Why Don't Governments Listen to Scientists? 1700s Edition

James Lind is usually credited for conducting the first prospective clinical trial, in 1747.

He had 12 patients: all sailors suffering from scurvy on a British Royal Navy ship. He tested 6 potential remedies – one on each pair of sailors – and then recorded what happened. Ten unlucky patients continued to suffer from the disease. But two patients – the two who had lemons and oranges – recovered quickly.

Five years later, Lind published his findings in a comprehensive book on scurvy. The British government, however, didn't take action on Lind's findings until 1795 – over forty years later – when they finally required a ration of lemon extract to every sailor headed to international waters.

This is supposed to be a story of bureaucratic obstinacy in the face of clear and convincing evidence, like many others we could mention. But the real story is far more interesting.

First of all, Lind's experiment was far from clear and convincing. It certainly didn't convince him. In his 450-page tome, he only devoted four pages to the experiment. He believed scurvy had a variety of causes. This was not an unusual assumption for the time – doctors believed that most diseases involved multiple interacting forces. Lind also, however, proposed a variety of potential solutions – a citrus-based extract (of some sort) was just one thing to do. What was a policy-maker supposed to do after reading 400 pages of, "maybe this, maybe that"?

A second complication is the interaction between expert and lay knowledge communities. By the mid-1700s, scurvy had been a consistent problem for sailors for at least two centuries. It was a common, horrific, and distinct disease. Through experience, sailors learned that citrus fruits (and fresh produce more generally) tended to both prevent and cure the disease. Stories of captains calling for citrus fruits when their men were suffering from scurvy are legion. Sailors already knew that citrus fruits and fresh vegetables could cure scurvy.

The fundamental problem was how to transport citrus fruits (or citrus extract) aboard ships that were at sea for months at a time. The Spanish had a policy in place (long before the English) for providing citrus extract to their sailors and had developed a couple of methods for bottling citrus extract. Sometimes this extract worked and sometimes it didn't, and no one could explain why. Much later, scientists would discover that vitamin C was the key ingredient for curing scurvy (and lack of vitamin C was the cause). Some extraction methods, which required boiling the fruit also destroyed the vitamin C, making it essentially useless.

In fact, Lind proposed just such an extract. If the Royal Navy had produced massive quantities of his recipe, it wouldn't have worked at all.

It wasn't Lind who, through his experiment, discovered that citrus fruits could cure scurvy; sailors had known that for a couple of hundred years. And it wasn't Lind who developed a practical solution to the underlying problem: making citrus fruits available on long voyages. That would await future work

Lind did do something remarkable – that is, if he actually conducted the study he reported. There's absolutely no corroborating evidence that he did so and the ship's records contradict his own account. But even as a thought experiment, it's something.

But did the British government do something wrong in this case? It's unclear. What probably should have happened is systematic experiments – of the kind Lind described – of the proposed extracts with a closer scrutiny of the manufacturing process. But even countries with (seemingly) more forward-thinking policies, like the Spanish, didn't do this. As Lind's story attests, no one really appreciated the power of clinical trials or how to conduct these studies in a useful way.

A different British doctor's discoveries about the cause of cholera is probably a better example of government inaction. But that's for another post.

REFERENCES

Many people have written about this story, but the best article I found on this whole saga is below.

Baron, J. H. (2009). Sailors’ scurvy before and after James Lind—A reassessment. Nutrition Reviews, 67(6), 315–332. https://doi.org/10.1111/j.1753-4887.2009.00205.x

Lind's book is: Lind, J. (1757). A Treatise on the Scurvy. A. Millar.