In honour of International Talk Like A Pirate Day (ITLAPD) I thought I would tackle the pirate's biggest concern (after other pirates, official Navies, reefs or anything else that was part of the pirate lifestyle), scurvy.

Pirates

Look out for a pirate march near you! Credit: leshoward

ResearchBlogging.orgScurvy is caused by a deficiency in vitamin C which humans and other primates receive by consuming food, particularly citrus fruits. But it turns out scurvy wouldn’t be a problem if not for one single mutated gene which, if it was still in tip top condition, would allow us to synthesise our own vitamin C, like every other friggin thing on this planet.

Humans cannot synthesise vitamin C as the gene for the enzyme L-gulonolactone oxidase (abbreviated to GULO, why do I think that is adorable?) is mutated. This enzyme is the last in a four step process other animals and plants use to convert glucose to vitamin C. Lucky for us then that we can consume and maintain a high level of it very easily, in fact most monkey species (including us) regularly take in up to 10 to 20 times the daily requirement.

Maintaining vitamin C levels is very important because it is considered to be an essential nutrient for growth and development. Vitamin C, or ascorbate (or ascorbic acid depending on how pedantic you are), is a powerful antioxidant and enzymatic co-factor (some enzymes need the support of another product, ascorbate helps at least 8 needy enzymes) and is fundamental to collagen synthesis, which becomes important later.

Vitamin C deficiency or scurvy, picked up its association with pirates due to the time spent at sea preventing them from maintaining a supply of fresh food, particularly fruits and vegetables. Pirate cuisine was less than appetising with common foods including thrice cooked breads (called hard tack or ship biscuits), salted pork or beef (made by boiling the meat in seawater), fish (but less often than you would think, not a lot of time to fish on a pirate ship) and dried staples like rice. If they could land the pirates would hunt for fresh fruits and vegetable as well as meat but food can only stay fresh for so long.

As the fresh supplies ran out, scurvy would set in. First signs of scurvy manifest as lethargy and malaise, which could easily been seen by others as laziness on a working pirate ship so many probably ignored the early signs of disease. After a couple of months without vitamin C your bones and muscles start to hurt and you also start to suffer chronic shortness of breath.

Then things start to get real.

Doctor Tom Saves The Day!

Serious doctor being serious. Credit: aeu04117

Prolonged vitamin C deficiency will see your skin change in texture and get rougher, you will bruise very easily and begin to develop minor skin haemorrhages called petechia. Your gums will begin to break down, and as they do, your teeth will loosen and begin to fall out. Cuts will not heal, at all, and on top of all that you can begin to change emotionally and psychologically.

Eventually, as you stop being able to produce adequate lubrication for your mouth, throat and eyes you will go into liver failure as your liver begins to liquefy inside your body. Your blood vessels will become very leaky resulting in generalised edemas (fluid deposition into the tissues). At the very end your brain will begin to liquefy as you begin to fever and convulse and finally, mercifully, death.

The liquefaction and loosening of your insides is caused by your inability to produce collagen in the absence of GUDO’s activity and vitamin C. A good guide to how important collagen is that it makes up approx 30% of your protein and, surprise surprise, is found sticking things together throughout the body. Collagen is a component of an important (and I just found out, unique to animals) space in your body called the extracellular matrix. Unlike plants, for example, where each cell is stack on other cells animal cells are suspended in this matrix allowing for better flexibility of the organisms and protection of the cells themselves. Collagen's roll is to stick things together but also provide the matrix with tension and flexibility allowing it to resist shearing forces.

Collagen is also the major component of connective tissues like tendons and ligaments giving them more elastic capabilities which, you know, allows your muscle to connect to bones and giving you a functioning lever system with which to move your endoskeleton around. It's important stuff is what I'm trying to say. Certainly not something you want to run out of.

While commonly associated with pirates and other diseases in history books scurvy still persists today, but often at a sub-clinical level. Studies have repeatedly shown that 10 – 15% of the population are technically deficient in vitamin C. So while you celebrate International Talk Like A Pirate Day today, perhaps do so while chowing down on an orange (or perhaps one of the 8 things containing more vit C than oranges).

References

McKenna KE, & Dawson JF (1993). Scurvy occurring in a teenager. Clinical and experimental dermatology, 18 (1), 75-7 PMID: 8440062

Velandia B, Centor RM, McConnell V, & Shah M (2008). Scurvy is still present in developed countries. Journal of general internal medicine, 23 (8), 1281-4 PMID: 18459013