Low Histamine Diet: A Practical Guide for MCAS and Histamine Intolerance
Introduction
Mast Cell Activation Disorder (MCAD) and Mast Cell Activation Syndrome (MCAS) are conditions in which mast cells—immune cells responsible for releasing histamine and other mediators—become overactive. This can lead to inappropriate or excessive histamine release, resulting in a wide range of symptoms.
Histamine intolerance is a related condition where the body has difficulty breaking down histamine due to low levels of the enzyme diamine oxidase (DAO) or an overabundance of histamine-containing foods. For people with MCAS or histamine intolerance, consuming a diet high in histamine or histamine-releasing foods can trigger or worsen symptoms.
Common symptoms of histamine overload may include:
Flushing, hives, itching, rashes
Nasal congestion or sinus issues
Headaches or migraines
Dizziness or lightheadedness
Digestive complaints (bloating, nausea, diarrhea, abdominal pain)
Fatigue or “brain fog”
Palpitations or blood pressure changes
Anxiety, irritability, or sleep problems
Because histamine is found naturally in many foods—and increases as food ages—managing intake can help many patients feel better. Below is a food-by-food breakdown of what to avoid and what to choose instead.
Vegetables
Avoid (high histamine or histamine-releasing):
Tomatoes
Spinach
Eggplant
Avocados
Sauerkraut and other fermented vegetables
Better options:
Zucchini
Carrots
Broccoli
Cauliflower
Green beans
Sweet potatoes
Leafy greens like lettuce and kale (fresh, not wilted)
Fruits
Avoid:
Strawberries
Citrus fruits (oranges, lemons, limes, grapefruit)
Bananas (especially overripe)
Pineapple
Papaya
Dried fruits (raisins, dates, apricots)
Better options:
Apples
Blueberries
Pears
Mango (in small amounts, fresh)
Melons (honeydew, cantaloupe, watermelon)
Grapes
Meat, Poultry, and Fish
Histamine levels increase the longer proteins are stored—freshness is critical.
Avoid:
Processed meats (ham, bacon, salami, sausages, hot dogs)
Smoked or canned fish (tuna, mackerel, sardines)
Leftover meat that has been stored for more than 1–2 days
Better options:
Fresh chicken, turkey, lamb, or beef (cook or freeze immediately after buying)
Freshly caught white fish (cod, haddock, trout)
Freeze meat in portions right away to prevent histamine buildup
Dairy
Avoid:
Aged cheeses (cheddar, parmesan, gouda, blue cheese)
Fermented dairy (yogurt, kefir, sour cream)
Cream cheese
Buttermilk
Better options:
Fresh mozzarella or ricotta (if tolerated)
Fresh cream or milk (cow, goat, or sheep if tolerated)
Dairy alternatives such as oat milk, rice milk, or coconut milk (avoid those with additives that can trigger symptoms)
Grains & Starches
Avoid:
Fermented grain products (sourdough, yeast-heavy breads)
Highly processed packaged snacks with additives or preservatives
Better options:
White rice, brown rice, quinoa, millet
Gluten-free oats
Simple, fresh breads made without yeast (or flatbreads if tolerated)
Potatoes and sweet potatoes
Other: Alcohol, Leftovers, Condiments
Alcohol (avoid):
Red wine, champagne, beer (all are high in histamine)
Fermented liquors like whiskey and rum
Better choices:
Some tolerate small amounts of clear spirits like vodka or gin (but many need to avoid all alcohol)
Leftovers:
Avoid reheated meals kept in the fridge for more than 24 hours.
Freeze cooked portions immediately and reheat from frozen to minimize histamine buildup.
Condiments (avoid):
Vinegar (balsamic, red wine, apple cider)
Soy sauce, miso, fish sauce
Ketchup, mustard (especially aged/fermented varieties)
Better options:
Fresh herbs (basil, parsley, cilantro, thyme)
Olive oil or coconut oil for flavoring
Homemade dressings with lemon substitute (such as citric acid–free alternatives or a splash of fresh herbs and oil)
Final Thoughts
A low histamine diet can feel restrictive at first, but with planning, it opens the door to fresh, nourishing foods that reduce symptom flares. The key is freshness, minimal processing, and avoiding fermentation or aging. Because tolerance varies widely, it’s best to keep a food and symptom journal to identify personal triggers.
Always work with a knowledgeable healthcare provider or nutrition professional before making significant dietary changes—especially if you have MCAS, MCAD, or other medical conditions.
