Long before COVID-19 put intense focus on the immune system, research into the wide effects of inflammation on human health was growing.
More than 10 years ago, research in the journal EMBO Reports found that while inflammation “[had] long been a well-known symptom of many infectious diseases,” research increasingly suggested that it was “also intimately linked with a broad range of non-infectious diseases, perhaps even all of them.”
What is inflammation? It’s normally a foundational immune response and takes place whenever the body is injured or identifies a foreign invader, like a pathogen. That’s acute inflammation. But in a culture where people constantly eat unhealthy food—which can look like poison to the body—or experience ongoing stress, be exposed to environmental toxins, or take problematic drugs, people can also suffer ongoing inflammation, also known as chronic inflammation.
When the body encounters a virus, bacteria, or toxin, or suffers an injury, it provokes the immune system to unleash inflammatory cells and cytokines. In acute inflammation, the process will end, but in chronic inflammation, symptoms like abdominal and chest pain, fatigue, and fever can persist and be linked to such conditions as asthma, Alzheimer’s disease, rheumatoid arthritis, cancer, and Type 2 diabetes.
Inflammation May Lurk Behind Many Diseases
According to EMBO Reports, it was cancer research that first highlighted the role of inflammation in disease progression. The role of inflammation in colon cancer was especially eye-opening, wrote the authors, because of its connection to the expression of “toll-like receptor 4 genes” (TLR4s) that trigger an acute inflammatory response that alerts the immune system to microbial infection.
The problem, observed the researchers, is that “bacteria are constantly replenished through food intake, and therefore cannot be permanently cleared by the immune system; this can lead to persistent chronic infection maintained by TLRs.”
Research now suggests that inflammation is not just behind cancer’s “initiation, promotion, malignant conversion [and] invasion,” wrote the authors, but also behind its “final metastasis.” It is sparked by “DNA damage caused by reactive oxygen species that are produced by immune cells.”
Other diseases are now linked to inflammation, including central nervous system conditions like amyotrophic lateral sclerosis or ALS (in which inflammation is thought to be involved in the death of neurons) and asthma, in which glucocorticoid receptors sometimes do not bind to corticosteroids and thus fail to mute immune response.
In rheumatoid arthritis, the inflammatory cells can attack joint tissues, leading to joint damage, pain, and deformities. And research in Frontiers of Immunology associates some depression with “increased inflammatory activation of the immune system affecting both the periphery and the central nervous system.”
How Is Inflammation Treated and What Can Patients Do?
When inflammation is due to physical injury, it can be treated with rest, ice, and wound care, says the Cleveland Clinic. In cases of viral or bacterial infections, it will pass with the resolution of the illness or “invasion” that triggered it.
Chronic inflammation typically requires lifestyle changes, but your doctor may prescribe anti-inflammatory medicines sold over the counter called NSAIDs (nonsteroidal anti-inflammatory drugs) or corticosteroid shots.
Many experts now feel that lifestyle factors are the real key to resolving inflammation.
“There is growing evidence that diseases with an inflammatory component can be treated through physical exercise, rather than pharmacology,” wrote the EMBO authors. “The positive effect of exercise on inflammatory processes has long been known.”
Lifestyle issues like carrying too much weight, smoking, drinking to excess, not dealing with stress, and not exercising can all contribute to inflammation.
Supplements to Combat Inflammation
Medical sources suggest several supplements help treat chronic inflammation, including:
- Vitamin A
- Vitamin C
- Vitamin D
- Fish oil supplements
- Anti-inflammatory herbs, such as turmeric, ginger, and garlic
Sometimes a little flavor can go a long way. When it comes to turmeric and its active compound curcumin, the EMBO authors write that clinical evidence suggests that the spice, endemic to Indian cuisine, has proven effective against inflammatory bowel disease, likely by “scavenging free radicals, increasing anti-oxidants, and influencing multiple signaling pathways.”
Additionally, those at risk of inflammation would do well to follow a Mediterranean diet and emphasize foods that have anti-inflammatory properties, including:
- Oily fish, such as mackerel, salmon, and sardines
- Leafy greens, such as spinach and kale
- Olive oil
By the same token, they should avoid fried foods and fast foods that can trigger inflammation, including:
- Cured meats with nitrates, such as hot dogs
- Highly refined oils and trans fats
- Refined carbohydrates, such as sugar, pastries, and white bread
Nutrients Are Key
Dr. Barry Sears, a leading expert on inflammation, wrote in the journal Frontiers in Nutrition: “The initial acute inflammatory response is protective as it alerts the immune system to respond to the injury. However, if the initial inflammatory response is unresolved, this leads to chronic low-level inflammation. This unresolved inflammation results in tissue damage that transforms the otherwise protective initial inflammatory response associated with many chronic disease conditions.”
To heal from such inflammation, wrote Sears, one must increase “diet-controlled nutrients or their metabolites to activate AMPK and enhance SPM.”
AMPK, or activated protein kinase, is a phylogenetically conserved fuel-sensing enzyme that is present in all mammalian cells. It helps cells manage their energy, especially from glucose and fatty acids. SPMs, or specialized pro-resolving lipid mediators, help lower inflammation.
In his writings, Sears has flagged three dietary approaches that can address inflammation and accomplish these goals:
1) Following a highly defined, calorie-restricted anti-inflammatory diet, since “calorie restriction has been the most successful therapeutic intervention to improve healthspan (defined as longevity minus years of disability) in virtually every species studied.”
2) Adding SPMs, which are hormones that control the resolution of residual inflammation. They are a “superfamily” of resolvins, maresins, and protectins, all of which will address inflammation, Sears writes. Our cells make SPMs out of polyunsaturated fatty acids. In layman’s terms, eat more omega-3 fatty acids.
3) Activating the master switch of metabolism, AMPK, which is controlled by the AMP (adenosine monophosphate, a nucleotide found in cells) and ATP (adenosine triphosphate, an enzyme found in all cells). This system sets in motion a broad cascade of positive gene transcription factors that switch metabolism from anabolic to catabolic to restore ATP levels, Sears observes.
Better insight and treatment of inflammation can have a critical effect on major diseases and milder conditions.
For example, researchers at Carnegie Mellon University attempted to link stress, inflammation, and the risk of infectious disease by looking at glucocorticoid receptor resistance, which is known to have a role in other inflammation-related diseases such as asthma.
“[The] inflammatory process upregulates immunity to the cold virus and is responsible for well-known cold symptoms such as increased mucus production in the nose,” notes the article in EMBO Reports discussing the study.
“The implication is that stress does not necessarily increase the probability of infection, but it does amplify the symptoms. This suggests that anti-inflammatory rather than anti-viral mechanisms might constitute the most effective remedy for many upper respiratory infections.”
The findings suggest a link between pro-inflammatory cytokine levels and the expression of symptoms, which should be good news for any patients dealing with inflammatory conditions. Why? Because, as the authors write, “there is … hope of establishing a common framework for understanding a variety of conditions previously considered to be unrelated, through the underlying inflammatory mechanisms.”