Histamine excess may affect long Covid sufferers.

Histamine may be a familiar word for seasonal allergy sufferers. Anti-histamine medications may be used during pollen season for those with a itchiness and a runny nose. Others may have a year long sensitivity as the problem can also be genetic, due to less of the enzyme that is needed to breakdown histamine. The diamine oxidase enzyme, (DOE), is available as a supplement that can be taken with meals. (1)

We make our own histamine in response to allergy type sensitivities. Mast cells are part of the immune system that might become overactive and produce more histamine than we want during pollen season – or possibly after having experienced an infection such as COVID19. People experiencing odd symptoms months after seeming to recover from the worst of the respiratory and other symptoms of COVID19 may be experiencing excess histamine and mast cell overactivity. See this video for more information: Nicola Haseler interviewing Dr. Tina Peers regarding histamine and overactive mast cells after COVID19 recovery (LongCovid). (7)

Dr. Bruce Hoffman discusses Mast Cell Activation Syndrome – overactivity of the immune Mast cells in more detail. Lab tests for histamine, or other chemicals involved in the inflammatory response are not necessarily reliable and may require a refrigerated centrifuge, which may not be standard lab equipment. The problem may involve genetic susceptibility but not necessarily, anyone might develop symptoms given a combination of stressors. Emotional or physical stress, lack of sleep, and the foods we eat may over activate mast cells throughout our body or within the mucosal lining of the Gastrointestinal tract (from the mouth, already the way through). Someone with recent bowel illness, may have a short term reduction in the diamine oxidase enzyme needed to break down histamines in food. The enzyme is produced in the lining of the intestinal tract.

…we’re inundated, so to speak, with multiple stresses far more than our capacity to withstand them. Our immune system, it just gets triggered because of multiple stressors. And there are many triggers for mast cell activation. Poor sleep. Stress is one of the biggest triggers. Food, I mean, food is incredible in its ability to trigger the mast cells…” […] “So education is first. Second is to try and identify the triggers that trigger their mast cell activation. And this is one of the greatest challenges because there are many triggers from, you know, hot, too much heat, too much cold, stress, poor sleep, as mentioned. And then we get into the more obvious triggers, chemicals, heavy metals, dietary antigens, and then infections or inflammatory triggers like mold.” – Dr. Bruce Hoffman (8)

Family history may also be a factor, trauma for the person may have left them with an identity of illness; or trauma earlier in the family’s history may have left epigenetic changes. Changing diet and lifestyle, and pursuing health can be a lot of work, and which may even be resisted as the patient improves, (psychoneuroimmunology). Misdiagnosis of the physical problem as a somatization disorder (“it is all in your head”) may also be a problem according to Dr. Hoffman. (8)

The itchiness is not in my head – it is all over my body.

How do you even be a healthy person if you have never known health, nor has your family? What do people do all day? Go for a walk, without sneezing – cook delicious food that doesn’t leave you with a mystery headache later on – so many choices, but change can be difficult.

We also get some from foods that contain histamine naturally. Other foods may have increased content as it ages – fresh is best for people with histamine excess. (4) Freezing a larger batch of food in meal size portions might be a sensible way to prepare fresh foods (that don’t have food additives or seasonings that you need to avoid). Fermented foods such as yogurt, saurkraut and kombucha are popular currently, for the goal of improving intestinal health and the microbiome, (the balance of beneficial bacteria and other microbes within the GI tract). However they may make someone with overactive mast cells worse instead of better. Vitamin C may help. (8)

Avoiding foods that contain histamine or may increase our tendency to make more can help allergy sufferers or the people with the genetic difficulty breaking down the excess. Symptoms can include headaches as well as itchiness and runny nose. Fatigue may also be a problem as well as other odd symptoms or chronic pain. Anxiety and schizophrenia symptoms may worsen with excess histamine. (1, 3, 4)

There is plenty of information on the topic available so I will link to it rather than try to replicate it here. Several of the articles make the point that the problem is additive and histamine is not something you can avoid all together. Small amounts or a taste may be okay, but several foods or beverages over the course of the day may lead to an uncomfortable headache that evening. (3)

  • Amy Myers, MD, provides an overview of the food lists of foods to avoid, or consider eliminating and then adding back to check tolerance, a list of lower histamine foods, symptoms that may be linked to excess histamine, and a list of medications that may be increasing histamine, amymyersmd.com. (1)
  • People with histamine food sensitivities may also be sensitive to lectins, oxalates, and pesticides. Foods more likely to be low or high in histamines are also labeled with a code for lectin (L), oxalate (O), or pesticide residue ![food] on a website by Beth O’Hara, a Functional Naturopath, mastcell360.com. This includes the most extensive food list and includes seasonings and food additives to avoid, or which might be less of a concern to use. (2)
  • Brief list of symptoms that may occur, along with foods to avoid, and a sample day’s menu of lower histamine foods. (3)
  • Extensive list of symptoms or physical traits that may be associated with people with a lifelong sensitivity to histamine is included in this article about histamine. Mood problems of increased anxiety are not uncommon for people with histamine intolerance problems. Sleep problems may also be a concern. (4)
  • Tracking your symptoms and daily food is recommended by this site, histamineintolerance.org.uk; Food List: (5), the Food Diary is a downloadable link from this page: (6).
  • Medications, lab tests for diagnosis, and nutrients or phytonutrients that may help if the individual is not overly sensitive to them already are discussed in detail in the interview with Dr. Hoffman, audio or the transcript or available on Dr. Hedberg’s website: (8) . Dr. Hoffman also makes the very important point that an apparent ‘drug’ sensitivity might really be a reaction to other components of the tablet or capsule, or even contaminants, which is also something to look at on labels for other supplements and over-the-counter medications. Psychoneuroimmunology and the effects of trauma on the brain, and possible cognitive therapy approaches are also discussed in more detail.

Writing down your daily foods, beverages, and symptoms can be a good way to watch for patterns in what seems to make you feel better or worse. Food sensitivities can also vary with how much stress you are experiencing and whether you slept well, or drank enough water. Once you are more familiar with your patterns and know which foods and habits are helpful then recording your daily foods and symptoms may no longer be necessary.

Health is worth it. Happy dining, and good sleep to you!

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.

Reference List

  1. Amy Myers, MD, Histamine Intolerance: What You Need to Know, amymyersmd.com, https://www.amymyersmd.com/article/histamine-intolerance/
  2. Beth O’Hara, Low-histamine diet: How it can benefit you and what to eat, Low and High Histamine Foods Lists mastcell360.com https://mastcell360.com/low-histamine-foods-list/
  3. How to follow a low-histamine diet. Nov 13, 2018, houseofwellness.com.au, https://www.houseofwellness.com.au/health/conditions/follow-low-histamine-diet
  4. Histamine, histamine-sensitivity.com, https://www.histamine-sensitivity.com/histamine.html
  5. The Food List, histamineintolerance.org.uk, https://www.histamineintolerance.org.uk/about/the-food-diary/the-food-list/
  6. The Food Diary, histamineintolerance.org.uk, https://www.histamineintolerance.org.uk/about/the-food-diary/
  7. Long Covid + Histamine / MCAS – Dr Tina Peers in conversation with journalist Nicola Haseler. Oct. 16, 2020,
    nicola haseler, youtube.com https://youtu.be/vr2bb0b4X14
  8. Mast Cell Activation Syndrome with Dr. Bruce Hoffman, interview by Dr. Nikolas Hedberg, https://drhedberg.com/mast-cell-activation-syndrome-dr-bruce-hoffman/