Based on what I know about the words “professor” and “emeritus” and “cornell”, I assume this is written by an authority in the field of nutrition.
The value of being an authority in a field is that you can accurately convey the consensus within that field. Whenever consensus within a field does not exist, the ancient injunction against “argument from authority” remains true. The “authority” derives not from the authoritative individuals themselves, but the collective wisdom of the field to which they’ve been exposed.
Science is crap. Don’t believe expert predictions about the natural world.
Science isn’t crap—it’s just that when science is weird and inconsistent and wrong it’s obvious and everyone notices because science has better epistemic hygiene practices than non-science methods of discovering things. You’re just overestimating the degree of accuracy and agreement science aught to have.
I might have the specifics of this story wrong, but once upon a time, scientists (correctly) showed that blood cholesterol is correlated with bad things. So people stopped eating more than 1-2 eggs a day. Now we know dietary cholesterol doesn’t directly control blood cholesterol and you can eat lots of eggs and your LDL won’t rise in a meaningful way. That doesn’t make the original findings wrong, it just means the resulting interpretation was wrong. The original scientists weren’t being dumb, it was perfectly reasonable interpretation to make.
The China study found some probably correct things assuming they followed protocol and did statistics well, and now they’re interpreting it to mean “go vegan”. As a consumer of primary research, you should ask yourself if the findings → practical interpretation link is reasonable.
nutrition science is crap
It’s really not significantly different from “we thought there was Aether, and now we don’t”, but in fields like economics and psychology and nutrition people notice more when you mess up, because laymen understand enough to know what it means to make a mistake—Everybody votes, deals with minds, and eats, but most people don’t understand the implications of their not being an aether. .
But, yeah—scientists are people, and some fields tend get more contaminated with personal biases that the researchers might have acquired entirely outside the laboratory. This can inform the types of questions they study, confirmation bias, bias in the interpretation of the data, and so on. Also, whenever an issue of public policy is at stake, I imagine special interests groups get involved.
Why isn’t this good enough to inform your dietary choices?
The evidence certainly does inform my hypothesis, but that’s not the same thing as agreeing with the author’s interpretation. (I don’t say “choices”, because my interest is mostly academic and I’m not particularly diet conscious in my personal life, and I do factor in moral concerns with respect to meat, which makes my actual diet not particularly in line with what I think is nutritionally optimal.)
The important thing is to inform ones views based on the evidence gathered, rather than trusting the researcher to interpret their own evidence.
I accept that chinese diets are likely superior to Western diet. Leafs, shoots, roots, fruits, nuts, and the like are all extremely, extremely important. When meat replaces or otherwise funges against those foods (as you’d expect it to given limited calories per day) meat is bad. The average American lives on meat and grains, skipping the fruits and veggies, and that’s no good. The average American vegetarian will probably be healthier than the average American omnivore for this reason, even controlling for caloric intake. The average American would probably benefit from going vegetarian, not to mention the various moral horrors and environmental damage meat entails. It’s not surprising that we see the same trend in China.
But, well—none of that means that vegan is nutritionally optimal. Hunter gatherers, lacking grains and dairy to provide calories, would have probably “maxed out” the benefits leafs, shoots, roots, fruits, nuts, and other plants despite also eating lots of meat. The Inuit pretty much just eat meat and do fine. (Don’t try it at home—the Inuit can only do this through judicious consumption of organ meats, which are glycogen rich and nutrient dense. They actually often discard the lean muscle meat, probably because they’ve intuitively grasped the macro-nutrient ratio problem it would pose.)
When you look at the evidence provided from the China study—not the interpretations, just the evidence - there’s very little room for suggesting that hunter-gatherer diets are suboptimal.
Assuming you don’t plan to become an expert in the field of nutrition yourself, what’s a better way to inform your dietary choices?
There’s no way out. I can say “Eat a balanced diet, with natural real foods” or whatever but the true meaning of “balanced” and “natural” is a lot more controversial than it seems at first. If you don’t do your research you are down to guesswork, and after you do your research you are still mostly down to guesswork due to how little we really know.
FWIW, having a totally optimal diet is probably not extremely important in the grand scheme of things. For all practical purposes you’ll be just fine so long as (1) your calories are okay, (2) your macronutrient ratios are not horribly awful, (3) you have no obvious symptoms of micronutrient deficiency, and (4) you exercise. Everyone agrees on those four and that you should eat fruits and veggies. Beyond that, it’s all controversial and I doubt the additional worrying will really buy you that many extra years of quality health when one factors in the likelihood of choosing the correct arguments among the controversy. (Outside view. Inside view, I totally think I’m right in choosing the “take cues from hunter gatherers” thing.)
Based on what I know about the words “professor” and “emeritus” and “cornell”, I assume this is written by an authority in the field of nutrition.
The value of being an authority in a field is that you can accurately convey the consensus within that field. Whenever consensus within a field does not exist, the ancient injunction against “argument from authority” remains true. The “authority” derives not from the authoritative individuals themselves, but the collective wisdom of the field to which they’ve been exposed.
Who says there is no consensus? Given that he’s a nutrition science authority, and that other nutrition science authorities aren’t refuting him, that’s some small evidence that he’s representing a consensus (there are other possible explanations as well, that I touched on in my OP).
Notice Campbell cites a chain of three variables: Cancer associates with cholesterol, cholesterol associates with animal protein, and therefore we infer that animal protein associates with cancer. Or from another angle: Cancer associates with cholesterol, cholesterol negatively associates with plant protein, and therefore we infer plant protein protects against cancer.
But when we actually track down the direct correlation between animal protein and cancer, there is no statistically significant positive trend. None. Looking directly at animal protein intake, we have the following correlations with cancers:
I’ve seen her critique, but with her being a blogger and me being neither a statistician, epidemiologist, nor a nutritionist, and after seeing the resulting fight about methodology in the comments by people who claim to be those things, and knowing that Campbell stands by his claims even after reading her critique and has written his response, and with me having a rather low base rate confidence in any given study being correct anyway, it didn’t influence my opinion that much in any direction.
I’m pretty much out of my depth insofar as methodology is concerned in this case so, I’m not really in a position to evaluate anything on those grounds, yet. It at least feels more productive to just skim tons of abstracts and get a big picture idea than to analyze whether one particular study is correct.
Also, there’s a big difference between the claims of The China Study book which cites a range of findings (some of which I believe fall into the “made sense at the time but are now outdated” category), and the findings of the China-Oxford-Cornell study in particular, and as I read her critique it seems she’s getting those two confounded.
PS—The “meat, especially red meat, is carcinogenic” claim is one of those for which Cambell provided fairly robust support from other studies, not relying on the China-Oxford-Cornell data alone. I think subsequent research found that preserved meat (deli, smoked, etc) and maybe various common methods of grilling explain the carcinogenic factor, but don’t quote or trust me. (Not that I have strong priors against meat being carcinogenic, the “ancestral environment” arguments might not hold for extremely late-stage diseases like cancer)
me having a rather low base rate confidence in any given study being correct anyway, it didn’t influence my opinion that much in any direction.
If your prior is that the study likely doesn’t provide much value then this might not change your opinion. On the other hand reaffirm your priors should mean not putting much weight in Campbell case.
On the other hand reaffirm your priors should mean not putting much weight in Campbell case.
Not sure I understand what is meant by this.
Was trying to say: The data brings value. I don’t trust conclusions drawn from data. I also don’t trust Minger’s belief that the data analysis was obviously flawed because I see many people arguing over that. Rather than investigating further about Minger vs. Cambell on an argument that has experts disagreeing, it’s more worthwhile as a reader to just provisionally assume the data analysis is passable and read more on the topic elsewhere, because the risk of being mislead by flawed data analysis or other methodological issues is ever present, and in a field like this one is better off reading widely and look for broad trends and conceptual replications than one is by reading extremely closely. (And hoping any wrong beliefs brought about by bad data analysis fall away because the other experiments don’t support them.)
That’s what I mean by “low base rate”. If I’m just reading to get a big picture of reality in a field, rather than dive into the difficult rabbit hole of “are the methods ok”, I just operate under the assumption that there’s always an x% risk of any given study being flat-out wrong about everything and keep reading more without worrying about it.
(Which is why “Minger disagrees with those methods” falls into the “well, methods are frequently complicated and controversial and you’ve already factored that in so don’t worry” box. If other experts unanimously chimed in agreement with Minger, or if what she wrote about the flaws seemed obviously true to me, it would be a different matter).
I’ve come across this quite often. This is written by an amateur whose authority stems from “I typically spend about five hours a day reading and writing about nutrition—voluntarily”.
As a layperson myself I’d be a lot more moved if other nutrition scientists agreed with her. As it stands for me her input is basically +1 “non-nutrition scientists disagree’ with Campbell”.
The value of being an authority in a field is that you can accurately convey the consensus within that field. Whenever consensus within a field does not exist, the ancient injunction against “argument from authority” remains true. The “authority” derives not from the authoritative individuals themselves, but the collective wisdom of the field to which they’ve been exposed.
Science isn’t crap—it’s just that when science is weird and inconsistent and wrong it’s obvious and everyone notices because science has better epistemic hygiene practices than non-science methods of discovering things. You’re just overestimating the degree of accuracy and agreement science aught to have.
I might have the specifics of this story wrong, but once upon a time, scientists (correctly) showed that blood cholesterol is correlated with bad things. So people stopped eating more than 1-2 eggs a day. Now we know dietary cholesterol doesn’t directly control blood cholesterol and you can eat lots of eggs and your LDL won’t rise in a meaningful way. That doesn’t make the original findings wrong, it just means the resulting interpretation was wrong. The original scientists weren’t being dumb, it was perfectly reasonable interpretation to make.
The China study found some probably correct things assuming they followed protocol and did statistics well, and now they’re interpreting it to mean “go vegan”. As a consumer of primary research, you should ask yourself if the findings → practical interpretation link is reasonable.
It’s really not significantly different from “we thought there was Aether, and now we don’t”, but in fields like economics and psychology and nutrition people notice more when you mess up, because laymen understand enough to know what it means to make a mistake—Everybody votes, deals with minds, and eats, but most people don’t understand the implications of their not being an aether. .
But, yeah—scientists are people, and some fields tend get more contaminated with personal biases that the researchers might have acquired entirely outside the laboratory. This can inform the types of questions they study, confirmation bias, bias in the interpretation of the data, and so on. Also, whenever an issue of public policy is at stake, I imagine special interests groups get involved.
The evidence certainly does inform my hypothesis, but that’s not the same thing as agreeing with the author’s interpretation. (I don’t say “choices”, because my interest is mostly academic and I’m not particularly diet conscious in my personal life, and I do factor in moral concerns with respect to meat, which makes my actual diet not particularly in line with what I think is nutritionally optimal.)
The important thing is to inform ones views based on the evidence gathered, rather than trusting the researcher to interpret their own evidence.
I accept that chinese diets are likely superior to Western diet. Leafs, shoots, roots, fruits, nuts, and the like are all extremely, extremely important. When meat replaces or otherwise funges against those foods (as you’d expect it to given limited calories per day) meat is bad. The average American lives on meat and grains, skipping the fruits and veggies, and that’s no good. The average American vegetarian will probably be healthier than the average American omnivore for this reason, even controlling for caloric intake. The average American would probably benefit from going vegetarian, not to mention the various moral horrors and environmental damage meat entails. It’s not surprising that we see the same trend in China.
But, well—none of that means that vegan is nutritionally optimal. Hunter gatherers, lacking grains and dairy to provide calories, would have probably “maxed out” the benefits leafs, shoots, roots, fruits, nuts, and other plants despite also eating lots of meat. The Inuit pretty much just eat meat and do fine. (Don’t try it at home—the Inuit can only do this through judicious consumption of organ meats, which are glycogen rich and nutrient dense. They actually often discard the lean muscle meat, probably because they’ve intuitively grasped the macro-nutrient ratio problem it would pose.)
When you look at the evidence provided from the China study—not the interpretations, just the evidence - there’s very little room for suggesting that hunter-gatherer diets are suboptimal.
There’s no way out. I can say “Eat a balanced diet, with natural real foods” or whatever but the true meaning of “balanced” and “natural” is a lot more controversial than it seems at first. If you don’t do your research you are down to guesswork, and after you do your research you are still mostly down to guesswork due to how little we really know.
FWIW, having a totally optimal diet is probably not extremely important in the grand scheme of things. For all practical purposes you’ll be just fine so long as (1) your calories are okay, (2) your macronutrient ratios are not horribly awful, (3) you have no obvious symptoms of micronutrient deficiency, and (4) you exercise. Everyone agrees on those four and that you should eat fruits and veggies. Beyond that, it’s all controversial and I doubt the additional worrying will really buy you that many extra years of quality health when one factors in the likelihood of choosing the correct arguments among the controversy. (Outside view. Inside view, I totally think I’m right in choosing the “take cues from hunter gatherers” thing.)
Who says there is no consensus? Given that he’s a nutrition science authority, and that other nutrition science authorities aren’t refuting him, that’s some small evidence that he’s representing a consensus (there are other possible explanations as well, that I touched on in my OP).
I don’t think they did statistics well:
I’ve seen her critique, but with her being a blogger and me being neither a statistician, epidemiologist, nor a nutritionist, and after seeing the resulting fight about methodology in the comments by people who claim to be those things, and knowing that Campbell stands by his claims even after reading her critique and has written his response, and with me having a rather low base rate confidence in any given study being correct anyway, it didn’t influence my opinion that much in any direction.
I’m pretty much out of my depth insofar as methodology is concerned in this case so, I’m not really in a position to evaluate anything on those grounds, yet. It at least feels more productive to just skim tons of abstracts and get a big picture idea than to analyze whether one particular study is correct.
Also, there’s a big difference between the claims of The China Study book which cites a range of findings (some of which I believe fall into the “made sense at the time but are now outdated” category), and the findings of the China-Oxford-Cornell study in particular, and as I read her critique it seems she’s getting those two confounded.
PS—The “meat, especially red meat, is carcinogenic” claim is one of those for which Cambell provided fairly robust support from other studies, not relying on the China-Oxford-Cornell data alone. I think subsequent research found that preserved meat (deli, smoked, etc) and maybe various common methods of grilling explain the carcinogenic factor, but don’t quote or trust me. (Not that I have strong priors against meat being carcinogenic, the “ancestral environment” arguments might not hold for extremely late-stage diseases like cancer)
If your prior is that the study likely doesn’t provide much value then this might not change your opinion. On the other hand reaffirm your priors should mean not putting much weight in Campbell case.
Not sure I understand what is meant by this.
Was trying to say: The data brings value. I don’t trust conclusions drawn from data. I also don’t trust Minger’s belief that the data analysis was obviously flawed because I see many people arguing over that. Rather than investigating further about Minger vs. Cambell on an argument that has experts disagreeing, it’s more worthwhile as a reader to just provisionally assume the data analysis is passable and read more on the topic elsewhere, because the risk of being mislead by flawed data analysis or other methodological issues is ever present, and in a field like this one is better off reading widely and look for broad trends and conceptual replications than one is by reading extremely closely. (And hoping any wrong beliefs brought about by bad data analysis fall away because the other experiments don’t support them.)
That’s what I mean by “low base rate”. If I’m just reading to get a big picture of reality in a field, rather than dive into the difficult rabbit hole of “are the methods ok”, I just operate under the assumption that there’s always an x% risk of any given study being flat-out wrong about everything and keep reading more without worrying about it.
(Which is why “Minger disagrees with those methods” falls into the “well, methods are frequently complicated and controversial and you’ve already factored that in so don’t worry” box. If other experts unanimously chimed in agreement with Minger, or if what she wrote about the flaws seemed obviously true to me, it would be a different matter).
I’ve come across this quite often. This is written by an amateur whose authority stems from “I typically spend about five hours a day reading and writing about nutrition—voluntarily”.
As a layperson myself I’d be a lot more moved if other nutrition scientists agreed with her. As it stands for me her input is basically +1 “non-nutrition scientists disagree’ with Campbell”.