Mast cells can be activated by viruses. (2) People suffering with over activity of mast cells tend to not have very many colds or flu symptoms, even though they may have many other symptoms associated with the excessive inflammation and elevated histamine levels. Polyphenolic flavonoids are known to reduce mast cell inflammation and some have antiviral benefits such as luteolin. (2) Suppressing a mast cell response while trying to actively fight a viral infection would be limiting the body’s natural defense against a virus.
“A recent report correlated coronaviruses infection with activation of mast cells and subsequent cytokine storms in the lungs. 7 Mast cells are known to be triggered by viruses. 8″ Inhibition of mast cell‐associated inflammation could be accomplished with natural molecules, especially the polyphenolic flavonoids. 23 The flavone luteolin (not lutein, which is a carotenoid) has been shown to have broad antiviral properties.24, 25, 26” (2)
In Long Covid there may be residual virus but it is possible, maybe probable, that there is simply an overactivation of the mast cell system continuing to react to any food or toxin or even stress. See previous post.
“Colds and flu often last longer for people with Mast Cell Activation Syndrome or Histamine Intolerance. This is because these viral infections can set off a cascade of mast cell reactions lasting weeks or a few months.” (6)
Mast cell activation may vary based on what each individual is more sensitive to, as well as including some more typical problem foods or chemicals that everyone with overactive mast cells might find problematic. Symptoms can include a broad range and include mental health and behavior changes so diagnostic approaches might miss an inflammatory as the cause. See previous post.
Luteolin is found in celery, thyme, green peppers, and chamomile tea. (3) Some with over activity of mast cells might do better with the celery and thyme. Green peppers may be a mast cell/histamine problem food (4) and chamomile tea is a flower which some people with seasonal allergies (mast cell activation) may react to. See reference G10.12, Nrf2 Promoting Foods, chamomile tea is discussed and may be beneficial for people who are not sensitized to its pollen.
The excess Interleukin-6 that is commonly seen in COVID-19 illness may lead to over active mast cells in people who did not have seasonal allergy or Mast Cell Activation Syndrome symptoms for most of their lives (it can be genetic based). “Constant IL-6 exposure can cause the body to form more reactive mast cells.” (5)
The terminology and diagnostic criteria for mast cell over activity is still new. Some problems may include stimulation of mast cells without complete degranulation – release of histamine and other cytokines (IL-6 is a cytokine – a cell signal chemical). The name ‘Mast Cell Mediator Disorders (MCMD)’ has been established for symptoms involving less severe mast cell activity than full degranulation. (7)
How mast cell activation relates to Long Covid survivors may also vary based on personal genetic and other unknown factors in their environment or body burden of toxins (yes, we tend to contain a large mixture of modern toxins and heavy metals, (8)). Histamine containing or promoting foods could be a factor that varies based on a person’s diet and food sensitivities, in addition to mast cell activity throughout the body. Diet information and links were included in the first post about histamine in this series.
Based on the information about MCAS and histamine foods, I have improved my own odd symptoms and it is a huge relief to have found a cause that can be controlled, with some difficulty, and which explains the odd behavior and mood extremes. Histamine is involved in a wide range of brain functions and is involved in balance, not too much or too little activity – homeostatic control. Anxiety or whirling thoughts that only escalate are frightening and calling it a psychiatric problem wouldn’t help a histamine problem get any better. (Histamine’s function was included in the previous post.)
Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.
- Rafael Osswald, @RafaelOsswald, Tweet about research findings regarding crossimmunity in LongCovid survivors, Nov. 16, 2020 https://twitter.com/RafaelOsswald/status/1328408081487835152?s=20
- Theoharides TC. COVID-19, pulmonary mast cells, cytokine storms, and beneficial actions of luteolin. Biofactors. 2020;46(3):306-308. doi:10.1002/biof.1633 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7267424/
- USDA/Agricultural Research Service. “Luteolin stars in study of healthful plant compounds.” ScienceDaily. ScienceDaily, 16 July 2010. https://www.sciencedaily.com/releases/2010/07/100708141622.htm
- Hidden in Plain Sight: Histamine Problems, westonaprice.org, https://www.westonaprice.org/health-topics/modern-diseases/hidden-in-plain-sight-histamine-problems/
- Mast cells: MCAS, genetics, and solutions, geneticlifehacks.com, https://www.geneticlifehacks.com/mast-cells/ https://www.geneticlifehacks.com/mast-cells/#Other_substances_that_activate_mast_cells
- Immune Supports and Supplements that May Reduce Risk of Cold or Flu in Mast Cell Activation Syndrome and Histamine Intolerance. mastcell360.com, https://mastcell360.com/immune-supports-and-supplements-that-may-reduce-risk-of-cold-or-flu-in-mast-cell-activation-syndrome-and-histamine-intolerance/
- Theoharides TC, Tsilioni I, Ren H. Recent advances in our understanding of mast cell activation – or should it be mast cell mediator disorders?. Expert Rev Clin Immunol. 2019;15(6):639-656. doi:10.1080/1744666X.2019.1596800 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7003574/
- Gennings C, Ellis R, Ritter JK. Linking empirical estimates of body burden of environmental chemicals and wellness using NHANES data. Environ Int. 2012;39(1):56-65. doi:10.1016/j.envint.2011.09.002 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249606/