been hard to say anything authoritative about scurvy, or to trust the testimony of its victims, who are afflicted by emotions so powerful that they lose the virtue of dispassionate neutrality that has been understood to distinguish the minds of explorers and navigators during the Enlightenment. Hence William Wales's terse yet strangely querulous entry in his Resolution journal: 'Brewed Wort [malt] for some of the People who began to have symptoms of the Scurvy. I suppose I shall be believed when I say that I am unhappy in being one of them'. About scurvy so much is to be supposed, so little known for sure. Top 
 
 Find out more Read on The Ship - Retracing Cook's Endeavour Voyage by Simon Baker (BBC Worldwide, 2002) The Journals of Captain Cook, edited by Philip Edwards (Penguin, 1999) The Wooden World: An Anatomy of the Georgian Navy by NAM Rodger (many editions since 1986, including WW Norton & Co, 1996). Top ||||| WELLINGTON, New Zealand (AP) — The story of a Salvadoran fisherman who says he survived more than a year adrift on the Pacific Ocean raises many medical questions. The Associated Press spoke with Claude Piantadosi, a professor of medicine at Duke University and author of the book "The Biology of Human Survival," to find out what is physically possible and for his view on the tale of Jose Salvador Alvarenga. This is an edited version of the interview: 
 
 In this Monday, Feb. 3, 2014 photo provided by the Marshall Islands Foreign Affairs Department, a man identifying himself as 37-year-old Jose Salvador Alvarenga sits on a couch in Majuro in the Marshall... (Associated Press) 
 
 In this Monday, Feb. 3, 2014 photo provided by the Marshall Islands Foreign Affairs Department, a man identifying himself as 37-year-old Jose Salvador Alvarenga sits on a couch in Majuro in the Marshall... (Associated Press) 
 
 Q: How long can a human survive without any water, or without any food? 
 
 A: The average is about 100 hours (approximately four days) without water and about five or six weeks without food. You can survive much longer with just a little food, although you'll lose weight and run into vitamin deficiency problems. So it would have been vital for Alvarenga to have collected both food and water during his journey. The Pacific's regular squalls would have provided some rainwater that he could have scooped from the bottom of his boat. 
 
 Q: How important is shade? 
 
 A: Absolutely critical. You get significantly warmer in direct sunlight and sweat more. The pictures of the boat show a fiberglass box in the middle which he could have sheltered in, and any type of canvas would have helped keep him out of the sun. 
 
 Q: Alvarenga described catching turtles, fish and birds with his hands and eating them. Is that plausible? 
 
 A: Over time, the underside of the boat would have become its own ecosystem as barnacles, seaweed and jellyfish collected there, which in turn attracts other creatures. How often can you grab a turtle or catch a fish with your bare hands? I don't know. Bird blood is no more salty than human blood, so would have provided some hydration. 
 
 Q: Without fruit and vegetables, wouldn't he have developed scurvy? 
 
 A: Actually, unlike humans, birds and turtles make their own vitamin C, so fresh meat from those creatures, especially the livers, would provide sufficient vitamin C to prevent scurvy. British sailors used to get scurvy because they ate preserved meat which had oxidized and lost its vitamin C. 
 
 Q: Wouldn't he get skin sores from all that water? 
 
 A: He'd need to keep mopping himself off and stay dry to avoid that. People on life rafts, or say a piece of floating wood, can develop real problems with macerated skin. Staying out of the water is a huge advantage. 
 
 Q: There's some suggestion that Alvarenga was a large man before he left. Would being overweight provide an advantage? 
 
 A: It would be a significant advantage. He could live off his own body fat and muscle for a long time, so long as he was able to get some water, vitamins, micronutrients and a little protein. 
 
 Q: Didn't he look too healthy, even a little bloated, when he arrived? 
 
 A: The appearances of malnutrition can manifest differently depending on how short you are on calories or protein. Some underfed children in Africa look like stick figures, others get swollen. It's only in end stage starvation that people get that really emaciated appearance. 
 
 Q: Alvarenga seemed to give confused and contradictory answers to authorities. What kind of psychological effects would such a journey have? 
 
 A: I'm not an expert in psychiatry, but we all have the feature of resilience. It can be trained or even learned on the fly. For instance, soldiers learn to deal with combat horrors. Presumably he was out on the ocean every day as a fisherman before he went missing, so he would have been familiar with the environment and with adapting his behavior to the elements. 
 
 If he had nutritional deficiencies, he may have developed some dementia or other syndromes which compromised his mental state. I'm not surprised that some of the answers he gave were a bit off and he wasn't able to remember things. 
 
 Q: How long would it take to recover from a voyage like this? 
 
 A: Hydration can be restored in just a day or two. Re-feeding can be tricky after a long period of starvation, as the body can lose the ability to absorb nutrients. Muscle rehabilitation and physical therapy can take several weeks. 
 
 Q: Bottom line — is Alvarenga's story plausible? 
 
 A: Yes. It's unusual to say the least. But reports out of Mexico indicate he did go missing in late 2012. As we have gotten more information, it's probably likely that he did survive at sea for 13 months.
– A ship's chaplain in the 1740s wrote of sailors' gums that would grow out of control until they protruded from the mouth and rotted away, leaving a horrific case of bad breath, the BBC reports. So it turns out that not only was scurvy once incredibly dangerous, it was also super gross. Real Clear Science reports that approximately 2 million sailors died from scurvy, which is caused by a lack of vitamin C, between 1500 and 1800. During his voyage across the Pacific, Magellan lost 80% of his crew to the disease called "the plague of the sea," according to the BBC. One historian says scurvy killed more sailors than battle, storms, shipwrecks, and other diseases combined. And, it wasn't a pleasant way to go, either. Scurvy starts with lethargy before causing achy joints, swollen limbs, and loose teeth, according to Real Clear Science. From there, sufferers get swollen gums, bad breath, and bruising. The skin turns yellow, then black, just before sufferers die from internal hemorrhaging. The tragic part is scurvy is ridiculously easy to cure. Real Clear Science reports someone on the brink of death from the disease could be saved by eating one-fifth of an orange every day for a week. Alas, doctors of the time didn't know what vitamins were, and ships weren't exactly built to store fresh fruit. The disease is mostly gone now, but a post at Phys.org notes that NASA scientists are using the lessons learned to ensure astronauts get the vitamins they need to stay healthy in space. (Is it possible kids are getting too many vitamins?)