Inflammatory Cytokines and their Adverse Health Effects
A healthy inflammatory response is transitory: it arrives quickly, repairs the damage and dissipates. Chronic inflammation, in which the body remains in a widespread inflamed state, damages the body in a variety of ways. Chronic inflammation is linked to some cancers, and can be a symptom of others.
Inflammation is regulated by inflammatory cytokines. These are divided into two broad categories: proinflammatory cytokines, which encourage inflammatory response, and anti-inflammatory cytokines, which curtail it. Proper cytokine regulation manages the body’s inflammatory response. When outside factors upset the balance, inflammation becomes chronic and can lead to serious adverse health effects.
One of the most common chronic inflammation outcomes is allergies, caused by inappropriate immune responses to otherwise harmless stimuli. Constant inflammation can also make immune cells attack the body’s naturally-occurring gut flora, causing inflammatory bowel diseases, including ulcerative colitis and Crohn’s disease. Chronic inflammation can also cause rheumatoid arthritis, attacking the joints. Chronic inflammation can increase heart attack risk if it affects heart tissue, and lung inflammation can cause fluid accumulation and narrowing airways. Chronic inflammation may also be related to sleep patterns. A 2009 study, Sleep Duration and Biomarkers of Inflammation (Patel,) found people who slept either abnormally more or abnormally less than average had higher inflammation-related blood protein levels.
Too many inflammatory cytokines can wreak havoc on many body processes through their presence alone. They can alter the kidney’s function by altering potassium ions inside it, changing how the kidneys transport solutes and water.
Hyperinflammation caused by inflammatory cytokines is the leading cause of lung tissue destruction in cystic fibrosis. Cystic fibrosis patients become more infection-prone because their inflamed lungs can’t clear out bacteria. The highly inflamed lungs lead to asthma diagnoses in 40-70% of cystic fibrosis patients.
Scientists have also found a key link between inflammatory cytokines and obesity. Fat cells generate certain cytokines, and obese patients frequently have elevated cytokine counts. The more fat cells present in the body, the more inflammatory cytokines are created, causing chronic inflammation in obese patients.
Chronic inflammation has also been linked to a higher cancer risk for certain cancer types. Specific cancers connected to chronic inflammation include lung, esophageal, cervical and digestive tract cancer. A 2014 Harvard University study entitled Adolescent Body Mass Index and Erythrocyte Sedimentation Rate in Relation to Colorectal Cancer Risk (Kantor) found obese teenagers with high inflammation levels had a 63% increased colorectal cancer risk during adulthood than thinner teenagers.
Scientists say when immune cells begin producing inflammation, immune regulation deteriorates. This creates an optimal environment for cancer growth.
The 2010 study Immunity, Inflammation and Cancer (Grivennikov) showed inflammatory responses play decisive roles at difference stages of cancer development. Inflammation also affects the immune system’s response to cancer therapies.
“A role for inflammation in tumorigenesis is now generally accepted, and it has become evident that an inflammatory microenvironment is an essential component of all tumors, including some in which a direct causal relationship with inflammation is not yet proven,” Grivennikov said. “Many environmental causes of cancer and risk factors are associated with some form of chronic inflammation.”
A deeper understanding of the interplay between inflammatory cytokines, chronic inflammation and the resulting health risks thereof will help develop new prevention and treatment methods for certain cancers and other adverse health effects.