AHS-2 [the Adventist Health Study 2] does have some comparisons between omnivores to vegans. From the abstract: “the adjusted hazard ratio (HR) for all-cause mortality in all vegetarians combined vs non-vegetarians was 0.88 (95% CI, 0.80–0.97). The adjusted HR for all-cause mortality in vegans was 0.85 (95% CI, 0.73–1.01)”. So depending on how strict you are being with statistical significance there’s somewhere between a small signal and no signal that veganism is better with respect to all-cause mortality than omnivorism.
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I think I would be confident enough in the AHS data to say that it shows that veg*nism does not entail a tradeoff on the ‘years of life lived’ axis. The most conservative reading of the data possible would be that a veg*n diet has no effect on years of life lived, and I think it is probably more reasonable to read the AHS study as likely underestimating the benefits a veg*n diet would give the average person. Obviously ‘years of life lived’ is not the same thing as ‘health’ so I’m not saying this is a knock-down argument against your main point—just wanted to contextualise how we were using the data in the linked piece.
AHS-2 is not a longitudinal RCT where diet is randomly assigned, but neither is the Faunalytics ex-veg*an survey. I think AHS-2 is instructive because it looks at an objective clinical outcome (all-cause mortality).
I also think that, in addition to the Adventist observational study, there are vegan diet RCTs that have useful context for this discussion. This systematic review of RCTs concludes that
In comparison with control diets, vegan diets reduced body weight (-4.1 kg, 95% confidence interval (CI) −5.9 to −2.4, p < 0.001), body mass index (BMI) (-1.38 kg/m2 , 95% CI −1.96 to −0.80, p < 0.001), glycated hemoglobin (HbA1c ) (-0.18% points, 95% CI −0.29 to −0.07, p = 0.002), total cholesterol (-0.30 mmol/L, 95% CI −0.52 to −0.08, p = 0.007), and low-density lipoprotein cholesterol (-0.24 mmol/L, 95% CI −0.40 to −0.07, p = 0.005).
Putting those things together, I would say it’s not at all obvious that a well-planned vegan diet has health tradeoffs ex-ante. There is a substantial probability that it would make you healthier, all things considered.
Of course, taking B12 is important, and like wilkox, I would not disagree with this post if it just said “PSA: if you are vegan, you might not know you are at increased risk of certain nutrient deficiencies; read (this link) to find out more and see your doctor if you have (list of symptoms) or want to get tested.” However, this post took a different approach, which makes it look like you might think there’s a deeper ex-ante problem with being vegan, and I think it’s very unclear that there is.
But that is not what this post said, which makes it look like you might think there’s a deeper ex-ante problem with being vegan, and I think it’s very unclear that there is.
I read the post not as claiming that veganism has deeper ex ante problems, but that responsible vegan advocacy should include the PSA you mention (or people should convince Elizabeth that the PSA is not actually necessary).
It feels weird to me that you describe this as “missing context”, when the whole point of the post is “I might be missing evidence, please show it to me”. The 7DA data is easily the best answer I’ve gotten so far and it makes me very glad I asked.
PSA: if you are vegan, you might not know you are at increased risk of certain nutrient deficiencies; read (this link) to find out more and see your doctor if you have (list of symptoms) or want to get tested
I did. I also provided tests and supplement suggestions (none of which, AFAIK, led to anyone resuming animal consumption), and tried to get the ball rolling on vegans helping vegans. I kept getting pushback, public and private, that felt extremely epistemically uncooperative. People did not necessarily outright say “everyone can switch to veganism naively and suffer no trade-offs”, but the things they did say only made sense if that were true. This post is an attempt to get clarity on a fairly narrow question. I get why it feels loaded, but anything less blunt or less focused got rebuffed in obfuscated ways.
I love the Adventist study and hope to get to a deep dive soon. However since it focuses on vegetarians, not vegans, and I think those are very different, I don’t expect it to update me much about veganism. I also don’t think it will be informative about uninformed diets or transitions, since these are people growing up a culture that holds their dietary choices rather than switching.
The cardiac RCT looks very interesting, I will need some time to dig into that. Before I do, are there any flaws you want to declare ahead of time? Is this a paper you personally put high confidence in?
I see it did cite a specific vegan hazard ratio, however that ratio is tied with pescetarianism in men, and well above both pescetarianism and 1/week meat consumption in women. If you take this at face value it suggests small-but-present meat consumption, in addition to millk and eggs, are good for women, and fish at least is good for men.
[Note that the pescevegetarian and semivegetarian categories include unlimited milk and egg consumption]
Given the wide and greatly overlapping confidence intervals for all diets among women, it might be more fitting to interpret these tables as suggesting that “animal product consumption pattern doesn’t seem associated with mortality among women in this sample” than that “small-but-present meat consumption, in addition to millk and eggs, are good for women.” Based on the data presented, a variety of diets could potentially be optimal, and there isn’t a big difference between them. I think this fits my initial conclusion that veganism isn’t obviously bad for your health ex-ante if you supplement e.g. B12.
@Natália Coelho Mendonça I would really appreciate a reply or at least acknowledgement of my comment here. I took your initial comment to be a very strong endorsement of the paper in ways I think make a reply a fair request.
[note: this comment was edited after people’s replies.]
Someone on the EA Forum brought up an interesting study
AHS-2 is not a longitudinal RCT where diet is randomly assigned, but neither is the Faunalytics ex-veg*an survey. I think AHS-2 is instructive because it looks at an objective clinical outcome (all-cause mortality).
I also think that, in addition to the Adventist observational study, there are vegan diet RCTs that have useful context for this discussion. This systematic review of RCTs concludes that
Putting those things together, I would say it’s not at all obvious that a well-planned vegan diet has health tradeoffs ex-ante. There is a substantial probability that it would make you healthier, all things considered.
Of course, taking B12 is important, and like wilkox, I would not disagree with this post if it just said “PSA: if you are vegan, you might not know you are at increased risk of certain nutrient deficiencies; read (this link) to find out more and see your doctor if you have (list of symptoms) or want to get tested.” However, this post took a different approach, which makes it look like you might think there’s a deeper ex-ante problem with being vegan, and I think it’s very unclear that there is.
I read the post not as claiming that veganism has deeper ex ante problems, but that responsible vegan advocacy should include the PSA you mention (or people should convince Elizabeth that the PSA is not actually necessary).
It feels weird to me that you describe this as “missing context”, when the whole point of the post is “I might be missing evidence, please show it to me”. The 7DA data is easily the best answer I’ve gotten so far and it makes me very glad I asked.
I did. I also provided tests and supplement suggestions (none of which, AFAIK, led to anyone resuming animal consumption), and tried to get the ball rolling on vegans helping vegans. I kept getting pushback, public and private, that felt extremely epistemically uncooperative. People did not necessarily outright say “everyone can switch to veganism naively and suffer no trade-offs”, but the things they did say only made sense if that were true. This post is an attempt to get clarity on a fairly narrow question. I get why it feels loaded, but anything less blunt or less focused got rebuffed in obfuscated ways.
I love the Adventist study and hope to get to a deep dive soon. However since it focuses on vegetarians, not vegans, and I think those are very different, I don’t expect it to update me much about veganism. I also don’t think it will be informative about uninformed diets or transitions, since these are people growing up a culture that holds their dietary choices rather than switching.
The cardiac RCT looks very interesting, I will need some time to dig into that. Before I do, are there any flaws you want to declare ahead of time? Is this a paper you personally put high confidence in?
That’s not true. The Adventist study I cited explicitly calculated the mortality hazard ratio for vegans, separately from non-vegan vegetarians.
(I’ll reply to the questions in your last paragraph soon).
I see it did cite a specific vegan hazard ratio, however that ratio is tied with pescetarianism in men, and well above both pescetarianism and 1/week meat consumption in women. If you take this at face value it suggests small-but-present meat consumption, in addition to millk and eggs, are good for women, and fish at least is good for men.
[Note that the pescevegetarian and semivegetarian categories include unlimited milk and egg consumption]
Given the wide and greatly overlapping confidence intervals for all diets among women, it might be more fitting to interpret these tables as suggesting that “animal product consumption pattern doesn’t seem associated with mortality among women in this sample” than that “small-but-present meat consumption, in addition to millk and eggs, are good for women.” Based on the data presented, a variety of diets could potentially be optimal, and there isn’t a big difference between them. I think this fits my initial conclusion that veganism isn’t obviously bad for your health ex-ante if you supplement e.g. B12.
[Details here.]
@Natália Coelho Mendonça I would really appreciate a reply or at least acknowledgement of my comment here. I took your initial comment to be a very strong endorsement of the paper in ways I think make a reply a fair request.
Oh cool, I misread a comment from the author.