The mechanisms I described in the previous post involve a process termed "central sensitization." Let me explain. The brain has a certain threshold at which it perceives pain. This threshold is variable, not absolute. In other words, there are moments when you have a lowered pain threshold and other moments when it is raised. For example, if you are in the middle of an athletic event, your pain threshold is elevated because of a change in your neuroendocrine milieu. A cut on your hand may not even be perceived until the game is over. You don't actually feel "pain" even though the pain signals are being actively generated at the tissue. While there are numerous places where this pain modulation occurs (spinal cord, brain stem, thalamus are a few...), it ultimately leads to a decrease in pain related activity in the brain.
"Central sensitization" is just the opposite. When a pain loop has been running for some time, your brain gets really good at perceiving and running that loop. This can happen after an injury where a vicious cycle emerges to perpetuate the pain.
These authors describe one model where a painful stimulus may...
"...induce multiple inflammatory and neuropathic processes in the spinal cord dorsal horn, and trigger modification and plasticity of local neural circuits. As a result, ongoing noxious signals to the brain are amplified and prolonged, a phenomenon known as central sensitization." Curr Pain Headache Rep. 2010 Jun;14(3):213-20.
Scientists are in agreement that this phenomenon occurs regularly. The question that remains unanswered (although we can make educated guesses), is whether or not central sensitization is more likely to occur when there is pre-existing inflammation in the brain or the periphery.
Does an unhealthy physiology have a greater probability of allowing central sensitization to occur? Does a person who eats well, has no inflammation, sleeps well, exercises regularly and manage his stress have a better environment that will resist the induction of these noxious pathways?
To be fair, we don't have a clear answer for this yet. The science pretty much says, "maybe- but we can't preach that particular message with full confidence." But when you consider the many health related "shades of gray" that brain can live in, when you consider our current understanding of pain physiology, when you appreciate the influence of food and nutrition on brain health and inflammation levels, it is not a giant leap of faith to believe that food is related to central sensitization.
If you know someone with chronic low back pain, I hope you are beginning to appreciate the absurdity of throwing multiple pain management modalities (ice, steroids, anti-inflammatory medications, exercises, physical therapy) at the individual without making fundamental changes to his diet.