Stress is pro-inflammatory. Stress alters how cortisol works. When you’re stressed, you have more cortisol in your system (to help you respond to all the tigers your limbic system thinks are about to attack you). When there’s chronically more cortisol in your system, your body tissues lose sensitivity to cortisol and then those tissues can’t regulate inflammation as they are intended to do.
In acute inflammation—the kind nature designed to help your body—the body accomplishes two goals: it creates a barrier to protect against the spread of infection from the injury, and it heals damaged tissues. Pain, redness, swelling, and warmth occur, often resulting in some loss of function. Even though the injury site may look as if something has gone terribly wrong, this inflammation process is designed to help your body.
Any injury will trigger an immediate and acute response, a short-term means of managing the situation. Let’s look at this with an old-style military battle analogy. (Last century. Modern warfare is something I have no understanding of.)
Imagine the setup
To begin, imagine the setup. First responders (white blood cells) constantly prowl through your bloodstream awaiting any attack from any direction. In addition to first responders, the bloodstream also carries fluid called exudate that can quickly be sent to any attacked location. Exudate is like the military supply water that carries everything necessary for a successful first response.
The enemy attacks!
The enemy attacks. Boom! Chemical mediators tell the nearest blood vessels to increase their permeability so that within seconds, exudate fluid and white blood cells can leak out of the blood vessel and quickly arrive at the scene of the attack. In fact, capillary (very small blood vessels) pathways are quickly built to the attack scene so that repair materials can be delivered. It’s as if the Army Corps of Engineers is building roads to the attack scene, but in this case it’s endothelial cells building capillaries and creating the pathways.
The first responders to arrive at any attack or injury are generalists, and as such, they devour all potential invaders. They aren’t looking for any particularly specific threat yet—they will take down anything that remotely looks like a threat. As these first responders are devouring enemy cells, exudate is also filling the injury site with salts and fluid to carry in repair supplies as well as to bring in more specific fighters. Blood flow to the attacked area is increased, and the body tissue surrounding the injury consequently begins to swell, stopping the blood flow and thereby keeping the fighting contained. This swelling traps enemy attackers so they don’t spread. Warmth (created by increased movement of the blood), redness and swelling are all results of the rush of fluid and blood cells to the injury site and their activities once they arrive.
Each defensive wave of fighters brought to the attack scene by the exudate is carefully orchestrated by a command-and-control structure housed in the immune system and staffed with excellent communicators, strategists, spies and analysts. They’ve received information from the first responders, describing what the attack looked like and what is required to fight a good fight. The immune command-and-control center sends out messenger cells called cytokines that are used to signal when to start inflammation and when to shut it down. Cytokines also help communicate how strongly to ramp up the attack (how much inflammation is needed).
Blood vessels leading away from the injury site are essentially sealed off, preventing the loss of cytokines and white blood cells and other healing molecules from the scene, as well as making escape more difficult for various microbes, etc. The area around the injury now has only one door open and the exit door shut. At this point the injury site is filled up with cells that can work to repair and rebuild tissue, as well as destroy infection.
This process can occur in minutes or hours and can last for days if necessary. It depends on how severe or lengthy the attack is.
Swelling is created to help
While exudate is creating swelling to trap the attackers, the special force teams are getting into formation. Complement is a group of proteins carried in the exudate that act together to initiate inflammation. It’s like a squad of Navy Seals. Specialized proteins link together in groups of nine. The ring-like link formed by complement is called a membrane attack complex, or MAC. I like to think of it as the MAC attack. MAC controls the movements in and out of the cell of substances like calcium ions, which contribute to cell death.
Other specialty fighters appear
Other specialty fighters appear. Lymphocytes (among them T cells and B cells) arrive to more specifically target enemy cells. Macrophages and monocytes march in, devouring enemy cells and assisting the body in even more specific attacks against the invaders. The immune system analysts take notes about microbes involved in the attack, updating the immune system’s memory files so if that particular kind of attack ever comes again in the future, a ready-made response can be more quickly deployed.
Then the body’s repair job is finished
Eventually when the repair job is finished and infection is no longer an issue, the body signals for the exit door to open. Then all the exudate—that healing fluid bursting with pro-inflammatory cytokines and macrophages—is released. Now that it’s no longer needed, the swelling goes away.
During healing, the body uses pain signals to help you act in ways that are protective to the injured tissue.
What we’ve seen so far in this military analogy are all the signs of acute inflammation (swelling, heat, redness and pain). Now you likely better understand the parts they play in healing. Of course, how well your body can achieve its ultimate goal of healing depends on how well your cells are able to regenerate, and what kinds of injuries that were sustained. Needless to say, this is dependent on your overall health.
Swelling, pain and warmth is useful in healing
I think it’s fascinating how swelling, pain and warmth are so very useful in healing, and not just an annoying part of the injury trauma. Often we mistake good health as equivalent to having no swelling, no heat and no pain in our bodies. So instead of addressing the causes of these signs of healing, we seek to get rid of the symptoms. We reduce swelling, heat and pain with anti-inflammatory medication; we lower fevers, we take pain relievers, etc. The natural bodily defenses, however, can be crippled by these misguided attempts. The body’s best defense troops were using inflammation to solve an injury problem, and now they have been artificially denied this method. It’s similar to the military’s being grounded and not allowed to fight back. Without inflammation, the body is simply not as capable to efficiently kill microbes or heal from injury.
Stopping the symptoms isn’t always helpful
When we learn to better understand what the body is doing, we see that some of our conventional “stop the symptoms” responses to problems (for example trying to immediately reduce swelling or lower a fever) may not always be as helpful as we think.
Many Americans are getting on board with the idea that inflammation is a root problem that underlies most (perhaps all) chronic disease. Certainly there is a wealth of research that now supports the role of inflammation in disease states such as heart disease, Type II Diabetes, Multiple Sclerosis, Alzheimer’s disease, bowel diseases and even dental decay. However, the standard response in much medical practice is still to look for a Magic Bullet solution, a panacea in a pill. Statins, for instance, are an anti-inflammatory solution that have been advertised to lower cholesterol, but evidence of their unintended negative effects continues to mount. Another example is the baby aspirin many Americans have been advised for decades to take once per day as a way of lowering the risk of heart disease. Our Magic Bullet is that we think we just need to take an anti-inflammatory pill to fix the problem rather than resolve the multiple causes of systemic, chronic inflammation.
There is indeed a problem
It’s not as though our body is just imagining that there’s a problem and deciding to create chronic runaway inflammation for no good reason. There is indeed a problem.
It is the chronic inflammatory response that is problematic. When inflammation continues beyond its intended period of time, cell and tissue damage can result. Chronic inflammation can be a result of acute inflammation if the body can’t stop the injury. We mentioned cytokines—the messenger cells that signal both when to start inflammation and when to shut it down. It’s the imbalance in these two signals that can leave inflammation ongoing. Research has shown us how complex the interplay between acute and chronic inflammation is, but it might help to think of this complicated interplay as if it were disrupted communication on the battlefield between the attack site and the immune system’s command and control center.
Pro-inflammatory cytokines are messenger cells in our immune system that help kill invader cells (using oxidative chemicals such as hydrogen peroxide). They respond to signals to keep up the cell killing and the other pro-inflammatory activities. They also respond to signals that call for a “cease and desist.” When these cytokines don’t get a signal to stop, they can continue to kill cells in the body, and eventually the cells marked for death are not just invader cells. For example, cytokines might begin attacking cartilage in your knees, resulting in unchecked joint inflammation. You might try to resolve this situation with an anti-inflammatory medication, but you are only taking care of the symptom and not the root problem. There is an underlying reason the body is continuing to signal the presence of invader cells and continuing to release pro-inflammatory cytokines.
As another example, macrophages that are supposed to be deactivated by anti-inflammatory cytokines (messenger cells, specifically including interleukin 10 or IL-10 and transforming growth factor beta) are sometimes not deactivated and therefore continue to send out pro-inflammatory signals. Because the immune system is interdependent, one cell action can set off other cell actions. For example, when macrophages don’t get the message to stop, and continue their work of killing enemy cells, they also stimulate the activity of more fighters called lymphocytes, small white blood cells that include B cells, T cells and natural killer cells.
So, poor communication between vital healing components in the cells resulting in non-deactivated macrophages or cytokines, can be one path to chronic inflammation. Other paths include injuries that cause ongoing damage resulting in constant repair processes, persistent infections, toxin exposure or problematic autoimmune responses.
Excessive production of collagen
One example of the kinds of problems that can occur due to chronic inflammation is the excessive production of collagen tissue. Collagen is kind of like spackle—it’s a repair attempt of the body that can result in scar tissue when healing doesn’t fully occur. Did you know that scar tissue doesn’t always happen on the surface of the skin where it’s visible? Invisible scar tissue can interfere with the normal functioning of the surrounding tissue. It then becomes, to continue our military analogy, a barrier to good cell communications.
Damage to blood vessels
Chronic inflammation is particularly damaging to blood vessels. The endothelial layer of the blood vessel (the single thick cell lining inside the vessel) is what blood flows directly over, and is therefore very vulnerable to whatever is in the bloodstream. Some examples of substances that potentially damage the endothelial layers of blood vessels are: microbes, excessive blood sugar, low oxygen, high levels of acidity, and tobacco-related toxins. Obesity creates belly fat that produces its own inflammatory cytokines. Periodontal, or gum disease, also releases acids and infectious toxins from the mouth into the bloodstream. Even household cleaning supplies can trigger inflammatory responses. The resultant damage to blood vessels is a primary cause of heart disease.
Irritable bowel syndrome (IBS) is a term for a group of problems primarily involving abdominal pain, abdominal bloating and constipation and/or diarrhea. Until recently, medical science believed that IBS had no physical cause and was simply the result of patients’ becoming distressed about the functioning of their bowels. They were prescribed this or that medication (usually laxatives or anti-diarrhea drugs) and then shoved off on their merry way. But now physicians are starting to realize that IBS is a real disorder with physical causes. Nonetheless, the science underlying our understanding of IBS remains limited by what we can measure.
What we do know is this: The most common symptoms of IBS are abdominal pain, the relief of that abdominal pain with bowel action, passing mucous through the bowels and a feeling of incomplete evacuation. IBS typically flares up now and again and then it seems to go into remission. The average symptom flare-ups last about seven days per month with two bouts per day (lasting on average an hour each). Flare-ups are often associated with stress such as anxiety or depression, and some theorize that because of the mind-gut connection, flare-ups even cause anxiety and depression.
IBS is a very common problem and it’s actually the second most common reason people miss work, right after the common cold. At least 10-15% of the general population suffers from IBS, with some population estimates reaching as high as 20%.
IBS occurs more frequently in women than in men. The most common conventional treatments involve symptom management through either medication or lifestyle changes (things like eliminating dairy products or increasing exercise).
When initially diagnosed with IBS, many people receive the discouraging news from their doctors that they may be stuck with this misery for the rest of their lives. But data actually show that half of all IBS patients have recovered by their next follow-up visit. Also, resolving stressors (divorce, bankruptcy, etc.) helps some people with IBS to significantly improve, because the mind-body connection works both ways. It can help set off illness and it can also help resolve illness.
You can imagine that, during a bout of IBS, the affected person might be thinking “Why, oh why me?” as IBS sounds dreadfully miserable. Recent developments in science are indeed working on the question of “Why anyone?” As the connection between brain and gut becomes more apparent in study after study, it is easier to see how major stressors (mind) can impact the immune system (body). This connection is yet another clear example of why continuing to believe in the mind-body split is so last-century. Now let’s dive further into the details.