In a healthy young person inflammation is meant to be swift, efficient and effective. It should also resolve in a timely manner. If you’ve ever sprained an ankle you can probably recall being amazed (or maybe slightly horrified) at how quickly it swelled up to the size of a grapefruit, softball or other common round object about two or three times the normal size of your ankle. After a few days of ice and keeping the ankle elevated the swelling receded and you could begin to see its bony outlines and several weeks later your ankle was back to its old self.
Your body’s inflammatory response is vital to your health and well being. Inflammation is an inseparable component of your immune system, so that whenever you experience an immune response it is accompanied by some degree of inflammation and likewise, when you experience an inflammatory response, whether it is a seasonal allergy or a sprained ankle, it happens through an immune reaction.
However, when inflammation persists and becomes chronic, overactive immune cells begin to degrade healthy tissues. Chronic inflammation, shows none of the dramatic outward signs of a sprained ankle, instead simmering behind the scenes. Generally, this occurs when environmental and lifestyle factors merge with certain genetic predispositions. Over time, an array of degenerative conditions can manifest, speeding the aging process and even shortening lifespan.
How Does Inflammation Become Chronic?
Air and water pollution, herbicides, pesticides and many common household chemicals are examples of pervasive environmental immune system triggers. Some of these are within your ability to control and some are not. Wherever you can, it is advisable to limit your exposure by avoiding using or coming into contact with these substances. Additionally, several lifestyle and other factors contribute significantly to the development of low-grade inflammation.
Diet and Inflammation
Good, unsaturated fats, i.e. fish oil, olive oil, walnuts and flaxseeds are beneficial because they contribute to healthy cholesterol levels, while bad, saturated fats from meat and dairy contribute to high or unhealthy cholesterol levels. These same good and bad fats also affect inflammation. Here, we see the same pattern, whereby, polyunsaturated fats quell inflammation while saturated fats exert an inflammation-inciting effect.
People who eat a diet high in saturated fats, such as the standard American diet, show higher levels of inflammatory markers than those who eat a Mediterranean, Asian or diet low in saturated fat. In a 2014 Vanderbilt University study, participants who kept their saturated fat intake to one-third of their total fat consumption along with equal parts monounsaturated and polyunsaturated fats experienced a significant decrease in levels of inflammatory markers measured in the blood.
Diets high in processed carbohydrates can cause inflammation by virtue of their blood sugar-raising effects. Frequent spikes in blood sugar trigger cause oxidative stress which damages cells and triggers the inflammatory cascade. In a clinical trial, participants with type 2 diabetes followed a low-glycemic diet. After only 30 days, inflammatory markers in their bloodstreams were measurably reduced.
And, while on the subject of low-glycemic, complex carbohydrates, a meta-analysis of 7 clinical trials found that a high-fiber diet reduced levels of the inflammatory marker C-reactive protein by as much as 54%.
Obesity and Inflammation
Overeating at even one meal causes a spike in immune activity and, with it, inflammation. Chronic overeating, therefore, leads to chronic inflammation. This happens because the majority of your body’s immune tissues are located around your intestinal tract, in part, because pathogens and toxins might be present in food. As a result, whenever you eat a meal, your body needs to be prepared to meet those invaders before they gain entry into your bloodstream. The larger the meal the larger the inflammatory spike.
Scientists have also learned, in recent years, that fat cells do a lot more than store extra energy. We now know that fat cells, particularly those located around the abdomen, busily communicate with surrounding organs through chemical signaling molecules that are meant to help your body maintain metabolic homeostasis. Some of those signaling molecules promote inflammation and when secreted into the bloodstream exert effects similar to the way endocrine organs function. If you accumulate too many fat cells, their collective effect tips the balance toward increased inflammatory signaling.
Stress, Anxiety and Inflammation
Stressful life events such as loss of a job, divorce, or death of a loved one are strong triggers of inflammation. Your brain evaluates these situations as threats to your well-being, which translates to internal fight-or-flight scenario which causes a heightened immune response. Stressful life situations that don’t resolve in a timely manner lead to chronic inflammation. Here again, it is important to manage life stresses to the greatest extent possible and, for persistent sources of stress or anxiety, to practice stress reducing techniques to help decrease your physiological response as much as possible.
Other Factors that Trigger Inflammation
Smoking, drinking alcohol, taking prescription or recreational drugs, sleep deprivation and food sensitivities are some of the other lifestyle and health factors that trigger low-grade inflammation.
Inflammation, The Self-Perpetuating Cycle
One of the added dangers of chronic inflammation is that it becomes a self-perpetuating cycle. Once cells die or become damaged by the infiltrating army of immune cells, their waste products and other signals indicating that cells are stressed and in need of help enter the bloodstream. The body responds by sending out more white blood cells to mop up the debris. To get those cells where they need to go the inflammatory response is triggered and the cycle of inflammation is perpetuated.
Diseases Associated With Chronic Inflammation
Low-grade inflammation is a major contributing factor in the most common degenerative and metabolic diseases that plague modern society, including:
Arterial plaque formation starts when inflammation activates white blood cells, causing them to stick to the inner walls of arteries, then burrow into the thin lining, where they attract and engulf lipid molecules and cause a cascade of events that impede blood flow, eventually block arteries to the heart, causing a heart attack or to the brain, resulting in a stroke.
The connection between inflammation and type 2 diabetes starts in the gut. Certain bacteria, present in higher levels in obese individuals, have been observed to stimulate fat cells to produce high levels of molecules known as cytokines which promote inflammation and also cause insulin resistance by blocking activation of insulin signaling receptors in the insulin producing cells of the pancreas.
Diseases such as Alzheimer’s, Parkinson’s and multiple sclerosis result from the slow, eroding effect, over time caused by chronic, low-grade inflammation in the brain and spinal cord that overwhelm the body’s ability to repair itself.
Aging Contributes to Inflammation
Not only does inflammation promote the aging process but loss of some of our normal homeostatic mechanisms due to the aging process also promotes inflammation. Several primary processes associated with aging have been found to contribute to age-related increases in inflammation, collectively termed “inflammaging”.
- As we age, our ability to dispose of the waste products of cellular injury diminshes. As a result, toxins and cellular waste accumulate causing oxidative stress. This shifts the immune system into inflammatory mode to try and deal with the increasing burden of cellular waste.
- The aging gut wall starts to lose the ability to keep out harmful waste products of the normal intestinal bacteria, allowing them to wander into the bloodstream where the immune system detects them and rings the alarm bells, again eliciting inflammation. As well, the mix of bacterial species shifts as we age, possibly allowing an overgrowth of species that are more prone to inciting inflammation.
- Mitochondria, the energy producing powerhouses inside every cell, begin to falter and drop off precipitously in number as we age. In doing so, they release potent inflammation-activating chemicals.
- Cellular senescence, an innate cellular response that suppresses cells from reproducing. Normally senescence has a cancer preventive effect and helps with wound healing by facilitating the inflammatory process. However, with aging comes an increase in senescent cells, and, consequently greater inflammation.
- Age-related decline in immune function leads to a shift towards a mild hyperexcitability of immune response.