I’ve been meaning for a while to post a question here about the general idea in some quarters that “Food X promotes inflammation in the body” while “Food Y prevents inflammation in the body.” I’ve been putting off that OP for a while now – but today I read something that prompted me to kick it off.
I was reading this article in MacLean’s about ER staff burnout in Canadian hospitals. This paragraph got my attention:
The first COVID case I saw in the most recent wave was a woman in her 60s. She was triple vaccinated and didn’t present any respiratory symptoms. She had been nauseous for a week and nobody knew why she wasn’t eating or drinking. Her blood work was a mess: she had inflammation all over her body, and then our COVID test came back positive
That prompted my first, presumably simpler FQ: How does a blood test reveal general inflammation in a patient? What are the markers?
And just what is “inflammation all over (someone’s) body”, anyway? How does that manifest? Achy joints all over? Skin looks and feels reddened all over? Sore muscles all over? All of the above? I always conceived of inflammation as an acute thing: the redness around a flesh wound, a sore throat, pinkeye, swelling around a sprain – things like that. Diffuse “all over” inflammation is harder for me to conceptualize.
And now for the second, more complicated side question (which can go as a separate IMHO thread if an FQ approach is problematic): How firm, established, and accepted is the medical science behind inflammation-causing/preventing foods? Special anti-inflammation diets and all that? Total woo? Some woo, some firm facts? Totally grounded and scientifically established?
I understand there is something of a scientific frontier to this kind of nutritional research, and that not much of it is as settled as, say, the Copernican model of the solar system. But still.
‘Inflammation’ is not a very specific term, especially when describing simple direct observations. Someone could have apparent inflammation of different forms and causes.
It is a secondary condition to something that causes cellular injury, so claims that some foods reduce inflammation can be true and not mean much. Some foods are much less likely to produce allergic reactions than others, a diet of those foods could claim to prevent inflammation. Simpler advice would say don’t eat foods you are allergic to*.
Doctors could still observe inflammation all over a patient’s body. Muscle and skin inflammation, congested lungs, enlarged organs, could be observed directly and their could be some indications from blood tests as well.
*Apparently people need to be told not to take medications they are allergic to.
I, too, am curious about your other question. I’ve always vaguely assumed that sort of thing was woo, but it’s an idea that seems to come up more and more in mainstream journalism, not that that’s definite evidence it isn’t woo.
Besides the sedimentation rate test linked to by @Fretful_Porpentine, there’s the test for C-reactive protein that’s also an indicator of inflammation. My wife has rheumatoid arthritis, an autoimmune disorder that causes inflammation as it attacks joint tissue. The rheumatologist regularly runs both tests to understand how well the current program of medications is controlling the RA progress.
According to his personal chef, New England Patriots quarterback Tom Brady eats a highly restrictive, plant-based diet that centers on what he deems “anti-inflammatory” foods. Other foods, chef Allen Campbell explains, are off the table:
No white sugar. No white flour. No MSG. I’ll use raw olive oil, but I never cook with olive oil. I only cook with coconut oil. Fats like canola oil turn into trans fats… I use Himalayan pink salt as the sodium. I never use iodized salt.
[Tom] doesn’t eat nightshades, because they’re not anti-inflammatory. So no tomatoes, peppers, mushrooms, or eggplants. Tomatoes trickle in every now and then, but just maybe once a month. I’m very cautious about tomatoes. They cause inflammation.
What else? No coffee. No caffeine. No fungus. No dairy.
I mean, aren’t tomatoes, peppers, mushrooms, and eggplant about as generally healthy as a food can be? Olive oil verboten? Is all of that even halfway legitimate? Or maybe Brady, as an elite athlete, is determined to shave off every little tiny bit of extra inflammation – chasing small advantages for an edge, in other words. In a way regular Joes and Janes would never feel compelled to do.
Tomatoes can upset GERD. Tomato sauce can definitely upset gout. Sometimes my face gets a little flush when I eat tomatoes (I don’t have gout, just GERD) so they’re not benign, they do have some kind of effect on the body.
However, if you Google “tomatoes and inflammation” you get tons of articles that say “many people think tomatoes and other nightshades give you inflammation but studies show they don’t.”
So Brady is just buying into some bunk. However, he’s an elite athlete so the dude can eat what he wants.
I just recently learned that blood test can detect inflammation in the body. Been having some stomach issues and a blood test indicated some marker that something is out of whack. I had never heard of this before either.
Certain proteins in the the body tend to rise when acute inflammation occurs. These are called “acute phase reactants”. Some of these, like C-reactive protein, can be measured directly. Other indirect tests such as the erythrocyte sedimentation rate (ESR) may indicate whether the acute phase reactants are elevated. Unfortunately the tests are not terribly precise or specific.
Fever and white blood cell elevation (or lack thereof) are also not terribly reliable in many cases.
The study of both acute and chronic inflammation is very complex field in and of itself, and tests to measure such reactants should be ordered by someone who really knows how to interpret them.
Advice about “anti-inflammatory foods” should be taken with a grain of salt, or even more than a few grains (salt isn’t so bad for you).
The problem is that there’s little hard evidence on the subject. Much of it relates to research in lab animals and/or correlation with serum markers that may be associated with significant inflammation, but which are also (as Qadgop indicated) not very sensitive or specific and are prone to false positives.
“The underlying science…is somewhat shaky. Sure, plenty of foods have been found to reduce inflammation—many of them in laboratory experiments as opposed to in people: turmeric, blueberries, ginger, tea, various vegetables, dark chocolate, fish. University of South Carolina epidemiologists James Hébert and Nitin Shivappa valiantly surveyed 1,943 such studies and published in 2014 a Dietary Inflammatory Index, with 45 food elements. They created it as a research tool for evaluating diets but concede it’s built from studies that varied widely in methodology.”
"When I asked Ridker his views on anti-inflammatory diets, he grew uneasy. “This has caught on like wildfire,” he says, “but I have seen extremely little data that say this piece of food is ‘anti-inflammatory’ and this piece is ‘pro-inflammatory.’”
There’s also plenty of woo/hype on the subject aimed at getting you to buy certain products, books and diet plans which lack a solid evidence base.
If a medical profession told me that I had an inflamed liver, I’d take that seriously.
If a medical profession told me that I had inflamed skin, I’d take that seriously.
If a medical profession told me that I had an inflamed joint, I’d take that seriously.
But when I hear about just plain “inflammation”, all I hear is “wooo”.
Exactly what got inflamed?
“Fruits and vegetables, rich in flavonoids and antioxidants, have been associated with a lower risk of (low-grade chronic inflammation)-related diseases and low levels of some markers of inflammation (45, 46). Surprisingly, volunteers who had a large consumption of fresh fruits displayed higher circulating levels of IL-8, IFN-γ, and IP-10, compared to those with a moderate or low intake. Different studies suggest an anti-inflammatory role for polyphenols, elicited mainly through the modulation of NF-kB and MAPK pathways at multiple levels (46). However, clinical trials are somewhat contradictory, and in vitro studies have also reported an induction of IL-8 expression by resveratrol, a polyphenol contained in many fruits, thus opening new questions (46, 47). Moreover, IL-8 and IP-10 release may be induced by IFN-γ, whose increase could suggest an immuno-stimulatory effect of the fruit.”
That doesn’t mean fruit is bad for you, just that elevated cytokine levels may not reliably correlate with significant inflammation in the body.
Better throw out your apples, pears and plums, just in case.
The above quote mentions the paradox of resveratrol (a highly touted supplement, also found in some foods) inducing IL-8, a marker of inflammation. The all-time champion of resveratrol supplementation, Bill Sardi who promoted resveratrol (especially his company’s pill version) as a fabulous heart disease preventative, later suffered a heart attack.*
*Sardi, who described Covid-19 as “the greatest fraud ever pushed on mankind” died recently of what one source lists as sepsis associated with pneumonia/Covid-19.
I also think this kind of work is so much in its infancy that there’s very little useful info about the anti-inflammatory vs. pro-inflammatory nature of each of these cytokines and chemokines, and the interplay between them all.
I actually hope that COVID research can catalyze some of this work.
IOW: I hope they get a few bites at the apple
ETA: there’s a whole cohort of clinicians and researchers for whom this is Their Thing:
When I read that Maclean’s quote I see three separate clauses: blood work; inflammation; and COVID. I don’t believe it should be read as that the blood work indicated inflammation.
The doctor speaking was rambling on about his experiences, which got translated into an article. Some allowances for unplanned speech much be made. In a better setting he should have been asked to expand upon inflammation, but if the reporter was merely transcribing dialog there may not have been an opportunity.
Is there strong evidence that reducing inflammation is a good thing in and of itself? Inflammation is obviously a side effect of many medical problems, and fixing those problems will reduce the inflammation. But it does not follow that reducing inflammation itself is desirable; it may be the complete opposite.
All those claims about low-inflammation foods seems to be missing two major pieces–first, that the foods actually reduce inflammation; but second, that reduced inflammation is desirable in the first place.
The term “inflammation” is used in so many different ways that it is not that useful. Medical students learn that its signs include (among others) redness, heat and swelling usually due to increased blood flow and a large number of complicated chemicals. Many of these are part of the immune system and inflammation is a very complex topic, as is immunology, and they overlap greatly. We do not understand either as well as we would like.
Even in medicine, it means different things in different contexts. People who died of Covid often had a very severe systemic reaction, all over their body, which might be thought of as an excessive response by their immune system. Such a reaction mimics life-threatening allergies (again the same chemicals) and can cause severe problems including respiratory distress syndromes. Inflammation can be measured, there are several tests - none very helpful, as the results are often hard to interpret, rarely change pretest probabilities or decisions, and are almost never better than the history and clinical exam. Many things cause an increase in the things usually measured, so the tests themselves rarely add much value, even though they are often mentioned in woo literature.
Inflammation occurs by benign things like exercise where muscle grows after being stressed and damaged at a microscopic level. Inflammation occurs to increase blood flow needed to help your body fight off infections and insults. You might die without it, it is (like) the immune system. You need inflammation to survive.
As late as the 1850s, the average person died in their late thirties. It may be that the body prioritized not dying in infancy over more modern problems like cancers and heart disease which increase greatly in people over sixty. Inflamed organs generally just mean they are swollen and too large. “Inflammation” might well cause a lot of maladies and cancers. However, it is too simplistic a concept to be much use and these maladies are both very complicated and very different from one another.
There is some evidence that eating vegetables, using healthy oils and getting enough fivre, exercise, not smoking, avoiding sugars and excesses, etc. help people live better and longer. This is often taken to extremes by people with an interest in selling stuff or propagating woo. Most people should eat more fruits and vegetables and less processed foods. The reasons for this are complex and using the term “inflammation” is generally unhelpful, like the term “antioxidant”.
Reading the article and rereading the original post, I simplify what I wrote above.
“Inflammation over the body” is a systemic response seen in septic shock or other conditions which overwhelm and overactivate the immune system and its many chemicals. A Google search for “SIRS” (systemic inflammatory response syndrome) would list the many possible symptoms.
Blood tests for inflammation are, in practice, almost useless. In almost two decades of emergency practice, the only conditions where I give them any value at all are a few rare eye and rheumatologic conditions which are notoriously hard to diagnose. Woo books always ask you to go to your doctor to measure them. Don’t bother.
Eat more tomatoes. More fibre, vegetables, whole fruit, coffee and healthy oils. In general most things promoting anti inflammatory or antioxidants are woo. There are exceptions.
It is too early to generally recommend specific supplements of things beneficial in food, and this science is not well developed. Your body needs inflammation to grow and fight infection. Almost every chemical reaction involves oxidation and reduction (antioxidation). So what does that even mean?
