The Real Curse of The Black Pearl: A Retrodiagnosis

Many of our people died from [scurvy] every day, and we saw the bodies thrown into the sea constantly, three or four at a time. For the most part they died without aid given to them, expiring behind some case or chest, their eyes and the soles of their feet gnawed away by rats.

~16th century English sea surgeon

Pondering the effects of a poor diet is an awesome and terrible thing. Consider for a moment the fictitious Pirates of the Caribbean.

The dashing image of Captain Jack Sparrow was a far cry from the haggard, infirm figure of a real-life sailor in the 18th century. The hardships of sea life knew no bias: Warfare, shipwreck, injury, and drowning killed thousands. None of those threats, however, were responsible for as many deaths as the dreaded disease scurvy.

Scurvy is a condition characterized by fatigue, bleeding gums and skin, fragile bones, and muscle and joint pain. The body of a person with scurvy begins to break down and rot while they’re still alive. They become like a dead man walking.

Nearly 2 million sailors died from scurvy between the 15th and 18th centuries. During the Seven Years War, from 1756 to 1763, scurvy likely claimed the lives of nearly three-fourths of Great Britain’s Royal Navy – more than 133,000 men. Loss of life was only one of scurvy’s threats to the Navy. A little more than a decade earlier, mutiny ensued after the East India Company ship The Wager, her crew decimated and demoralized by nutritional deficits like scurvy, wrecked on the Patagonian archipelago.

Near the end of the 18th century, however, the discovery that citrus fruits could prevent or cure the disease prompted the Royal Navy to implement a prevention program that included a daily ration of lemon juice, eradicating the illness. The source of the juice’s health-giving effects was ascorbic acid, later known as vitamin C.

Vitamin C serves as a sort of molecular martyr. It donates electrons to other molecules in the human body to prevent oxidation from occurring – earning vitamin C the moniker “antioxidant” – and, in turn, undergoes oxidation itself. Vitamin C sacrifices itself this way in many reactions in the body, including those that produce key structural and chemical components like collagen, carnitine, and norepinephrine. The complications associated with the absence or deficiency of these components provide a framework for understanding the true curse of the Black Pearl.

A toothless grin

Collagen is a structural protein found in skin, bones, tendons, and cartilage. Vitamin C is involved in nearly every step of collagen formation, yielding a highly resilient triple-braided molecule, essential to every tissue in the body. So, the toothless image of Captain Barbossa’s crew was pretty accurate – without adequate vitamin C, collagen’s strength and rigidity fails, and the teeth are among the first to jump ship.

Night stalkers

Carnitine, a compound produced in the liver, facilitates fat metabolism. Without vitamin C for carnitine synthesis, fats can’t be transported into the cellular machinery where they get processed. This can cause hepatic encephalopathy, a condition where ammonia builds up in the bloodstream, resulting in dulled, even psychotic, thinking. Carnitine deficiency can also induce a reversal of day-night behavior, driving sleepiness during the day and wakefulness at night, perhaps explaining the proclivity of the Black Pearl’s crew for nocturnal activities.

A rolling stone

Normal brain function relies on norepinephrine, a type of neurotransmitter. The chemical reaction that produces norepinephrine starts when vitamin C binds to another brain chemical, dopamine, and converts it to norepinephrine. A person with low levels of norepinephrine in their brain might experience depression, mood swings, and other psychiatric symptoms – such as the Keith Richards-like behavior of Captain Sparrow following his exile on a remote, ostensibly citrus-free island.

Rewriting medical history (or a Hollywood movie script) is problematic without a proper physical exam, but many of the symptoms manifested by Captain Jack and his scabby cohorts point to one conclusion.

Retrodiagnosis: hypovitaminosis C (scurvy).



Brown, S., Scurvy: How a Surgeon, a Mariner, and a Gentlemen Solved the Greatest Medical Mystery of the Age of Sail, St. Martin’s Press, New York 2003.

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Thomas, D. P., Sailors, scurvy and science. J R Soc Med 1997, 90, 50-54.

Levine, M., Rumsey, S., Wang, Y., Park, J., Kwon, O., Xu, W., Amano, N., in: Ziegler, E. E., Filer, L.J. (Ed.), Present Knowledge in Nutrition, ILSI Press, Washington 1996, pp. 146-159.

Amat di San Filippo, C., Taylor, M. R., Mestroni, L., Botto, L. D., Longo, N., Cardiomyopathy and carnitine deficiency. Mol Genet Metab 2008, 94, 162-166.

Rebouche, C. J., in: Shils, M. E., Olson, J.A., Shike, M., Ross, A.C. (Ed.), Nutrition in Health and Disease, Williams & Wilkins, Baltimore 1999, pp. 505-512.

Carr, A. C., Frei, B., Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. Am J Clin Nutr 1999, 69, 1086-1107.



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