I tracked the claim back to Wikipedia and from there to this article.
Scurvy killed more than two million sailors between the time of Columbus’s transatlantic voyage and the rise of steam engines in the mid-19th century. The problem was so common that shipowners and governments assumed a 50% death rate from scurvy for their sailors on any major voyage.
Searching more broadly turned up this, which at least has a few claims we can check easily.
It has been estimated the disease killed more than 2 million sailors between the 16th and 18th centuries. On a lengthy voyage, the loss of half the crew was common, although in extreme cases it could be much worse. Vasco da Gama lost 116 of 170 men on his first voyage to India in 1499, almost all to scurvy. In 1744, Commodore George Anson returned from a four-year circumnavigation with only 188 of the 1,854 men he had departed with, most losses because of scurvy. Midshipman (and future admiral) Augustus Keppel was one of the lucky survivors—at the cost of all his hair and teeth.
1) Vasco’s mission lost 116⁄170 people.
1) Wikipedia says his mission began on 08/29/1498 and ended on 01/07/1499 (so about 3 months). Half died, many of the rest had scurvy.
2) This site says only 54 of Vasco’s crew “returned with him”; presumably the discrepancy in deaths here is because this site is counting the deaths incurred on both leaving and coming back, while Wikipedia only counted the deaths going out. The site doesn’t break down the cause of death but says that the “majority” died of illness.
3) This site says that “several” crew members died of scurvy by early 1499, but also says that only 54 made it in the end. That seems a little weird; you’d expect that most of the deaths would have happened before the last six days of the trip (if we’re maximally generous and say that “early 1499″ means “01/01/1499”)
4) This site says Vasco started with 130 people and came back with 59, but doesn’t provide any statistics as to cause of death.
It seems like everyone agrees that the six-month journey (3 months there, 3 back) was very deadly, and that most of the lethality was due to disease, with scurvy playing a big part in it. But it’s unclear what percent of deaths were due to scurvy and what were due to other nutrient deficiency diseases.
Anson starts off with about 1854 people and “returns” with 188, but about 500 survive (the remainder left partway, since the voyage was broken into stages and they often landed and did other things for months at a time)
Deaths (1385 total, mix of vitamin deficiency, starvation, fever, dystentery, exposure). A partial estimated breakdown is below:
95 (typhus, dystentery)
1 (cerebral malaria)
366 (scurvy, hemorhage, niacin deficiency, frostbite, and other assorted diseases)
An unknown amount died on the Pearl and Severn due to dysentery, scurvy, niacin deficiency, and other illnesses
203 (scurvy, shipwreck, starvation, enemy action)
“Most” of 132 marines aboard the Wagner, let’s be generous and say 60%, so 79 deaths. Causes are unclear, but it’s implied that most of them were due to scurvy.
The Wager later got wrecked in a gale because the commanders were sick (scurvy and vitamin A deficiency) and made stupid decisions.
100 people survived the wreck. 50 died to a mix of starvation and enemy action. Another 17 died to scurvy and vitamin A deficiency.
100 (dystentery, vitamin deficiencies)
Notably, only 188 people completed the trip; but ~500 survived. So while the Anson statistic is technically true, it’s pretty misleading right off the bat. Moreover, it seems clear from reading the article that the deaths had a wide range of causes, not just scurvy — the article in particular emphasizes niacin and vitamin A deficiency. Now, I’m sure there was a lot of overlap, but equally, it seems clear that fixing scurvy isn’t going to solve the actual problem of “our sailors keep dying”. I think the 50% statistic, even if maybe technically true, is misleading because it implies that scurvy was the biggest killer when niacin and vitamin A deficiencies seem like they were equally big problems.
Wikipedia says his mission began on 08/29/1498 and ended on 01/07/1499 (so about 3 months).
It looks like this is just one leg of the return journey. In total the outward journey was about 10 months and the return was about 11, and both spent 3+ months without landing.
Sticking my neck out: roll to disbelieve that 50% of sailors on major voyages died in general, let alone specifically of scurvy.
Ways to change the claim that I’d find much more believable:
50% of those who got scurvy died of it
A 50% death rate was considered plausible, and the possibility was planned for, but it wasn’t common
“Major voyage” here is a much smaller category than I expect; think Magellan rather than Columbus.
I tracked the claim back to Wikipedia and from there to this article.
Searching more broadly turned up this, which at least has a few claims we can check easily.
1) Vasco’s mission lost 116⁄170 people. 1) Wikipedia says his mission began on 08/29/1498 and ended on 01/07/1499 (so about 3 months). Half died, many of the rest had scurvy. 2) This site says only 54 of Vasco’s crew “returned with him”; presumably the discrepancy in deaths here is because this site is counting the deaths incurred on both leaving and coming back, while Wikipedia only counted the deaths going out. The site doesn’t break down the cause of death but says that the “majority” died of illness. 3) This site says that “several” crew members died of scurvy by early 1499, but also says that only 54 made it in the end. That seems a little weird; you’d expect that most of the deaths would have happened before the last six days of the trip (if we’re maximally generous and say that “early 1499″ means “01/01/1499”) 4) This site says Vasco started with 130 people and came back with 59, but doesn’t provide any statistics as to cause of death.
It seems like everyone agrees that the six-month journey (3 months there, 3 back) was very deadly, and that most of the lethality was due to disease, with scurvy playing a big part in it. But it’s unclear what percent of deaths were due to scurvy and what were due to other nutrient deficiency diseases.
2) Anson lost 1666/1854 (!) people.
This NIH article is extremely detailed:
Anson starts off with about 1854 people and “returns” with 188, but about 500 survive (the remainder left partway, since the voyage was broken into stages and they often landed and did other things for months at a time)
Deaths (1385 total, mix of vitamin deficiency, starvation, fever, dystentery, exposure). A partial estimated breakdown is below:
95 (typhus, dystentery)
1 (cerebral malaria)
366 (scurvy, hemorhage, niacin deficiency, frostbite, and other assorted diseases)
An unknown amount died on the Pearl and Severn due to dysentery, scurvy, niacin deficiency, and other illnesses
203 (scurvy, shipwreck, starvation, enemy action)
“Most” of 132 marines aboard the Wagner, let’s be generous and say 60%, so 79 deaths. Causes are unclear, but it’s implied that most of them were due to scurvy.
The Wager later got wrecked in a gale because the commanders were sick (scurvy and vitamin A deficiency) and made stupid decisions.
100 people survived the wreck. 50 died to a mix of starvation and enemy action. Another 17 died to scurvy and vitamin A deficiency.
100 (dystentery, vitamin deficiencies)
Notably, only 188 people completed the trip; but ~500 survived. So while the Anson statistic is technically true, it’s pretty misleading right off the bat. Moreover, it seems clear from reading the article that the deaths had a wide range of causes, not just scurvy — the article in particular emphasizes niacin and vitamin A deficiency. Now, I’m sure there was a lot of overlap, but equally, it seems clear that fixing scurvy isn’t going to solve the actual problem of “our sailors keep dying”. I think the 50% statistic, even if maybe technically true, is misleading because it implies that scurvy was the biggest killer when niacin and vitamin A deficiencies seem like they were equally big problems.
Nice!
It looks like this is just one leg of the return journey. In total the outward journey was about 10 months and the return was about 11, and both spent 3+ months without landing.