Chronic Pain: A Gift Gone Bad
A new understanding of chronic pain makes inflammation an accessible target of treatment.
By David Hanscom, MD published November 3, 2020 - last reviewed on January 5, 2021
All living creatures survive by processing sensory input, avoiding threat, and gravitating toward rewards. The species that ignored or misinterpreted danger, after all, simply did not survive. Any threat, mental or physical, will elicit a total bodily survival response, which includes increased metabolism (more calories consumed), stimulation of defensive hormones, (adrenaline, histamines, cortisol), and activation of the immune system, which creates an inflammatory response
Acute pain is an important sensory input, and it is both protective and a gift. It triggers the nervous system to automatically guide your actions so as to avert damage. Having your pupils constrict in bright light, sweating if too warm, pulling your hand away from a hot surface—all are automatic protective responses triggered by acute pain.
There are numerous types of pain receptors dedicated to sensing specific features of stimuli (heat, cold, pressure, and more), but they all share one overriding purpose— to protect your tissues. Collectively, they compose the nocioceptive system. The value of acute pain can be seen in people who lack protective sensation in their limbs, a common consequence of diabetes—they are at risk of developing skin breakdown.
By contrast, there is nothing good to be said for chronic pain. It’s never helpful. The pain impulses firing through your brain are not reflecting any meaningful data from the environment. The system that is normally helpful and necessary to keep you alive is now creating severe misery. Suffering from chronic pain has been documented to have a similar impact on quality of life as terminal cancer.
Chronic pain is a complex process that evolves in several phases still under study. Pain is usually precipitated by an event that may or may not cause tissue damage. Whether it becomes chronic doesn’t seem to correlate with the severity of the injury.
As pain becomes chronic , the nervous system becomes sensitized. One study looked at brain activity in volunteers who had been suffering from chronic pain for more than 10 years and in those who had been in pain for less than three months.
A measured, uncomfortable pressure was placed on a thumb in both groups. In the acute group, one part of the brain lit up; in the chronic pain patients, five areas were active—indicating a 500 percent increase in sensitivity. Chronic pain always worsens over time—the reason why patients feel certain that something serious is being overlooked.
As with an athlete or musician learning a skill, pain eventually becomes inscribed and ritualized in the brain’s circuitry. The circuits are functionally permanent.
Sleep quality, anxiety, and anger markedly affect the perception of pain. Perhaps the most challenging aspect of human existence is our possession of language and consciousness. As a consequence, mental threats—whether unpleasant emotions, negative self-talk, or unacknowledged feelings—are processed by the brain in a similar manner as physical threats. Since we cannot escape our thoughts, the body is under relentless threat.
One consequence of such stress is stimulation of the immune system. The release of pro-inflammatory white blood cells sets up conditions intended to protect cells from acute threats, but under chronic conditions, the inflammatory agents damage cells, including neurons in the brain. The brains of patients in pain shrink (although they re-expand with successful treatment). The speed of nerve conduction almost doubles; you feel even more pain.
Knotty as the problem of chronic pain is, there are solutions. Somatic therapies capitalize on neuroplasticity to forge new brain circuitry. It’s also important to lower inflammation. Among the many ways to do so are exercise, play, and massage. One of the most accessible is an anti-inflammatory diet.
Two nutritional components are the object of extensive medical research for their anti-inflammatory effects. One is omega-3 fatty acids, especially abundant in fish oil. The other is curcumin, an ingredient in the colorful spice turmeric. Both are easily obtained nutrients available in concentrated form to pack a powerful biological punch against inflammation run amok.
Omega-3 fatty acids are long-chain polyunsaturated fats commonly found naturally in marine sources, notably cold-water fish. They are direct players in the cascade of pro- and anti-inflammatory signaling set off by injury or the threat of injury. They release powerful compounds, called resolvins, that protect against pain and resolve many other inflammatory conditions. Omega-3 fats are also critical to the formation and maintenance of nerve cell membranes. Fish oil is the most concentrated source of omega-3s.
Curcumin, the active ingredient in the spice turmeric, takes a different tack, fighting inflammation through its antioxidant power. By curbing oxidative damage to cells, it prevents the activation of inflammatory processes. A highly colorful pigment, curcumin is one of a class of chemicals (polyphenols) that naturally occur in plants, protecting them from solar radiation, fungal disease, and other kinds of damage. Studies have shown polyphenols to promote longevity in humans.