what is chronic inflammation?
Acute inflammation damages both good and bad cells alike, so the body keeps a tight check on it.
However, for reasons not yet well understood, certain triggers can disrupt the fine balance that regulates the inflammatory process, resulting in chronic, or ongoing, inflammation.
For example, when cortisol is released in just the right amount and for just the right length of time to stop the inflammatory process, this is a useful response.
However, when cortisol is released, it circulates throughout the body, not just at the site of injury, and if it travels systemically on a regular basis, it ends up hindering the immune system overall.
Not only will the continued presence of cortisol slow healing, but it will also heighten insulin resistance, leading to weight gain and negatively affecting brain cells that control memory.
In general, chronic inflammation is particularly bad for the heart and brain because the cells of these organs are very slow to regenerate when damaged, if they regenerate at all.
AILMENTS CAUSED BY CHRONIC INFLAMMATION
hronic, silent, or unproductive inflammation may be present in the body for years with no obvious symptoms. Think of it as a slow burn that goes unnoticed until considerable damage is done. Chronic inflammation follows the same process as acute inflammation, except it initially operates below the pain threshold and isn’t temporary. If left unchecked, chronic inflammation can lead to serious health problems.
Cancer.
Cancerous tumors secrete substances that attract cytokines (see page 3 ) and free radicals (see page 4 ), cells that cause inflammation, and use them to help the tumor survive. These substances also help loose tumor cells attach to new sites so they can grow and spread. When the body is already fighting inflammation from other causes, it can become fertile ground for cancer cell activity.
Diabetes.
High insulin levels increase the activity of a substance called enzyme D5D, which increases production of the inflammatory omega-6 fat arachidonic acid. Consequently, inflammation can compromise the activity of the endothelial cells that line blood vessels, making it difficult for insulin to access other cells and help them take in glucose, which in turn causes insulin levels in the bloodstream to rise. Inflammation then creates a link between diabetes and heart disease: insulin activates D5D, which creates more inflammatory arachidonic acid and blood vessel damage.
Heart disease.
Pro-inflammatory eicosanoids, such as arachidonic acid, can cause a plaque inside an artery to rupture, attracting platelets that could form blood clots and aggregate to create a blockage. They also could cause an artery to spasm. Inadequate levels of omega-3 fatty acids can lead to an irregular heartbeat, which contributes to heart attacks.
Alzheimer’s disease.
The brain doesn’t have any pain receptors, so we can’t feel the effects that chronic inflammation has on it.
Researchers have found that people with high levels of omega-6 fatty acids have a much greater incidence of Alzheimer’s disease.
In particular, the Framingham Heart Study showed that people with the lowest levels of circulating omega-3s had the highest rates of Alzheimer’s disease, although researchers don’t fully understand why.
There is also speculation about the connection between Alzheimer’s disease and diabetes; factors involved in insulin resistance also promote plaque development in the brain.
In some cases the immune response will turn against the body itself. Autoimmune diseases, such as lupus, rheumatoid arthritis, and type 1 diabetes, are actually forms of chronic inflammation. Common symptoms of autoimmune diseases are allergies, asthma, chronic fatigue, joint pain, skin problems (including eczema, premature aging, and wrinkling), and even depression. Allergies are a form of immune response to various substances that most people’s bodies would treat as harmless.
Chronic inflammation also contributes to and accelerates the aging process by prohibiting cell growth and regeneration.
A 2014 study conducted at the University of Bologna that was published in The Journals of Gerontology showed how chronic, low-grade inflammation is inevitable during the process of aging.
This relationship, called inflammaging, isn’t yet well understood, but scientists do know that the greater the measureable inflammatory response in an elderly person, the greater the risk of illness and death.
Gerontologists specializing in this area of research are currently exploring this association and testing promising treatments that might help reduce inflammaging.
One possible cause of inflammaging is the amount of cell debris that accumulates as people get older.
The body responds to cell debris as if it were a foreign substance, which in healthy individuals triggers macrophages that engulf and dispose of it.
As we age, the disposal process becomes less effective, but the continued presence of debris causes the body to maintain an inflammatory response in an attempt to remove these unwelcome substances.
Another potential cause is the action of the gut flora residing in the large intestine.
During the aging process, the large intestine becomes more permeable and less able to keep these mostly beneficial organisms from moving out of the intestine and into the body; this migration may trigger inflammaging.
It’s also conceivable the organisms themselves might change in ways that cause inflammation.
Healthy cells are coded to prevent them from growing out of control, as happens with cancer.
As cells age, this coding becomes persistent and prevents cell growth from occurring when it would be beneficial.
Preventing unwanted cell growth is part of the inflammatory response, so cells that persistently shut down growth also trigger additional inflammation.
Interestingly, cells that are signaling to slow growth are found in especially high levels in body fat, suggesting a link between obesity and inflammaging.
With age, blood coagulation capacity increases, which is also a part of the inflammatory response.
This tendency may be responsible for the increased risk of dangerous blood clots in elderly individuals.
The immune system may also experience the burden of a lifetime of toxic exposure, and parts of that system may decline while other parts become more active, contributing to inflammation.
An immune system that is defective or functioning improperly could also lead to macular degeneration, one the principal drivers of blindness in older people.
People who live exceptionally long lives, especially those who do so in good health, offer an interesting counterpoint to the observation that chronic inflammation and aging are inevitably linked.
The researchers involved with the University of Bologna study speculate that the usual methods for measuring inflammation might not be as accurate for predicting the potential for illness as was once thought.
A small amount of chronic inflammation may always be present in the body, not as a response to illness or injury but as a normal part of cell death and regeneration.
Also, some lucky individuals may have a genetic ability to create more of an anti-inflammatory response than other people do.
As a result, they might experience less inflammaging in their later years.
THE CAUSES OF CHRONIC INFLAMMATION
hronic inflammation is most commonly caused by exposure to toxins and poor lifestyle choices. As noted previously, it can also be a natural component of the aging process.
Lifestyle Factors
Fortunately, many causes of chronic inflammation are linked to harmful habits that are within our control. By understanding how these factors influence inflammation, we can make positive lifestyle changes to improve our health.
Diet
More causes of inflammation are related to diet than any other factor. Top on the list of harmful substances are refined fats, refined carbohydrates, and animal products.
Although carbohydrates and fats don’t contribute directly to inflammation, refined foods deliver a higher concentration of carbs and fats than is found naturally in foods. It’s thought that these higher concentrations adversely affect gut flora in ways that increase inflammatory factors. When the body is in the throes of chronic inflammation, refined foods will have an even greater negative impact on gut flora.
The types of fats a person consumes can affect inflammation in a variety of ways.
Before the advent of processed foods, the human diet had a nearly equal balance of omega-3 and omega-6 fats.
Most modern diets contain much higher amounts of omega-6 fats as opposed to omega-3s, and in some cases, ten to twenty times as much.
It’s important to ensure an adequate supply of omega-3 fatty acids because omega-6s and omega-3s compete for the same COX enzymes, which are enzymes needed to build larger fat molecules.
COX-2 enzymes in particular are essential for making inflammatory prostaglandins.
If too many omega-6 fats are consumed, they’ll dominate the use of these enzymes, decreasing the body’s ability to build anti-inflammatory fats from omega-3s.
Fats that have been chemically modified can also contribute to inflammation.
Early in the twentieth century, manufacturers sought inexpensive alternatives to solid fats.
Because liquid oils were cheap and plentiful, food chemists explored ways to alter the composition of these oils to create solids.
Their resulting discovery was what’s now known as trans fats, which manufacturers used to make vegetable shortening and margarine.
Unfortunately, no one realized at the time that the unnatural chemical structure of trans fats causes them to disrupt the normal flow of nutrients in and out of cell membranes and also allows harmful substances to enter cells.
In addition, trans fats interfere with the action of COX-2 enzymes, resulting in the production of cytokines that signal the need for inflammation to begin, along with the release of C-reactive protein to assist the healing process.
Fats are also chemically modified when they’re subjected to very high heat. When foods are fried, for example, toxic substances called advanced glycation end products (AGES) are created from both fats and proteins. After these foods are ingested, immune cells produce large amounts of cytokines in an attempt to protect the body from these harmful substances.
Animal products, especially meat and dairy products, contain higher amounts of pro-inflammatory essential fats, such as arachidonic acid, than whole plant foods.
In addition, these animal-derived items introduce more pathogenic microbes into the body, triggering an immune response.
Even when these foods are cooked at high temperatures or their pH is greatly acidified (such as by marinating them in lemon juice or vinegar), the toxins produced by the microbes they contain still exert an inflammatory load on the body.
Also, red meat contains a type of simple sugar called N-glycolylneuraminic acid (Neu5Gc) that the human body is unable to process because it lacks the necessary enzyme.
All other meat-eating animals carry this enzyme.
Consumption of foods containing Neu5Ge creates an immune response in humans that is linked to certain cancers.