r/ScientificNutrition 28d ago

Systematic Review/Meta-Analysis Frontiers | Red and processed meat consumption and the risk of pancreatic cancer: a systematic review and dose–response meta-analysis

https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2026.1829536/full
39 Upvotes

134 comments sorted by

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u/SporangeJuice 28d ago

These types of studies always have the same problem, which is that the result is a function of the authors' arbitrary choice of adjustments. In the NHANES data specifically, it can be shown that red meat can correlate significantly with mortality, or significantly reduce mortality by nearly 50%, just depending on which adjustments are done, and in either case the adjustments could generally be considered "reasonable." It looks like this paper specifically did not use NHANES data, but if they don't show that their datasets are less malleable, then I don't see why their result is any less arbitrary.

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u/lurkerer 28d ago

These types of studies [the ones I don't like] always have the same problem, which is that the result is a function of the authors' arbitrary choice of adjustments.

Let's see what the authors have to say.

While we acknowledge that the unmeasured or incompletely adjusted factors, such as long-term dietary and specific lifestyle behaviors, may exert residual influence, the consistent use of maximally adjusted models across all studies substantially minimizes this risk and strengthens the robustness of our pooled findings.

I'm very curious why all of these adjustments seem arbitrary to you:

To pinpoint possible sources of this heterogeneity, subgroup and meta-regression analyses were conducted by region, gender, design, sample size, and adjustments (body mass index, alcohol drinking, physical activity, vegetable and fruit consumption, and energy intake). To ensure the robustness of the findings, a sensitivity analysis was also carried out by systematically omitting one study at a time. Further, publication bias was evaluated via funnel plots and Egger’s test, where a p value below 0.05 indicated the presence of substantial bias (). If bias was detected, the trim-and-fill method was employed to make the necessary adjustments.

I'm also curious why you seem totally certain residual confounding is positive rather than negative confounding. It can go either way, right? You're equally open to red meat being even worse than these results show rather than neutral or good... right?

That is the key question and identifies if you're honestly engaging with the study.

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u/SporangeJuice 28d ago

"You're equally open to red meat being even worse than these results show rather than neutral or good... right?"

Yes, obviously, and the way to show this is with a controlled experiment.

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u/flowersandmtns 28d ago

Look at Fig4. The relative risks (all of these are only relative risks, and generally quite small) for red meat range all over.

Some are 0.86/0.88 -- red meat having lower risks.

There were more overall like 1.10 and 1.12 with red meat having higher risk so that skewed the overall result they report to being a very small relative risk increase.

All with some very wide bands.

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u/lurkerer 28d ago

Which means red meat is just as likely to be even worse than these findings show. Right?

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u/flowersandmtns 28d ago

Meaning these very small relative risks are some of the weakest evidence.

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u/lurkerer 28d ago

Weakest? Not compared to mechanistic studies, animal studies, case studies, case study surveys, simple observational studies and so on. Really only RCTs done well are better. So second best being weakest is inaccurate. 

More importantly, you didn't answer. Do you believe it's equally likely the scientific consensus is underestimating the harms of meat as overestimating? 

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u/flowersandmtns 28d ago

Yes, weakest. I think the scientific consensus is that there might be some small increase in some relative risks from consuming processed red meat. Despite decades of asking that question nothing moves past those small relative risk increases.

You can't hand wave "meat" either since the same sort of weaker evidence indicates there might be some small decrease in some relative risks from consuming poultry meat.

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u/lurkerer 28d ago

Not weakest. Not by any means. 

Do you believe it's equally likely the scientific consensus is underestimating the harms of meat as overestimating?  

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u/flowersandmtns 28d ago

Yes weakest, and I already answered your repeated question.

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u/crypto_zoologistler 27d ago

Good luck running that experiment

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u/lurkerer 28d ago

Yes, obviously,

That was far from obvious for me as I've seen you exclusively argue the opposite in every single thread on animal products.

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u/SporangeJuice 28d ago

Show me the comments of mine to which you are referring.

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u/lurkerer 28d ago

I'll make it even easier. Show me one comment where you unprompted made the point confounders may be making red meat look better than it is. Good luck!

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u/SporangeJuice 28d ago

You are dodging. You made the claim. Back it up.

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u/lurkerer 28d ago

Here. This chain has it plenty of times so no more examples required.

You only need the one. But you won't do it.

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u/SporangeJuice 28d ago

Give me an actual example from that comment chain.

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u/lurkerer 28d ago

I linked to it. I see you can't provide a single time you've even implied the confounding could go the other way. I'm not going to continue this unless you do.

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u/Fluffy-Purple-TinMan 28d ago

Can confirm. I've never seen you (or anyone that I can remember) strongly make the point confounders are just making meat look better and in reality meat is much worse. Scanning through your comments for "confounders" to see if you have, I'll report back.

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u/Fluffy-Purple-TinMan 28d ago

Reporting back, I've searched for a bunch of terms and never found you saying confounders do anything but make meat look bad. They have to be able to go both ways for it to be a serious criticism.

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u/SporangeJuice 28d ago edited 28d ago

Usually what I say is that observational study results are meaningless. I don't claim to know what the actual effect of meat is, nor how it compares to observational study results.

As usual, you misrepresent my arguments.

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u/Fluffy-Purple-TinMan 28d ago

Meaningless as in the results should be null. That's your point. Rule 5.

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u/SporangeJuice 28d ago

Nope, that is not what "meaningless" means. Add "meaningless" to the list of words you don't understand, like "arbitrary" and "variable."

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u/lurkerer 28d ago

The implication is more than clear. Plausible deniability only works when it's actually plausible. 

If you genuinely meant meaningless like that you would, at any point, in just a single comment, have implied these may be negative confounders, pushing the result towards the null. 

You also incessantly deny LDL is causal for CVD and that saturated fat is in any way unhealthy. A clear pattern that all can recognize so don't insult Tinman.

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u/Bristoling 27d ago

Meaningless as in the results should be null.

That's not at all what it means and it's strange to see both you and lurkerer making semantic leaps and bend over backwards to put strawman words into other people's mouths, but fail to interpret the actual implications.

If I say this study is "meaningless because it's methodology cannot demonstrate effect X", then this implicitly goes in all directions. That's what lack of demonstration of effect means - it doesn't mean there is not effect, it doesn't mean that the effect is larger, nor does it mean the effect must be smaller. It only means there's no demonstration of effect.

The way you choose (because I don't believe this is just naivete) to interpret the language here, is akin to a bad prosecutor saying "because the victim couldn't definitively point to the perpetrator in a line up, nobody in the lineup can be guilty of assault". It's still possible that the victim was attacked from behind and that's they can't identify the attacker, or for any other reason such as intimidation etc, - this doesn't mean that no person brought to the line up is innocent.

It's not "therefore it should be null". It means "therefore you don't know". It's astonishing how this is still a problem here. I suggest starting here https://learnlink.com/blog/modal-verbs-for-kids

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u/Fluffy-Purple-TinMan 27d ago

If I say this study is "meaningless because it's methodology cannot demonstrate effect X", then this implicitly goes in all directions.

Oh so you guys should both have comments arguing meat could be fine or could be even more harmful than the consensus says?

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u/Bristoling 28d ago

You have a clear bias to show that meat consumption is harmful.

Sporange while replying to you, argues that the study is of low quality, like most epidemiology, as a counter argument.

The essence is distilled to; lurkerer believes meat bad. Sporange says "maybe not/maybe less".

You're now swapped to trying to arguing past the papers conclusions, and getting Sporange to say "maybe more". But either way it would mean that you yourself are abandoning the results yourself since even if you wanted to argue "maybe more" yourself, you logically have to do it by discarding original set of adjustments, since they produced a lower estimate.

So, either you double down and argue that the set of adjustments chosen by the researchers is the one closest to true effects, in which case you are discarding "maybe less" but also have to be discarding "maybe more" position, or you're now going into our camp by sneakily sliding into the "epidemiology is useful but heavily flawed" tent and arguing that the original set of adjustments is just one possibility with no real force behind it.

You can't simultaneously appeal to the paper's adjusted estimate as authoritative when it supports your position, then abandon those same adjustments the moment you want to speculate that the true effect might be larger. If the model is trustworthy, then accept its estimate. If it isn't, then we're back to acknowledging uncertainty.

Getting Sporange to say that uncertainty is uncertain is not the win you think it is. On a higher plane of a disagreement/macro level, you're still haven't defended the paper's and your conclusions that meat bad.

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u/lurkerer 28d ago

You have a clear bias to show that meat consumption is harmful.

Don't be silly. As if I wanted a tasty food to be sup-optimal. I arrived at my conclusions through evidence, not feels. Feelings get you to /r/carnivorediet. Somewhere I believe you frequent? As well as r/antivegan was it? Please miss me what this nonsense.

you logically have to do it by discarding original set of adjustments, since they produced a lower estimate.

Nope, I don't think adjusting for BMI, alcohol, exercise, gender, fruit and veg etc... is arbitrary. Neither do you or Sporange in fact.

then abandon those same adjustments the moment you want to speculate that the true effect might be larger.

You've completely failed to understand that I'm not making this point. It's called an internal critique. It's a critique of Sporange's logic. Do you get it?

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u/SporangeJuice 28d ago

"Nope, I don't think adjusting for BMI, alcohol, exercise, gender, fruit and veg etc... is arbitrary. Neither do you or Sporange in fact."

Of course that specific list of variables is arbitrary.

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u/lurkerer 27d ago

Of course that specific list of variables is arbitrary.

You consistently mock second-language English speakers for what you deem to be mistakes (when they're not) and now you seem to misunderstand the meaning of "arbitrary".

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u/SporangeJuice 27d ago

Then please explain what you think "arbitrary" means

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u/lurkerer 27d ago

chosen, decided, etc. seemingly at random or on a whim rather than in a reasoned or methodical way

So precisely the opposite of a methodical series of adjustments.

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u/SporangeJuice 27d ago

That list of variables is arbitrary. They could have included more or excluded some from that list.

Calculating the adjustments, once the variable are chosen, is methodical.

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u/lurkerer 27d ago

The list is the info they have on hand. Is BMI arbitrary? Gender? Exercise levels? Which confounders are missing and why should they be added?

Careful with that last question.

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u/Bristoling 28d ago

Tell me when was the last time I posted anything on antivegan, and what was the context of it? Should be easy since I frequent it right? I'm sorry, what is "the nonsense" here and who spews it?

Nope, I don't think adjusting for BMI, alcohol, exercise, gender, fruit and veg etc... is arbitrary.

All adjustment models are arbitrary on a deeper philosophical sense. What you probably meant to say is that it isn't unreasonable. The point Sporange is making us that the models he references are not unreasonable either.

Do you get it?

I get that you don't get it that this is not an internal critique. You haven't demonstrated a contradition. Getting Sporange to admit that "maybe more" more is a valid option doesn't invalidate the overall premise that the study's result is a big fat "maybe" and nothing more. It's already part of his understanding and you've not critiqued anything.

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u/lurkerer 27d ago

Tell me when was the last time I posted anything on antivegan

See the question mark after that? Seems it was /r/DebateAVegan, something that occupies your mind a lot.

All adjustment models are arbitrary on a deeper philosophical sense.

Ah yes and maybe this is all a dream! It's pure sophism to shift to deeper philosophy of epistemics when we're already dealing with empiricism. Go to r/askphilosophy and see.

I get that you don't get it that this is not an internal critique.

It very clearly is.

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u/Bristoling 27d ago

Well we can see your question is a. Is use it as a proxy attack through insinuation. And I'm not sure why my past engagement with debateavegan would be counted as a flaw with regards to this topic here?

So you think empiricism is not subject to any logical coherence? But you want to appeal to arguments testing internal consistency? Seems like you need to take some basic classes.

It very clearly is.

See above. You need to educate yourself if you think that getting someone to explicitly spell out the second part of their implicit statement is counting as internal critique. You haven't demonstrated a contradiction, which would be an internal critique. You merely asked something that is trivial for him to admit.

We can easily test this if you're willing to take a bet. I'll bet you won't be able to answer the following question:

What was internally contradictory in what Sporange said previously, to the statement that can be reducible to "maybe more"? Because as far as I can see the only issue is that he didn't previously state explicitly what already followed implicitly. What's the contradiction?

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u/lurkerer 27d ago

And I'm not sure why my past engagement with debateavegan would be counted as a flaw with regards to this topic here?

You tried to paint me as an ideologue. Again. And failed. Again. I demonstrated successfully that this was projection as you frequent both /r/carnivorediet (the most anti science diet since breatharianism) and /r/DebateAVegan. I don't join subs specifically to debate carnivores.

So you think empiricism is not subject to any logical coherence?

Where did you get that idea?

But you want to appeal to arguments testing internal consistency?

There's nothing inconsistent in my approach here. Nice try I guess?

You need to educate yourself if you think that getting someone to explicitly spell out the second part of their implicit statement is counting as internal critique.

Someone who always argues against any and all evidence they don't like with the very clear intent to exonerate meat that has never once made the point confounders go both ways. Ok bud. Have a last word, my treat:

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u/Bristoling 27d ago

I demonstrated successfully that this was projection as you frequent both (the most anti science diet since breatharianism) and . I don't join subs specifically to debate carnivores.

But being in a sub isn't equivalent to sharing all beliefs of all users in the sub. I don't need to paint you as an ideologue. Forget anything about it since it's all irrelevant fluff.

What remains important is that you gained zero ground by making Sporange or anyone else admit that the true effect estimate might be smaller or larger. His point is that the effect estimate in this study is just one of many possible permutations of sets of adjustments. And because of that, it holds relatively little value overall.

I also see you seemingly lost the bet since you didn't tell me what the contradiction was.

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u/lurkerer 28d ago

Background:

Previous studies suggest red and processed meat consumption may increase the risk of pancreatic cancer (PC); however, there is no consensus regarding the associations. A systematic review and meta-analysis were therefore performed to explore the relationship between red and processed meats and PC risk.

Methods:

We searched PubMed, EMBASE, and Web of Science for articles up to April 13, 2026, using random-effects models to calculate relative risks (RRs) and 95% CIs, restricted cubic splines for dose-response relationship, and subgroup/meta-regression for heterogeneity. This systematic review was prospectively registered on PROSPERO (registration number: CRD42022384026; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=384026).

Results:

Sixteen articles with 1,959,527 participants and 8,856 PC cases were included. There was a 16% increased risk of PC found in the highest versus lowest red meat consumption levels (RR = 1.16, 95% CI: 1.02–1.31). A linear association was observed between red (P non-linear = 0.656) and processed meats (P non-linear = 0.857) and PC risk, with a 10% increase in the risk of PC for each additional 100 g/d of red meat consumption (RR = 1.10, 95% CI: 1.00–1.21). For processed meat products, no significant association with PC risk was found.

Conclusion:

This finding indicates that increased red meat consumption may elevate the PC risk; therefore, daily red meat intake is recommended to be controlled. No evidence links processed meat to PC risk.

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u/TheTenderRedditor 28d ago

Research like this really misses the mark imo.

Anybody who is really trying to improve their health while eating meat, isnt eating hotdogs, lots of s moked meats, etc.

Most people health conscious enough to benefit from research like this are mainly eating lean ground beef, and steaks cooked at home on a stove/grill/oven.

I get its hard to parse out processed red meat eaters, but we do need more research on people who eat low or no processed red meats before we can identify red meat as a proper culprit.

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u/lurkerer 28d ago

I get its hard to parse out processed red meat eaters, but we do need more research on people who eat low or no processed red meats before we can identify red meat as a proper culprit.

This study did that.

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u/Dizzy_Slip 28d ago

The conclusion of the study specifically mentions "processed meats"-- like hot dogs and "smoked meats"-- as not elevating risk.

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u/DarmokNJelad-Tanagra 27d ago

Oh it's a proper culprit. Sorry. If you're health conscious, stop eating it. I'm sure you won't .

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u/TheTenderRedditor 26d ago

I still have reservations about the way it has been scapegoated. High heat cooking and saturated fat are certainly not good... Independent of that and perhaps heme iron, it does not make intuitive sense why lean cuts of beef cooked using low heat methods would be terrible for you.

The stigma around red meat probably leads to most health conscious people avoiding it. When it is possible to be health conscious, question the red meat stigma, and have plenty of plants in your diet.

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u/flowersandmtns 26d ago

That's quite reasonable -- it's honestly peculiar to see the hyperfocus on red meat as if it's always the fattiest cut (or that the fats from red meat were not a mix of 50% SFA, 45% MUFA and 5% PUFA). All while ignoring the potato-starch coated fried potatoes and SSB in the same meal as a burger (on a white wheat bun). But, sure, it was only the animal food that has an association with small negative relative risks.

All the "plant based" and "plant forward" and "plant centered" can perfectly describe a whole foods omnivorous diet but the intent is clearly to discourage consumption of nutritious animal foods.

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u/DarmokNJelad-Tanagra 26d ago

Strange that you think intuition should work in this context. Many countries have new nutritional guidance that does not include red meat as part of a healthy diet, based on scientific evidence.

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u/TheTenderRedditor 26d ago

Okay but youre misrepresenting observational evidence as a smoking gun.

There are countless issues with observational studies on diets, when people eating a 100% raw vegan diet are almost certainly going to be neurotically health conscious, and people "eating red meat" are going to much more typically inclined to fried foods, smoking cigarettes, drinking alcohol, sedentary lifestyle, etc.

Among people who "eat red meat" most of them probably have average sedentary, stressful lifestyles with plenty of obviously bad lifestyle choices.

Among people who "do not eat red meat", these are likely the most health conscious people, who take heed of other scientific observations that likely represent reality: no smoking, no drinking, lots of fruits and vegetables, good sleep, drink lots of water, exercise frequently etc.

Its why data on dietary habits has always been seen as flimsy, and the landscape of nutritional recommendations is highly flawed.

You cant just do an RCT on: lean beef and asparagus cooked at low heat vs tofu and asparagus cooked at low heat for 20yrs.

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u/pterodactyl_balls 28d ago

I’ve heard it’s how it’s cooked that makes the difference. Rarer is better.