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Pass the bag of pain! Junk food as an inflammation driver

 •  • by Paul Ingraham
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For many years I have been encouraging pain patients to be as fit and healthy as possible as a way of improving long-term odds of getting pain-free. It’s possible that I have underestimated just how good that advice was — how strong and fast-acting, more like actual medicine.

This post is inspired by evidence from a new study by Elma et al.1 They didn’t produce the most robust data I can imagine, but it is intriguing, and it makes me want to instantly stop eating potato chips, just in case.

Product shot of a bag of "no name" brand potato chips: cheddar bacon flavour.

Bag of yum? Definitely (well, maybe if it was a better brand). Bag of pain? Disturbingly plausible. Although not as fast-acting as a poison that causes inflammation, a lousy diet might actually be able to cause pain in the relatively short term. But if that’s true, it’s also probably reversible.

Which is a tall order. I really like potato chips. But I would give them up for pain relief! (And obviously there are junkier foods than potato chips. They're just one very familiar example.)

Elma et al showed that people with back pain eat quite a bit more junk food, and have a lot more fat in their blood. This doesn’t necessarily mean that the poor diet actually caused their pain — but it might. It’s disturbingly plausible. The implication is that there wasn’t just a correlation between back pain and eating poorly, but the consequences of it: the high cholesterol caused by a poor diet might actually be directly inflammatory.

The long game versus short-term effects

I always thought a good diet was a smart long game for pain patients, but I never thought eliminating chips and beer was going to be a pain-reliever in the short term. It was more of a “rising tide lifts all boats” thing, a general and slow-acting tonic. I didn’t think junk food was inflammatory per se, “just” that it corrodes health in a way that makes pain likelier and nastier over time.

This new study encourages me to consider revising that in the best possible way: maybe we can reduce pain in the relatively short term by improving diet after all. Maybe it can happen about as fast as we can bring our cholesterol levels down — so roughly three months for most people.

Unless you have a genetic issue that keeps it high, like familial hypercholesterolemia, which affects about one person in 200 — yours truly being one of them.

More about the study

The researchers compared the diets of healthy people versus folks with unexplained chronic low back pain, about fifty of each. Everyone did a three-day food diary, filled out questionnaires, and had the pleasure of a going through a test for pain sensitivity (thank you for your sacrifice, study participants).

The diets of the back pain group were worse in every way. And they had more fat in their blood. And more inflammation. They also ate less of a few foods “known for their anti-inflammatory and antioxidative properties.”2

Three days of a food diary and a few dozen subjects with pain isn’t enough to prove anything (especially “causality”), and there are certainly some reasons why these results might not be quite what they seem. There are always sneaky confounders in diet and pain research, and it’s clear that there must be other variables in this equation — because obviously not everyone with high cholesterol has chronic pain, and not everyone with chronic pain has high cholesterol.

How this data fits into the bigger picture

The evidence may not be strong and it does not show causality, but it also isn’t exactly a big break with what we already knew. There is plentiful evidence that dysfunctional eating leads to metabolic syndrome over long periods, which is nearly synonymous with systemic inflammation … and so an obvious risk factor for pain. But that has always seemed like an indirect and delayed hazard, like the danger of eventually getting cancer from smoking.

This new evidence from Elma et al suggests that a terrible diet could be more of a clear and present danger: you could be hurting right now because you’ve been eating garbage recently. And if the cholesterol comes down, so might the pain. Not necessarily. But quite possibly. See also Bakshi, who reported in 2021 that dietary cholesterol is linked to pain sensitivity — again, not necessarily causally linked, but it’s certainly not a crazy idea.3

We must never forget that “correlation is not causation,” but we must also not forget that “it sure is a hint.”4 Causality is definitely possible here.

The implications are … healthy

The implication of the data is that pain patients should consider minimizing junk food. While I wouldn’t want to deprive suffering people unncessarily of cheap, easy, comforting foods, it’s not like you’re going to do yourself any real harm by eating better (especially as a temporary experiment). Compare and contrast this with the costs, risks, and shockingly low plausibility of so many other ways of treating pain! This one is extremely tame by comparison.

Three months to less fatty blood and less pain — if it actually works for anyone — is still not a quick fix by our impatient modern standards, but it’s sure a lot faster than “years.” Many people will read this and, just like me, immediately start looking at a bag of chips with deep suspicion. Like it might just be a bag of pain! Like it might make you more fragile in a season, rather than a decade.

Notes

  1. Elma Ö, Tümkaya Yılmaz S, Nijs J, et al. Proinflammatory Dietary Intake Relates to Pain Sensitivity in Chronic Nonspecific Low Back Pain: A Case-Control Study. J Pain. 2023 Aug. PubMed 37659446 ❐
  2. This result is a bit puzzling to me, since no food has ever actually been demonstrated to be significantly anti-inflammatory, nothing that you can eat that’s like popping an ibuprofen (either in the short term or the long term). I’d already be eating any such food! My guess is that this finding is there just because junk food eaters do not tend to go for those foods — and that’s a great example of a research artifact.
  3. Rahm Bakshi, Brooke Stansel, Larissa Strath, et al. Dietary Cholesterol is Associated with Increased Pain Sensitivity in Individuals with Chronic Low Back Pain. The Journal of Pain. 2021;22(5):588. PainSci Bibliography 51634 ❐
  4. The famous rule — “correlation does not imply causation” — is an important idea, but also a misleading oversimplification. At the very least it’s missing a word, and it should be “correlation does not necessarily imply causation.” Or you could just rephrase it entirely. Edward Tufte, an American statistician who made the same point quite a while ago, suggested that a good informal re-wording would be, “Correlation is not causation but it sure is a hint.” Because correlation actually does “imply” causation, and many (if not most) events that occur in sequence that appear to be causally related are in fact causally related. Their correlation is not a coincidence. Clapping makes noise, braking stops cars, hot coals burn fingers.

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