Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
5 Jan

What is Inflammation?

Inflammation is one of those words that people use without really thinking about its actual meaning. So today we’re going to take a bit of a break from the blood lipid series to cover inflammation. In later posts, I’ll dig deeper into how the inflammatory response works with stuff like exercise and heart disease, but for now, I’ll just get the basics out there.

Existence is suffering, according to certain schools of thought. I don’t know that I’d go quite that far, but I would emphatically state that anyone who spends a modicum of sentient time in the space time continuum we call existence is gonna experience some unpleasantness. A bump on the knee, a bacterial infection, an acute injury, a persistent illness, a death of a loved one, a broken heart. It’s a big and often angry world that doesn’t necessarily care about you, and something’s gotta give. When that happens and the sanctity of our bodies is interrupted by pain, injury, or illness, our bodies respond with inflammation.

There’s that word again: inflammation. It pops up quite often in our circles, usually playing either the starring role, absolutely killing it as a supporting actor, or stealing the show with a cameo appearance in some malady or another. Heart disease, obesity, depression, arthritis (and any  -itis, really), autoimmune diseases, insulin resistance – all classics worthy of accolades (although tonsillitis totally got robbed in last years Oscars), and all linked to inflammation, sometimes even causally. So inflammation must be terrible, right? It must be completely and unequivocally a negative trait, kinda like how our body evolved to manufacture cholesterol to kill us. What, didn’t you know that coronary heart disease confers a survival advantage?

Jokes aside, the fact that inflammation is a common, natural, innate response to injury/pain/illness/stress is a hint that there’s probably something necessary about it. It’s not some accident, nor is it our body hell-bent on making life miserable for itself. On the contrary: inflammation is our body’s way of saying it isn’t gonna take the affront of injury or illness lying down. It’s not a passive spectator totally reliant on the kindness of Pfizer and Walgreens and an ice pack to get it out of a jam. Although you wouldn’t think it, what with the barrage of altruistic allknowing medical experts and commercials both touting some essential pharmaceutical, our bodies can actually heal themselves. And the first responder, so to speak, is the inflammatory process. That’s right. Pain, swelling, redness, and that radiating sense of warmth that we feel at the site of an injury or illness don’t manifest by accident or for kicks. That’s inflammation, and it’s essential to our very existence in a world of hurt.

First up, acute inflammation.

The initial response to a pathogen or an injury is acutely inflammatory. In other words, it is brief, lasting several days or less. All sorts of things can cause an acute inflammatory response. Here are a few:

  • Trauma (punch, kick, golfball to the head)
  • Infection by pathogens (bacterial, viral)
  • Burn (sun, fire, seatbelt buckle on a summer day)
  • Chemical irritants
  • Frostbite
  • Stabbing/Cut/Laceration
  • Allergic reaction

Things happen pretty fast in an acute inflammatory response and involve several different players, including the vascular system (veins, arteries, capillaries and such), the immune system, and the cells local to the injury. First, something painful and unpleasant happens; choose one of the above injury options. Then, pattern recognition receptors (PRR) located at the injury site initiate the release of various inflammatory mediators, which in turn initiate vasodilation (or widening of the blood vessels). This allows increased blood flow to the injury site, which warms the site, turns it the familiar red, and carries plasma and leukocytes to the site of the injured tissue. The blood vessels become more permeable, thus allowing the plasma and leukocytes to flow through the vessel walls and into the injured tissue to do their work. Emigration of plasma into tissue also means fluid buildup, which means swelling. At the same time, the body releases an inflammatory mediator called bradykinin which increases pain sensitivity at the site and discourages usage of the injured area. These sensations – heat, redness, swelling, pain, and a loss of function – are annoying and familiar, but they are absolutely necessary for proper healing.

Allow me to explain why the four primary symptoms of acute inflammation are important:

  • Increased blood flow warms the injury and turns it red, which can be irritating and unsightly, but it also carries the guys – leukocytes – that will be cleaning up the injury site, mopping up pathogens, and overseeing the inflammatory process.
  • Swollen body parts don’t fit into gloves, are really sensitive, and don’t work as well as their slim counterparts, but a swollen finger is a finger that’s full of a plasma and leukocyte slurry and therefore on the road to recovery.
  • Pain hurts, but if an injury doesn’t hurt and it’s serious, you’ll keep damaging it because you won’t know not to use it.
  • Loss of function prevents you from using what could be one of your favorite body parts, but you don’t want to make it worse be re-injuring it. Besides, it’s only temporary.

These symptoms both indicate and enable inflammation (and, thus, healing), but what’s the deal with inflammation being linked with all those chronic illnesses – like obesity, heart disease, and depression? How does something normal and helpful go haywire and become implicated in some of the most crushing, tragic diseases of our time?

When inflammation becomes chronic and systemic, when it ceases to be an acute response, when it becomes a constant low-level feature of your physiology that’s always on and always engaged, the big problems arise. The inflammatory response is supposed to be short and to the point. I mean, just look at its responsiveness. Go twist an ankle (don’t, not really) and watch how fast it swells up and gets warm to the touch. It isn’t meant to be on all the time.

And because a big part of inflammation is breaking the tissue down, targeting damaged tissue and invading pathogens, before building it back up, the inflammatory response has the potential to damage the body. That’s why it’s normally a tightly regulated system, because we don’t want it getting out of hand and targeting healthy tissue. But if it’s on all the time, regulation becomes a lot harder.

All these inflammatory mediators and their effects are short-lived and require constant propagation to keep going. The only thing that keeps it flowing is sustained or subsequent injury to the site, so a little cut that heals in a couple days will need to get infected or reopened if the inflammatory cascade is going to continue. This usually doesn’t happen in developed countries. Wounds don’t fester, limbs aren’t hacked off because they got infected, and we don’t live with as many parasites as we used to. There’s no exogenous bacterial epidemic laying waste to the population by invading our bodies and stimulating an inflammatory response that never quite ends (although the Jaminets would suggest that persistent infections are more common than we might think). No, there must be another explanation. There’s got to be another stressor, or stressors, that are doing two things: inducing the inflammatory response and hanging around in the environment as a constant feature.

I’m going to fire off a few things that both induce inflammation and tend toward prevalence in developed countries. You let me know if anything sounds familiar to you.

See what I mean? Since we’re set up for acute stressors requiring an acute inflammatory response, all this other low-level, evolutionarily-discordant, superficially mild stuff throws us off and sets us up for a lifetime of chronic inflammation.

Anyway, that’s all for today. I hope it was a learning experience. If you have any questions about inflammation, leave them in the comments and I’ll try to work them into future installments. Take care and Grok on!

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. Not to step outside anyone’s comfort bubble, but I have a girly question that’s been bothering me for 18 years. I am a recent convert to the Primal living lifestyle. I’ve been on and off it, and finally now firmly on it, for a couple of years. I feel better and stronger and happier and more alert and awake when I’m on it, and I’m so happy to have found it. But the issue of inflamation creates a question about a normal and healthy natural cycle most of us women deal with each month. I have suffered from more painful and difficult cycles than most women throughout my life, and was even Rx’d anti-inflamatory meds when I was 15. If I work out, which you would think increases physical stress and mild damage to the body, I get an acute reduction in inflamation. It happens right away that the pain lessens and the swelling and bloating will go down. When I’m living Primal, I have MUCH easier cycles, largely because of less inflamation. But with the mechanics of what’s happening in my body (the whole uterine wall tearing away and all that), shouldn’t the swelling be the good inflamation helping my body to heal from the trauma? Shouldn’t it remain when I’m healthier? I’m certainly not arguing with being in less pain, but it doesn’t seem to track. Any thoughts?

    nashea wrote on January 6th, 2012
    • Hop over to the primal parent – good girl-issue posts there.
      (And you’re not alone: lots of women reporting easier, shorter, redder, more regular cycles on strict paleo.)

      Lauren wrote on January 11th, 2012
  2. Excellent post, Mark! I often find myself saying “you should avoid inflammation” to my friends but then have some difficulty explaining what inflammation is in an easy to understand way. This post was very helpful in that regard (^^)

    TokyoJarrett wrote on January 6th, 2012
  3. Thank you very much for this write-up. I frankly wondered what inflammation “meant” as far as inside the body, or exactly how it would be bad, and so on. Great work making it so I can tell other people what it is and why it’s bad when it persists.

    Joy Beer wrote on January 7th, 2012
  4. How about allergies? They certainly cause inflammation, right?

    Jerry wrote on January 7th, 2012
  5. I’ve always immediately iced my bumps and bruises to keep swelling down. Should I let the area swell so that the healing slurry can do its work? I was always under the impression that we evolved to swim in cold waters so ice was good for injuries.

    HMK wrote on January 8th, 2012
  6. Without any changes in eating or lifestyle I have gained 70 poubds over the last year is this caused by inflamation or is there something else wrong with me(50 year old man) thanks

    Louie wrote on January 8th, 2012
  7. This is all great to me, but how come NONE of my friends are willing to disconnect from society for a week???

    They INSIST on having their smart phones on a CAMPING trip!!!

    Rob wrote on January 9th, 2012
  8. I wonder if you have any remedies for achilles tendonitis? I have struggled with this problem on my right heel right where the tendon connects to the heel bone. been to a doctor, given some anti inflammatorys and told to rest and stretch. It has improved some but it is clearly still not normal and I really do not want a surgery which I am told is very risky. I am 53 and had this problem almost three years. Thanks

    kris kight wrote on January 9th, 2012
  9. this just may be me thinking this….but doesn’t it seem odd that many of the things on the list that cause inflammation come directly of the modern era? when you compare this with what kind of dangers we faced before we became so advanced, you can see that we have simply traded oranges for apples. with that said, i feel like somehow the Primal Blueprint and other such lifeways could not work without the modern era and all it’s particular drama (unhealthy stuff). we may have lived the primal lifestyle when that was all we had but we were light years away from understanding simple infections. now we know all about infections and such, but we live like crap. so maybe this was all meant to happen. i dont typically think in fatalistic terms but while trying to catch up on some older posts today i read this one and it just struck me. we have finally figured out (to a certain degree of which i am clueless) what makes our species healthy. we have known all along in many cases, but on the whole, have screwed this up for centuries. especially with this last one. i guess it was inevitable that our knowledge of health and the human body would catch up to our technology. and this comment has just made me think of even more questions….

    daniel wrote on January 9th, 2012
  10. Hi Heather
    I wanted to respond to your question on autoimmunity. I also have an autoimmune condition, hence my interest in paleo. To date I have not had success with it however I would say I am more “paleoish” than full paleo and plan on doing it 100% for the next 6 months to see if it can help.

    To get more info on autoimmunity see below:

    1.Google “success for those with autoimmunity” & marksdailyapple. There is a good discussion on the forum.

    2.Search for Dr. Terry Wahls on Youtube or Tedx talks and watch her video regarding her recovery from MS.

    For my diet over the next 6 months I plan to up my plant intake as Dr Wahls did. Change my protein sources, reducing chicken and pork and upping ruminant sourced protein. Also eating more “nose to tail” as opposed to just standard muscle meat. Upping intake of other sources of animal protein / fat eg bone marrow broth. I also plan to increase my sleep as I read somewhere that it’s all worth nothing if you’re not getting adequate sleep.

    I think us autoimmune people need to be our own guinea pigs. Lots of people have success on the primal / paleo diet. I have not as yet but I want to give it a good shot so at least then I will know definitvely whether it can help my case or not. I think it’s very important to continue to research and to ask people about their experiences and what they did.

    Hope you see this post and hope it helps!

    Aoife wrote on January 10th, 2012
    • Thanks! I’m going to look into that.

      Heather wrote on January 10th, 2012
  11. Mark:

    A much-needed post. Thank you.

    Question about the kind of inflammation caused by the stressors listed in the post:

    I’ve never understood exactly how that kind of inflammation presents. WHERE in the body is the inflammation, and WHAT exactly is it that gets inflamed?

    Example: Suppose someone has inflammation from the omega 3/omega 6 factors on your list, or from poor gut health. WHERE is the inflammation and WHAT is inflamed?


    Susan Alexander wrote on January 10th, 2012
  12. Turmeric ( Generoudsly Spice Food)…Coconut Oil ( Soothes Inflamed Gut)…Vitamin D(4000 IU)…:) !!

    firefly wrote on January 10th, 2012
  13. I am glad you posted this.

    I have sort of a question, sort of a statement in regards to my own experieces with acute inflammation.

    I broke my hand about a year ago. Given my age, the doctors told me it would take 12+ weeks to heal.

    They told me take as much pain killers & aspiring as I needed, even willing to prescribe some. Then they told me to ice it down to prevent the swelling.

    Guess what I did? I did the opposite!

    I used HEAT and ONLY HEAT on my hand. I took NO pain releivers at all (it really didn’t hurt that much). Oh, and I cut back my intake of coffee and increased my intake of beer (in the evening).

    My hand blew up like a balloon!

    (getting all the good stuff to the damaged site… cool!)

    My hand healed in less than 6 weeks, the time they told me it would heal had I been a teenager!

    I have had similar experiences as an Ultimate Frisbee player. I sprained my ankles about ~25 times (I have to play with ankle braces now).

    In a tourney, the ONLY way I made it through Sunday was with HEAT. Had I put ice on them, I would have LOCKED the joints!

    I have to wonder if it is HEAT treatment that is the holy grail?

    Why are the medicos so intent on bringing the swelling down?

    Seems to me, from the broken hand story, you actually WANT the reverse?

    Iluvatar wrote on January 15th, 2012
  14. Awesome post. Good information for everyone to read. Only if everyone can get on board and stop with the fast food and poor diets.

    Dave R wrote on January 16th, 2012
  15. inflammation is response to a stimulus. Its a protective response, – to remove the organism/ intial cause of cell injury (e.g., microbes & toxins)

    Sat wrote on January 22nd, 2012
  16. This is a great article, I am young at 23 but I have never learned this anywhere. Great information and bravo!…Thank you!

    Paul wrote on January 31st, 2012
  17. Paleo has a lot to teach us about proper foods/nutrition. When not eating tho, there were other other things that went with the caveman lifestyle.

    One was walking most of the day looking for something to eat, and with no shoes to wear, the walking was barefoot.
    Fast forward a few million years…..
    a new science is now emerging, named “Earthing”. Researchers tell us the ground caveman, and we, walk(ed) on is a boundless storehouse of free electrons, which barefootedly pass into our bodies,equalizing the body’s own electrical level with that of the earth, thereby countering the buildup of chronic inflammation so prevalent today.
    The ungrounded (and inflammatory) condition we find ourselves in today began in earnest after WWII when the shoe industry progressed from leather (conductive) to rubber and plastic non-conductive shoe materials.

    Google “Earthing”to tune into the details

    As a caveman P.S. > walking all day with plenty of bare-skin exposure gave him gobs of sunshine/Vitamin D
    ….another deficiency our modern ways lead us to

    Bill wrote on February 2nd, 2012

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