At first glance, I thought you were claiming that copper tubing and air exposure does not destroy vitamin C, but now I think I read you backwards. I think you are claiming that they do destroy vitamin C, and that copper and O2 destruction of vitamin C was the only reason that “lime juice” was failing to prevent scurvy (and that the differences between lemons vs. limes had nothing to do with it).
Yeah, your current interpretation is correct.
This article finds that Musk limes have less than half the vitamin C of lemons, just to gesture in that direction.
It’s not that different from the raw limes in USDA’s data. In the titration method, that article found that musk limes had 42.3% as much vitamin C as lemons, and in the HPLC method, 53.5%. The average of those is 47.9%. My data on non-musk limes suggest they have 54.7% as much vitamin C as lemons.
The quote you gave for lemon vitamin C is the minimum value listed in the source. The maximum is 43.3mg/100g
I’m confused. The number I listed for lemon vitamin C was 53mg/100g.
I think we have adequate evidence to say that bear meat could have prevented scurvy in Arctic explorers if lightly cooked.
To be clear, I wasn’t arguing against that. I was just pointing out that it’s misleading to claim that polar bear meat is more like lemons than limes are. All 3 of those things seem able to prevent scurvy when they’re fresh and consumed in reasonable quantities; even 1⁄4 of the vitamin C concentration of fresh lemon juice is 23.22mg per cup. It’s possible that a citrus species has an abnormally low vitamin C concentration, and it’s possible that 10mg of vitamin C from lime juice is not the same as 10mg of vitamin C from fresh meat. But SMTM was asserting as a known fact that Sicilian lemons are more like polar bear meat than they are like West Indian limes in their ability to treat scurvy, which in expectation causes people who read the post to be worse at predicting the data we found than they would be if they had never read it, and that is what I was objecting to.
Apologies, I missed several of these points in your OP at first, and edited my post to correct it. Sorry you saw it before it was fixed!!!
I was just pointing out that it’s misleading to claim that polar bear meat is more like lemons than limes are.
I agree with your characterization of SMTM’s argument. It’s hard to parse, given the reference to his own made-up dialog that’s partly to make (supposedly) factual claims and partly to illustrate the challenges of analyzing complex scientific data. However, I read this as SMTM in their authorial voice defending the claim that key limes don’t contain vitamin C and polar bear meat does. We both agree this claim is false. Here’s the relevant quote:
Frolich:Maybe some citrus fruits contain the antiscorbutic [scurvy-curing] property and others don’t. Maybe the British Royal Navy used one kind of lime back when Lind did his research but gave a different kind of lime to Nares and the others on their Arctic expeditions. Or maybe they did something to the lime juice that removed the antiscorbutic property. Maybe they boiled it, or ran it through copper piping or something, and that ruined it.
Maybe there are different kinds of citrus. Maybe some animals need this mystery ingredient and others don’t. Maybe polar bear meat is, medically speaking, more like citrus fruit from Sicily than like citrus fruit from the West Indies. Really???
This looks a lot like special pleading, but in this case, the apparent double standard is correct. All of these weird exceptions he suggests were actually weird exceptions. And while our hypothetical version of Frolich wouldn’t have any way of knowing, these were the right distinctions to make.
I think that SMTM got this fact wrong. However, I think that the essential point of the SMTM article holds, and by extension the analogy I am drawing between vitamin C and sleep.
Thank you for your patience with my original slip-ups in noticing the full content of your preceding comment.
“Different kinds of citrus fruits are more like one another than they are like polar bear meat” sounds very reasonable, but in this case it was wrong. Sicilian lemons really ARE more like polar bear meat than they are like West Indian limes, at least for the purposes of treating scurvy.
Followup: SMTM points out that differences in fertilization and propagation (clonally or by seed) mean that we don’t know whether or not historical key limes had enough vitamin C to cure scurvy. I notice in myself a certain tendency to say oh puh-leeze in response to this, but at the same time, I think the broader point of the original SMTM piece is that it’s precisely this reaction that we ought to be suspicious of. After all, we don’t necessarily know that the arctic explorers who found that lime juice didn’t cure their scurvy were drinking it out of copper tubes, or that the vitamin C in the lime juice they were drinking was oxidized.
SMTM points out that differences in fertilization and propagation (clonally or by seed) mean that we don’t know whether or not historical key limes had enough vitamin C to cure scurvy.
Hm, that would still make the post misleading — “Sicilian lemons really ARE more like polar bear meat than they are like West Indian limes, at least for the purposes of treating scurvy” is a very different claim from “we don’t know whether or not historical key limes had enough vitamin C to cure scurvy.”
Yeah, your current interpretation is correct.
It’s not that different from the raw limes in USDA’s data. In the titration method, that article found that musk limes had 42.3% as much vitamin C as lemons, and in the HPLC method, 53.5%. The average of those is 47.9%. My data on non-musk limes suggest they have 54.7% as much vitamin C as lemons.
I’m confused. The number I listed for lemon vitamin C was 53mg/100g.
To be clear, I wasn’t arguing against that. I was just pointing out that it’s misleading to claim that polar bear meat is more like lemons than limes are. All 3 of those things seem able to prevent scurvy when they’re fresh and consumed in reasonable quantities; even 1⁄4 of the vitamin C concentration of fresh lemon juice is 23.22mg per cup. It’s possible that a citrus species has an abnormally low vitamin C concentration, and it’s possible that 10mg of vitamin C from lime juice is not the same as 10mg of vitamin C from fresh meat. But SMTM was asserting as a known fact that Sicilian lemons are more like polar bear meat than they are like West Indian limes in their ability to treat scurvy, which in expectation causes people who read the post to be worse at predicting the data we found than they would be if they had never read it, and that is what I was objecting to.
Apologies, I missed several of these points in your OP at first, and edited my post to correct it. Sorry you saw it before it was fixed!!!
I agree with your characterization of SMTM’s argument. It’s hard to parse, given the reference to his own made-up dialog that’s partly to make (supposedly) factual claims and partly to illustrate the challenges of analyzing complex scientific data. However, I read this as SMTM in their authorial voice defending the claim that key limes don’t contain vitamin C and polar bear meat does. We both agree this claim is false. Here’s the relevant quote:
I think that SMTM got this fact wrong. However, I think that the essential point of the SMTM article holds, and by extension the analogy I am drawing between vitamin C and sleep.
Thank you for your patience with my original slip-ups in noticing the full content of your preceding comment.
There was also another relevant passage:
Followup: SMTM points out that differences in fertilization and propagation (clonally or by seed) mean that we don’t know whether or not historical key limes had enough vitamin C to cure scurvy. I notice in myself a certain tendency to say oh puh-leeze in response to this, but at the same time, I think the broader point of the original SMTM piece is that it’s precisely this reaction that we ought to be suspicious of. After all, we don’t necessarily know that the arctic explorers who found that lime juice didn’t cure their scurvy were drinking it out of copper tubes, or that the vitamin C in the lime juice they were drinking was oxidized.
Reality is surprisingly complex.
Hm, that would still make the post misleading — “Sicilian lemons really ARE more like polar bear meat than they are like West Indian limes, at least for the purposes of treating scurvy” is a very different claim from “we don’t know whether or not historical key limes had enough vitamin C to cure scurvy.”
Thanks for contacting them, though!
Agreed!
I will see if I can get in touch with SMTM and IW, I’d be curious what they have to say about this.