MCAS
20 Triggers of Mast Cell Activation Syndrome (MCAS)
Dr. Bruce Hoffman
March 4, 2024

In an effort to help you notice common MCAS triggers, below are 10 non-food and 10 food triggers that commonly provoke mast cell mediator release and can result in mast cell disease.

10 Non-Food Triggers of Mast Cell Activation Syndrome

If you’re struggling or suspect you have MCAS, it’s in your best interest to reduce your exposure to these common triggers and minimize your chances for mast cell disorders.

The 10 non-food MCAS triggers are:

  1. Extreme temperatures – either hot or cold
  2. Exposure to mold or Lyme disease and co-infections
  3. Emotional stress
  4. Insect bites
  5. Chemicals in personal products
  6. Medications that liberate histamine or block DAO
  7. Sodium benzoate –a common food preservative
  8. Airborne smells from chemicals or smoke
  9. Heavy metal toxicity – aluminum, mercury, lead, cadmium, bismuth and arsenic are known to be mast cell destabilizers
  10. Anesthetics

10 High Histamine Foods that Should be Avoided (MCAS Food Triggers)

Studies have shown that eliminating foods high in histamine and other triggers can significantly improve symptoms of mast cell activation. 10 highest histamine foods you can avoid are:

  1. Yeast and alcohol
  2. Dairy (especially fermented dairy like kefir)
  3. Gluten
  4. Fermented foods, especially sauerkraut, kombucha, miso
  5. Cured and smoked meats and fish
  6. Shellfish
  7. Citrus foods – lemon, lime, orange
  8. Vinegar
  9. Leftover and aged food – especially if left in the refrigerator and not frozen immediately
  10. Berries – strawberries, blueberries, raspberries

More information about histamine containing foods and following a low-histamine diet can be found here.

Conditions Associated with Mast Cell Activation Syndrome

Because MCAS is a chronic, multi-system, multi-symptom condition with an inflammatory theme, it’s been associated with a number of conditions and diseases, including:

  • Chronic inflammatory response syndrome
  • Irritable bowel syndrome
  • Gut dysbiosis – the gut is rich in mast cells and home to over 70% of the immune system. Parasites, bacteria, fungi, and parasites can all trigger gut mast cells.
  • Obesity
  • Diabetes
  • Asthma and allergies
  • Autism
  • Autoimmune diseases (such as lupus, rheumatoid arthritis, and Hashimoto’s)
  • Candida overgrowth
  • Celiac disease
  • Parasite infections
  • Skin conditions such as eczema and psoriasis
  • Food intolerances and allergies
  • Gastroesophageal reflux (GERD)
  • Infertility and endometriosis
  • Chemical and medication sensitivities
  • Postural orthostatic hypotension (POTS)
  • CIRS – exposure to mold mycotoxins is a potent stimulator of mast cell activation
  • Migraines
  • Depression
  • Fibromyalgia
  • Fungal infections
  • Tinnitus
  • Multiple Sclerosis
  • Cancer

In general, inflammation accompanies MCAS and most of its coinciding or associated illnesses. If you are struggling to get one of these illnesses under control, there’s a possibility MCAS could be causing further complications.

It’s a good idea to check for MCAS if you have any of the above conditions and vice versa.

Dr. Bruce Hoffman

Dr. Bruce Hoffman, MSc, MBChB, FAARM, IFMCP is a Calgary-based Integrative and Functional medicine practitioner. He is the medical director at the Hoffman Centre for Integrative Medicine and The Brain Centre of Alberta specializing in complex medical conditions.

He was born in South Africa and obtained his medical degree from the University of Cape Town. He is a certified Functional Medicine Practitioner (IFM), is board certified with a fellowship in anti-aging (hormones) and regenerative medicine (A4M), a certified Shoemaker Mold Treatment Protocol Practitioner (CIRS) and ILADS trained in the treatment of Lyme disease and co-infections.

He is the co-author of a recent paper published by Dr. Afrin’s group: Diagnosis of mast cell activation syndrome: a global “consensus-2”. Read more about Dr. Bruce Hoffman.