Inflammation: Your Immune System’s Response to Irritants
Inflammation seems easy to visualize. When a human is inflamed, they must be swollen, red, aching, and raw. Right? That’s how many anti-inflammatory diets promote the “soothing” and “calming” effects of the program on one’s tissues, skin, hair, nails, and joints. To understand this better, let’s take a closer look at what inflammation actually is. In the human body, inflammatory responses are governed by the immune system. Through a highly complex network of specialized cells and proteins that communicate to each other through chemical signaling pathways, the immune system defends the body against potential threats to its homeostatic health. Humans have both an innate immune system and an adaptive immune system that work to keep pathogens, or unfriendly organisms, out and to build resistance to future invaders. The innate system consists of a series of natural barriers such as skin and its acid mantel and mucosal barriers, and internal defenses such as phagocytes, natural killer cells, and antimicrobial proteins. The internal defenses are a network of cells and molecules that can ingest and eliminate threatening microorganisms. Phagocytes, such as neutrophils, ingest and eliminate pathogens. Natural killer cells puncture holes in cell membranes and induce apoptosis (cell death). Some of these immune cells can secrete pyrogens, a molecule that stimulates an increase in temperature, which causes the liver and spleen to sequester iron and zinc, which is needed by microorganisms, and increases metabolic rate, which increases the rate of repair. The adaptive immune system is the highly specialized defense response that targets threat with precision. Adaptive immunity is specific, systematic, not restricted to the initial site, and it has memory. The adaptive immune system utilizes cells called lymphocytes and antigen-presenting cells (APCs) to target specific invaders. As an example, a certain type of lymphocyte will have the ability to specifically produce the antibody for Influenza B. If Influenza B enters the body, it will be captured by an APC and then that APC will enter the bloodstream and lymph until it finds the single lymphocyte that “knows” that virus. When the APC finally finds that lymphocyte, it binds to it, triggering a chemical cascade that stimulates the lymphocyte to divide rapidly so that it can eliminate the Influenza B pathogen. Even after that lymphocyte has killed Influenza B, the cells will circulate the body indefinitely with a “memory” of the virus, waiting and ready to kill it immediately if it ever re-invades. This is how vaccines work. In tandem with these powerful cells that can protect and attack more specifically, the process also secretes potent messengers and signals, such as Interleukins—an inflammatory small protein that plays essential roles in the activation, differentiation, proliferation, maturation, migration, and adhesion of immune cells. The example of the flu virus highlights the need for inflammation. Inflammation is required for illness, broken bones, and protection. Modern humans have survived thousands of years of evolution by developing and benefiting from this powerful army housed within body tissues. Evolution selected for beings that were really efficient at getting transiently inflamed. If inflammation is the body’s response to some sort of an irritant, and the mobilization involves both specific and nonspecific defenses as well as potent signaling molecules, the nuance then lies in what triggers the defenses and when should they end?
Transient Inflammation
While inflammation may at first sound like something that should be avoided, research has shown that there is a difference between transient inflammatory events and sustained inflammation. It’s not just pathogens that would trigger a cascade; there are inflammatory responses to eating, exercise, and even stress. After eating, there is a need to cope with all the contents in the GI. Food entering the GI tract is certainly a good thing in many regards—as it supplies life-sustaining nourishment—but it nonetheless is an event that the immune system must cope with. Food consumption poses opportunities for consumed bacteria to enter the body, and prompts the immune system to prepare for such an event, as well as dealing with the increase in substrate (molecules in our food that are ultimately used for cellular energy). Similarly, exercise induces transient inflammation, but reduces systemic inflammation over time. Exercise is a stressful stimulus that can create an acute inflammatory event—with the activation of immune cells and uptake of substrate to heal the trauma on the muscle fibers. Yet over time, the reduction in fat mass decreases adipokines (fat cells that are metabolically active and known pro-inflammatory molecules) and systemic inflammation (Mora et al., 2007). The body’s goal is to return things back to homeostasis after receiving input that demands it cope with some irritant or stimulus. As can be seen with eating, exercise, or fighting off the flu, this inflammation can be beneficial.
Sustained Inflammation
The effects of sustained inflammation on the body is a major field of current research, with hallmark studies linking the state of chronic inflammation to dozens of seemingly unrelated diseases—such as heart disease, diabetes, neurodegenerative diseases, and cancers. At the core of sustained inflammation lies the concept of chronic overnutrition. Every time a person eats, their immune system (much of which is housed in the GI tract) must prepare for the onslaught of substances to filter, fight, and metabolize. Digestive organs must secrete hundreds of milliliters of digestive enzymes, and thousands of cells must work to filter, trap, protect, secrete, or absorb. If the food is filled with excessive substrate, that is, excessive calories and compounds to breakdown, the work is even more taxing. If many meals per day are inducing this process, and this occurs hundreds of days in a row, it’s easy to see where the tax of this process accumulates. Additionally, the content of the food itself can be inflammatory. Certain types of fats or glycemic loads can stimulate the pathways for the production of pro-inflammatory lipids and signaling molecules, such as Eicosanoids. In the standard American diet, the percentage of pro-inflammatory food consumed each day is incredibly high.
A body that receives far more energy than it needs, and doesn’t move enough to expend what it consumes, is going to be at risk of chronic inflammation. Not only is the process of coping with the onslaught of substrate taxing, but the increase in stored fat is also costly. Fat cells secrete inflammatory adipokines that signal immune cells. The more stored fat a body has, the more stress and activation of the immune system occurs.
Inflammatory Pathways Must Ebb and Flow
The trick to benefitting from inflammation and not suffering from it is to not overtax the system. Transient incidents of inflammation, therefore, are essential to human life. Muscles become inflamed after exercise, but then heal and become stronger. A broken bone gets repaired. Foods, when health-promoting and low in energy density, get digested and then pass through the GI. The ancient inflammatory pathways are beneficial for survival and building robustness. However, this tactful toolbox becomes pandora’s box if it is overused. Strategies for reducing risk of chronic inflammation include frequent, consistent exercise; receiving adequate sleep each night; avoiding consuming excessive calories; eating a diet rich in fresh vegetables and fruits, quality protein, and anti-inflammatory fats; and maintaining a healthy body weight. Fortunately, many recent studies have shown that pathologies can be reversed if inflammation is reduced. In 2016, researchers determined that there were statistically significant trends for decreasing mean plasma C-reactive protein (a reliable indication of inflammation) and concentrations with increasing consumption of Paleolithic and Mediterranean diet scores (Whalen et al., 2016). This data, in tandem with the known anti-inflammatory effects of exercise is a reliable strategy for achieving a healthy body weight and avoiding the perils of sustained inflammation. That way, all of the incredible abilities of natural killer cells, lymphocytes, and other immune factors can be left to deal with the true threats of our cellular environments.
The popular health media loves a good villain: carbs, sugar, fat, and dairy have all, at one time or another, been accused of ruining our health, making us fat, and ushering in a host of other physical maladies. Recently, the term “inflammation” has increasingly drawn the ire of celebrities and their trainers, and countless health gurus, stressing the importance of “anti-inflammatory” diets and products. But like many concepts that ride the waves of extreme popularity in the fitness industry, it’s difficult to actually break down the concept, understand it, and use that information for one’s benefit. So, what is inflammation? What causes it? And should a person try to get rid of all inflammation in their body?
Inflammation: Your Immune System’s Response to Irritants
Inflammation seems easy to visualize. When a human is inflamed, they must be swollen, red, aching, and raw. Right? That’s how many anti-inflammatory diets promote the “soothing” and “calming” effects of the program on one’s tissues, skin, hair, nails, and joints. To understand this better, let’s take a closer look at what inflammation actually is. In the human body, inflammatory responses are governed by the immune system. Through a highly complex network of specialized cells and proteins that communicate to each other through chemical signaling pathways, the immune system defends the body against potential threats to its homeostatic health. Humans have both an innate immune system and an adaptive immune system that work to keep pathogens, or unfriendly organisms, out and to build resistance to future invaders. The innate system consists of a series of natural barriers such as skin and its acid mantel and mucosal barriers, and internal defenses such as phagocytes, natural killer cells, and antimicrobial proteins. The internal defenses are a network of cells and molecules that can ingest and eliminate threatening microorganisms. Phagocytes, such as neutrophils, ingest and eliminate pathogens. Natural killer cells puncture holes in cell membranes and induce apoptosis (cell death). Some of these immune cells can secrete pyrogens, a molecule that stimulates an increase in temperature, which causes the liver and spleen to sequester iron and zinc, which is needed by microorganisms, and increases metabolic rate, which increases the rate of repair. The adaptive immune system is the highly specialized defense response that targets threat with precision.
Adaptive immunity is specific, systematic, not restricted to the initial site, and it has memory. The adaptive immune system utilizes cells called lymphocytes and antigen-presenting cells (APCs) to target specific invaders. As an example, a certain type of lymphocyte will have the ability to specifically produce the antibody for Influenza B. If Influenza B enters the body, it will be captured by an APC and then that APC will enter the bloodstream and lymph until it finds the single lymphocyte that “knows” that virus. When the APC finally finds that lymphocyte, it binds to it, triggering a chemical cascade that stimulates the lymphocyte to divide rapidly so that it can eliminate the Influenza B pathogen. Even after that lymphocyte has killed Influenza B, the cells will circulate the body indefinitely with a “memory” of the virus, waiting and ready to kill it immediately if it ever re-invades. This is how vaccines work. In tandem with these powerful cells that can protect and attack more specifically, the process also secretes potent messengers and signals, such as Interleukins—an inflammatory small protein that plays essential roles in the activation, differentiation, proliferation, maturation, migration, and adhesion of immune cells. The example of the flu virus highlights the need for inflammation. Inflammation is required for illness, broken bones, and protection.
Modern humans have survived thousands of years of evolution by developing and benefiting from this powerful army housed within body tissues. Evolution selected for beings that were really efficient at getting transiently inflamed. If inflammation is the body’s response to some sort of an irritant, and the mobilization involves both specific and nonspecific defenses as well as potent signaling molecules, the nuance then lies in what triggers the defenses and when should they end?
Transient Inflammation
While inflammation may at first sound like something that should be avoided, research has shown that there is a difference between transient inflammatory events and sustained inflammation. It’s not just pathogens that would trigger a cascade; there are inflammatory responses to eating, exercise, and even stress. After eating, there is a need to cope with all the contents in the GI. Food entering the GI tract is certainly a good thing in many regards—as it supplies life-sustaining nourishment—but it nonetheless is an event that the immune system must cope with. Food consumption poses opportunities for consumed bacteria to enter the body, and prompts the immune system to prepare for such an event, as well as dealing with the increase in substrate (molecules in our food that are ultimately used for cellular energy). Similarly, exercise induces transient inflammation, but reduces systemic inflammation over time. Exercise is a stressful stimulus that can create an acute inflammatory event—with the activation of immune cells and uptake of substrate to heal the trauma on the muscle fibers. Yet over time, the reduction in fat mass decreases adipokines (fat cells that are metabolically active and known pro-inflammatory molecules) and systemic inflammation (Mora et al., 2007). The body’s goal is to return things back to homeostasis after receiving input that demands it cope with some irritant or stimulus. As can be seen with eating, exercise, or fighting off the flu, this inflammation can be beneficial.
Sustained Inflammation
The effects of sustained inflammation on the body is a major field of current research, with hallmark studies linking the state of chronic inflammation to dozens of seemingly unrelated diseases—such as heart disease, diabetes, neurodegenerative diseases, and cancers. At the core of sustained inflammation lies the concept of chronic overnutrition. Every time a person eats, their immune system (much of which is housed in the GI tract) must prepare for the onslaught of substances to filter, fight, and metabolize. Digestive organs must secrete hundreds of milliliters of digestive enzymes, and thousands of cells must work to filter, trap, protect, secrete, or absorb. If the food is filled with excessive substrate, that is, excessive calories and compounds to breakdown, the work is even more taxing. If many meals per day are inducing this process, and this occurs hundreds of days in a row, it’s easy to see where the tax of this process accumulates. Additionally, the content of the food itself can be inflammatory. Certain types of fats or glycemic loads can stimulate the pathways for the production of pro-inflammatory lipids and signaling molecules, such as Eicosanoids. In the standard American diet, the percentage of pro-inflammatory food consumed each day is incredibly high.
A body that receives far more energy than it needs, and doesn’t move enough to expend what it consumes, is going to be at risk of chronic inflammation. Not only is the process of coping with the onslaught of substrate taxing, but the increase in stored fat is also costly. Fat cells secrete inflammatory adipokines that signal immune cells. The more stored fat a body has, the more stress and activation of the immune system occurs.
Inflammatory Pathways Must Ebb and Flow
The trick to benefitting from inflammation and not suffering from it is to not overtax the system. Transient incidents of inflammation, therefore, are essential to human life. Muscles become inflamed after exercise, but then heal and become stronger. A broken bone gets repaired. Foods, when health-promoting and low in energy density, get digested and then pass through the GI. The ancient inflammatory pathways are beneficial for survival and building robustness. However, this tactful toolbox becomes pandora’s box if it is overused. Strategies for reducing risk of chronic inflammation include frequent, consistent exercise; receiving adequate sleep each night; avoiding consuming excessive calories; eating a diet rich in fresh vegetables and fruits, quality protein, and anti-inflammatory fats; and maintaining a healthy body weight. Fortunately, many recent studies have shown that pathologies can be reversed if inflammation is reduced. In 2016, researchers determined that there were statistically significant trends for decreasing mean plasma C-reactive protein (a reliable indication of inflammation) and concentrations with increasing consumption of Paleolithic and Mediterranean diet scores (Whalen et al., 2016). This data, in tandem with the known anti-inflammatory effects of exercise is a reliable strategy for achieving a healthy body weight and avoiding the perils of sustained inflammation. That way, all of the incredible abilities of natural killer cells, lymphocytes, and other immune factors can be left to deal with the true threats of our cellular environments.