Scurvy: Why it Took So Long

If the 17th century is seen as the Age of the Scientific Revolution, the 18th marked the Age of Discovery. The ships of many nations were now travelling across the world for commerce, colonization and piracy. They were fitted with cannons to protect them against their enemies and to allow them to attack rich foreign ships laden with treasure. The cannons required a large complement of men in addition to the crew that sailed the ship. Often the ships would be at sea for months at a time without touching land and the provisioning for the very large crew was difficult. Hard Tack, fresh water and occasional bits of stew was the basic ration for most regular seamen. Scurvy was the result and without treatment it led to a horrible death.

The primary lesions of scurvy relate to bleeding and swelling and inflammation of soft tissues and bone. Wounds don’t heal because you can’t make collagen. Bleeding occurs into the skin around the roots of all your hairs, which later fall out. Swollen gums bleed, the jaw bone softens, and eventually your teeth fall out. Hemorrhagic spots develop in your eyelid linings. There’s painful bleeding into your joints, and into the surface membrane of bones, causing crippling pain, and eventually spontaneous breakage of bones. Eventually you’re coughing up blood and possibly asphyxiating. Bleeding develops in the intestines, leading to black, and then bloody, horrifically foul smelling stools. Anemia, weakness. Emotional liability. Bleeding into the sack around your heart so your heart can’t fill with blood and pump. Bleeding around the brain, compressing it, causing headache, vomiting, eventually coma and death as your brainstem is crushed as your swollen brain pushes itself down into the spinal canal. Perhaps your spirit hovers overhead to watch your body committed to the deep.

The situation did not improve between the first publication of Lind’s Treatise and its third and final edition in 1772. Deaths due to scurvy and other diseases far exceeded the number of battlefield deaths during the Seven Years War (1756-1763). Once more the pressure for a cure increased, and sea trials continued without any clear success.

James CookJames Cook (1728-1779)

It was during this period that Captain James Cook organized his first expedition to circumnavigate the world in 1778. He demanded and received every contemporary support for the control of scurvy: ample supplies of Lind’s concentrated juice, large stores of fresh and preserved fruits and vegetables, and a careful selection of crew. (We know that on some of the other voyages, crew members were often selected from the poorest and least healthy parts of the population and at time forcibly brought on board ship.) Cook stopped as frequently as he could to “refresh” the ship and provide the men with fresh food and water. The result was the first truly successful voyage of discovery in health terms: no one died of scurvy, although the disease did occur when there were particularly long stretches away from shore. Cook made his reputation and received the Copley medal from The Royal Society for his success in staving off the disease (Bown, 2003:166). The Copley medal was then, and remains, a prestigious award for outstanding achievements in research in any branch of science.

James Pringle

John Pringle (1707-1782)

Cook’s success was followed by intense scientific wrangling. Rivalrous explanations of Cook’s success were led by Sir John Pringle (1707-82), the then head of the Royal Society. Pringle reviewed the surgeon’s records, and with a strong bias concluded that “sweet-wort” (unfermented beer) was the most effective preventive of scurvy. This turned out to be a major obstacle to the Navy’s acceptance of other solutions, and became the treatment of choice for a number of years, though it was of little value (Carpenter, 1986:17).

The scientific research establishment from Pringle’s time to the early 20th century hindered rather than helped the prevention of scurvy. Researchers and scientists, as well as clinical practitioners transferred successful solutions from one problem area to another: if sweet-wort helps with one problem of digestion, we should try it for scurvy, which appears also to be the same kind of problem. These physicians and scientists were often so committed to their settled explanations and frameworks that they continued to press for wrong-headed solutions in the face of massive evidence to the contrary. The greater their authority, the more resistant they seemed to be to new ideas. Often their intransigence was positively harmful.

Pringle was himself, not only President of the Royal Society, but a Copley medalist. He associated scurvy with rotten foods and believed in giving sailors foods such as sweet-wort. This unfermented beer was supposed to ferment in the stomach and correct the problem. Pringle was not alone in putting obstacles in the way of a scientific solution to the problem of scurvy. Later, other figures such as Sir Robert Christison (1797-1882) President, British Medical Association and physician to Queen Victoria, Jean-Antoine Villemin (1827-92) of the French Academy of Medicine, William A. Hammond (1828–1900) U.S. Surgeon General, and even Lord Lister (1827–1912) advocated dramatically false or misleading views about scurvy (Carpenter, 1986). This was largely because they did not understand the nature of a deficiency disease like scurvy.

Sir_Gilbert_Blane_by_Martin_Archer_Shee

Sir Gilbert Blane (1749-1834)

In the face of the medical establishment, progress could still be made on the policy front. Gilbert Blane, a physician from an upper class family, joined the navy in 1781 as Physician to the Fleet. From this position he had privileged access to the Admiral. After a short time he wrote that scurvy “may be infallibly prevented or cured by fresh vegetables and fruit, particularly oranges, lemons or limes” (Carpenter, 1986:92). His early letters to the Admiralty did not overcome the obstacle raised by the superior scientific authority of Pringle. However, he persevered, and in 1793 he instituted a test on one ship with the help of a friendly Admiral. Each man received two-thirds of an ounce of lemon juice mixed into the daily ration of grog. The ship took 23 weeks to reach India without touching land. Several men showed some symptoms of scurvy, but those soon disappeared after an increased dose of lemon juice. By the time the ship reached Madras, no one was affected by the disease.

In 1795, soon after Blane became a Commissioner on the Board of the Sick and Wounded Sailors, the Board recommended a daily allowance of three quarters of an ounce of lemon juice as part of the daily ration. After this date, the incidence of scurvy dropped very quickly. Just as the poor health of sailors due to scurvy was thought by some historians to be a factor in the British loss during the American Revolution, their good health after the elimination of scurvy was considered to be a major factor in the British maritime victories during the Napoleonic Wars (Porter, 2002).

The puzzle about the application of controlled trial results to policy has a very simple solution. It is quite clear with a close reading of Lind’s text. After he describes his clinical trial Lind declares the efficacy of oranges and lemons in the treatment of scurvy but,

As oranges and lemons are liable to spoil, and cannot be procured at every port, nor at all seasons in equal plenty and it may be inconvenient to take on board such large quantities as are necessary in ships for their preservation from this and other diseases the next thing to be proposed is the method of preserving their virtues entire for years in a convenient and small bulk. It is done in the following easy manner. [Lind, 1753 #67, Pg. 156.]

And our heart stops as Lind goes on to describe in great detail a process of heating the juice in a glazed earthen basin to almost boiling to allow the water to evaporate and produce a thick syrup (called  a “rob”) that can be reconstituted at sea. In this way the “virtues of twelve dozen of lemons or oranges may be put into a quart-bottle, and preserved for several years.” [Lind, 1753 #67, Pg. 157.]

We now know that boiling citrus juice for many hours severely reduces the amount of Vitamin C in the resulting syrup, and the reconstituted juice significantly dilutes whatever is left. It would not, and indeed did not prevent scurvy. But this “rob” rather than fresh oranges and lemons was Lind’s clear recommendation in his book. Moreover there is good evidence that the rob was used repeatedly with little good effect.

We can conclude that even though Lind believed fresh orange juice was a cure for scurvy, Lind was justified in believing that fresh orange juice was a cure for scurvy because of the trial. And it was true that fresh orange juice was a cure for scurvy. However we cannot conclude that Lind knew that fresh orange juice was the cure for scurvy because he also believed that the potency of the cure would be maintained if he boiled the juice down to a syrup or “rob.” (This is a real life example of a famous philosophical counterexample to the justified true belief model of knowledge that was first presented by Edmund Gettier in the Journal Analysis in 1963.)

Throughout the rest of his life Lind did not understand the outcome of his experiment. In later years when he became an academic physician and the successful head of the first sailors’ hospital at Haslam, he continued to try a whole range of other cures for scurvy with no success.

As patients we have learned to our dismay that there are many other cases where the conclusions of controlled trials turn out to be either ineffective or positively harmful, often because some aspects of the effect of a trial are not properly understood. This is not necessarily due to negligence, but to an inherent limitation of such trials in particular and to the justified true belief model of knowledge in general. Lind’s failure to see the importance of freshness in the juice is but the first example of this limitation and it accompanies the very first trial.

Of course there can be other parts of trials that are not in fact controlled and can have serious impact on the meaning of the results. One of my patient colleagues was asked to bring the patient’s perspective to the design of a particular controlled drug trial of an anti-depressant. The trial made sure that patients were not taking any prescription drugs that might interfere with the drug being studied. My colleague asked if they made sure that the patients had not also used herbal remedies like St. Johns wort that might have an effect (as many people have done for millennia.) In the trial they had ignored the effects of all herbal remedies and only excluded other prescription drugs. If my colleague was right, they could no longer claim that the results came only from the intervention that they had made. Often it is not clear what must be controlled in the various arms of a trial. We know, for example, that many drugs prescribed for older people or pregnant women are not tested on them, with occasionally disastrous consequences.

There is a growing struggle with some opposition from pharmaceutical companies to understand more vigilantly the limits of the results of controlled trials and also to monitor patients more thoroughly after they take new medications because of the risk of hitherto unknown side effects on their particular cohort. This kind of uncertainty about how to apply the results of trials to individual patients is a useful conclusion. We must be especially vigilant in prescribing drugs for the growing number of patients who will be long term users of drugs to control the effects of chronic diseases.

Outbreaks of scurvy recurred in the 19th century. For example there were outbreaks in France where scientifically developed infant formula was substituted for mother’s milk and in the Royal Navy itself when the fresh citrus juice was replaced with an adulterated version of lime juice.

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s