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TNF-alpha: Inflammation, Chronic Diseases, and Genetic Susceptibility

Key takeaways:
~ TNF-alpha (tumor necrosis factor alpha) is an inflammatory cytokine produced by the immune system to fight off pathogens and cancer cells.
~ Chronic elevation of TNF-alpha levels is linked to autoimmune diseases, skin infections, gum disease, heart disease, depression, and neurodegenerative diseases.
~ Genetic variants can increase your susceptibility to chronically elevated TNF-alpha.
~ Understanding your genes can help you find targeted, natural solutions for chronic inflammation.

Members will see their genotype report below, plus natural solutions for elevated TNF levels in the Lifehacks section. Consider joining today 

What is TNF Alpha?

TNF-alpha (tumor necrosis factor alpha) is an inflammatory cytokine produced by certain immune system cells during acute inflammation. The main role of this cytokine involves signaling for ‘apoptosis’ meaning the cell needs to be destroyed. This is important both in fighting off a pathogen as well as in killing cancer cells.[ref]

Inflammatory signaling molecule: Calling in the troops

We think of redness, swelling, heat, and pain as inflammation, such as what happens after getting injured. However, the inflammatory response is also vital in fighting off bad bacteria, viruses, or fungi.

When the body needs an inflammatory response to fight off an invader, it releases inflammatory cytokines, such as TNF-alpha (and others).

When TNF-alpha binds to its receptor on the surface of a cell, two actions can occur:

  • One option is that it kills the cell. It’s like it pulls the pin on a grenade.
  • Another option is that it can also cause the cell to produce other inflammatory response molecules, but the cell still survives.

While cell death sounds bad, it is completely necessary to fight off certain infections — or if a cell is cancerous. Thus the “tumor” in tumor necrosis factor (TNF).

Wound healing:
Additionally, TNF-alpha is essential for the initial stages of wound healing. Inflammation is a necessary step for healing injured tissue.[ref]

Pathogen defense:
TNF-alpha is an essential part of the body’s initial defense against pathogens such as:[ref][ref][ref][ref]

  • Tuberculosis
  • Histoplasmosis
  • Malaria
  • Leprosy

Tumor Necrosis Factor α: Signal and Receptor

TNF-alpha is synthesized and released by activated immune cells – macrophages, lymphocytes, mast cells, and neutrophils. It is also produced as a transmembrane protein, as well as by smooth muscle cells in response to injury.[ref][ref]

After being released by a cell (e.g. mast cell or macrophage), TNF alpha can bind to several different receptors on the surfaces of cells.

The two main TNF-alpha receptors are TNFR1 and TNFR2. Most cells in the body have the TNFR1 receptor, but the TNFR2 receptor is more specific to immune system cells.[ref]

When TNF binds to a receptor, several different actions can occur, depending on the cell type and receptor type:

  • activates NF-κB, which is a transcription factor that controls cell survival and inflammatory response
  • activates the MAPK pathways, which are important in the cell cycle and preventing cancer
  • signals for cell death

How does TNF alpha cause inflammation?

The immune response is all about balance. You want to fight off pathogens with a strong response, but you don’t want a constant inflammatory response continuing when it isn’t needed.

Super fighter:
Genetic variants that increase TNF-alpha levels are linked to being better able to fight off pathogens, such as malaria or hepatitis B.[ref]

But.. That superpower of fighting pathogens and killing cancer cells comes with a price. For example, chronically elevated levels of TNF-alpha are linked with an increased risk of autoimmune diseases, skin infections, and gum disease.

Chronic inflammation in the body:
Several common genetic variants increase TNF-alpha levels and increase the risk of inflammatory conditions. Keep in mind that these same genetic variants that helped your ancestors survive leprosy or tuberculosis (and thus lived to pass on the variant to you), could be at the root of many of the inflammatory conditions that plague us today.[ref]

Higher TNF-alpha is linked to:

  • Rheumatoid arthritis (RA)
  • Psoriasis
  • IBD (ulcerative colitis, Crohn’s disease)
  • Skin infections
  • Gum disease
  • Asthma
  • Diabetic ulcers
  • Heart disease
  • Septic shock
  • Ankylosing spondylitis
  • Depression
  • Arthritis
  • COPD
  • Neurodegenerative diseases

Studies relate TNF alpha to chronic diseases:

Chronic inflammation in the body can be a driving factor in many inflammatory-based chronic diseases.

Examples of diseases caused by inflammation include:

  • Depression and mood disorders
  • Heart disease
  • Fibroids
  • Neurodegenerative diseases
  • Arthritis
  • Fatty liver disease (NAFLD)

Let’s dive into the research here:

Inflammation and Depression:

Recent research shows that, for some people, pro-inflammatory cytokines are at the heart of a major depressive disorder. For a subset of patients with depression, TNF alpha is elevated, and blocking TNF-alpha can ameliorate depressive symptoms. A 2008 genome-wide association study found that a TNF genetic variant increases the risk of depression.[ref]

Related article: Depression and Inflammation

Researchers think that inflammation, specifically high TNF alpha levels, impacts the HPA axis and elevates cortisol. HPA axis dysfunction is strongly linked to depression. Additionally, higher TNF-alpha levels can cause increased uptake of serotonin into cells, causing depressive symptoms.[ref]

Related article: HPA axis dysfunction and your genes

Heart disease:

TNF alpha is increased in heart disease, raising the question of whether heart disease causes an increase in TNF-alpha or whether higher TNF-alpha contributes to causing heart disease. To answer this question, researchers turned to genetics. Studies show variants that increase TNF are causally linked to an increased risk of heart disease.[ref]

Related article: Genetics and Coronary Artery Disease

TNF and Uterine fibroids:

Uterine fibroids are benign tumors in the uterus. These are a common occurrence, with estimates ranging from 50-80% of women having fibroids at some point in their lives. The growth of the fibroids is thought to be caused by steroid hormones (estrogen, progesterone), growth factors, cytokines, and chemokines. Research points to TNF-alpha as the most important cytokines involved in fibroid growth.[ref]

Related article: Fibroids genes

Intestinal absorption is altered with high TNF-alpha:

Inflammation and high TNF-alpha levels in the intestines alter the ability to absorb nutrients.

For example:

  • High TNF-alpha levels decrease the receptor needed for the absorption of vitamin C (SLC23A1).[ref]
  • Short-chain fatty acids, such as butyrate, are important for colon health. High levels of TNF-alpha decrease the expression of transporters for butyrate (SLC5A8).[ref]
  • Phosphate absorption is decreased when TNF-alpha is high in the intestines. Low phosphate absorption can cause problems with teeth and bones.[ref]

Neurodegenerative diseases:

Alzheimer’s and Parkinson’s diseases are both linked to higher TNF-alpha production in the brain.

Research shows that microglia and astrocytes release TNF-alpha when activated, and this increases the production of amyloid-beta plaque, which is linked with Alzheimer’s disease. Additionally, amyloid-beta can activate microglia and astrocytes, further perpetuating the creation of TNF-alpha and other inflammatory cytokines.[ref][ref]

Related article: Alzheimer’s APOE genotype

Fatty liver disease:

Non-alcoholic fatty liver disease (NAFLD) is caused by increased fat stored in the liver. This can eventually lead to liver disease. TNF-alpha, as well as a couple of other inflammatory cytokines, are increased in fatty liver disease. Research using animals that were genetically altered to reduce TNF-alpha levels shows that TNF-alpha is a driving factor in fatty liver disease.[ref][ref]

Related article: Fatty liver disease (NAFLD) genes


TNF Genotype Report

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Lifehacks: Natural ways to inhibit TNF alpha

If you carry genetic variants related to higher TNF-alpha levels and have a related inflammatory condition, inhibiting TNF-alpha may help to reduce chronic inflammation.[ref]

Keep in mind the tradeoff between TNF-alpha as a response to pathogens and inhibiting TNF-alpha to reduce chronic inflammation. If you are at a higher risk for infections, talk to your doctor.

The rest of this article covers natural TNF inhibitors, lifehacks, next steps to take, and how to prioritize the solutions. It is for Genetic Lifehacks members only.  Consider joining today to see the rest of this article.

Member Content:

  Log In


Why join Genetic Lifehacks?

~ Membership supports Genetic Lifehack's goal of explaining the latest health and genetics research.
~ It gives you access to the full article, including the Genotype and Lifehacks sections.
~ You'll see your genetic data in the articles and reports.

Join Here


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About the Author:
Debbie Moon is the founder of Genetic Lifehacks. Fascinated by the connections between genes, diet, and health, her goal is to help you understand how to apply genetics to your diet and lifestyle decisions. Debbie has a BS in engineering from Colorado School of Mines and an MSc in biological sciences from Clemson University. Debbie combines an engineering mindset with a biological systems approach to help you understand how genetic differences impact your optimal health.