Hi Friend,
If you are navigating the stormy waters of Mast Cell Activation Syndrome (MCAS)—or suspect you are—you know the terror of mealtime.
You eat. You react. You panic.
The logical response seems to be: Stop eating the things that hurt me.
It starts with cutting out gluten. Then dairy. Then high-histamine foods. Then salicylates. Before you know it, you are down to "The Safe Five"—perhaps just chicken, rice, and water.
Here is the hard truth that few people talk about: Extreme restriction before you are stabilised on proper treatment is one of the most dangerous things you can do for MCAS.
While it feels like you are protecting your body, you may actually be making your mast cells more reactive.
Here is why shrinking your diet to zero is a biological trap.
1. The Famine-Stress Response
Your mast cells are the sentries of your immune system. Their job is to protect you from threats. Do you know what the body perceives as a massive biological threat? Starvation.
When you restrict calories or macronutrients too severely, your blood sugar drops and your body enters a "famine state." To keep you going, your body releases cortisol and adrenaline.
The Catch: Adrenaline and stress hormones are potent triggers for mast cell degranulation. By not eating, you are keeping your body in a chronic state of "fight or flight," causing your mast cells to fire off chemicals even without a food trigger.
2. The Nutrient Gap (You Can’t Heal on Empty)
To stabilise mast cells, your body requires specific nutrients.
Magnesium and Zinc help stabilise cell membranes.
Vitamin C helps degrade histamine.
Vitamin B6 is essential for DAO enzyme production (which breaks down histamine in the gut).
If you restrict your diet to white rice and chicken, you are starving your body of the very tools it needs to calm the reaction down. You end up in a paradox where you are too malnourished to stabilise, but too reactive to eat.
3. Loss of "Oral Tolerance"
The gut is a "use it or lose it" system. Your microbiome and digestive enzymes adapt to what you eat.
If you cut out an entire food group (like fibers or complex carbs) for months while waiting for a doctor’s appointment, your gut bacteria shift. You physically lose the ability to digest those foods.
When you finally get treatment and try to reintroduce those foods, you will react—not necessarily because of MCAS, but because your gut has lost its oral tolerance. You have to fight twice as hard to get those foods back.
So, what should you do instead?
We know it is scary. However, the goal before treatment should be Nutritional Safety, not just trigger avoidance.
Don’t cut entire groups unless anaphylactic: If a food causes bloating or brain fog, try to keep it in rotation occasionally (micro-dosing) rather than eliminating it forever, to keep your tolerance up.
Focus on Nervous System Regulation: Often, reactions are amplified by the fear of the food. Calming the limbic system (brain retraining) can sometimes allow you to eat more foods than you think.
Prioritize Density: If you can only eat 10 foods, make sure they are the most nutrient-dense foods possible, not just the easiest ones to digest.
The Takeaway
Please do not try to "starve" the MCAS out of your system while waiting for a specialist. You cannot heal a body that is in a panic state over survival. You need adequate medical treatment, then we can start focussing on diet. The chances are once we treat the MCAS you will be able to eat a much more varied diet.
Be gentle with yourself. Nourish yourself as best as you can.
Stay Well
Dr Ahmed
Medical Disclaimer:
The information in this email/newsletter is for general educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any illness or condition.
This content should not be relied upon as a substitute for personalised medical guidance from a qualified healthcare professional who is familiar with your individual medical history.
Do not make any changes to your medications, supplements, or treatment plan without speaking to your doctor, pharmacist, or specialist.
If you have any concerns about new or worsening symptoms, please seek medical attention.
If you experience red-flag symptoms such as difficulty breathing, chest pain, severe allergic reactions, sudden neurological symptoms, or any medical emergency, please contact urgent medical services immediately.
Any suggestions shared here are informational, based on current evidence and clinical understanding, and may not be appropriate for every individual.
