What foods should you not eat with MCAS?

October 16, 2025 •

4 min read

According to The Mast Cell Disease Society, many patients report symptom improvement with dietary changes, although triggers can vary from person to person. For those with Mast Cell Activation Syndrome (MCAS), understanding what foods should you not eat with MCAS is a critical step in symptom management.

Quick Summary

Many people with MCAS manage symptoms by avoiding high-histamine and histamine-releasing foods such as aged cheeses, processed meats, fermented foods, and alcohol, but triggers are individual.

Key Points

Identify Personal Triggers: Not everyone with MCAS reacts to the same foods; an elimination diet is key to identifying your unique triggers.
Avoid Aged and Fermented Foods: Aged cheeses, cured meats, sauerkraut, and alcohol are typically high in histamine and should be avoided.
Watch Out for Leftovers: Histamine levels increase over time, so fresh food is often better tolerated than leftovers.
Mind Histamine-Releasing Foods: Some fresh foods, like citrus, tomatoes, and spinach, can cause mast cells to release their own histamine, even if they aren't high in histamine themselves.
Consult a Professional: Working with a dietitian or healthcare provider is essential to ensure a nutritionally adequate and balanced diet during an elimination diet.
Limit Additives: Preservatives, artificial dyes, and flavor enhancers like MSG are common triggers for many with MCAS.
Focus on Fresh and Unprocessed: A core strategy is to choose fresh, whole, unprocessed foods to minimize dietary histamine exposure.

Understanding MCAS and Food Triggers

Mast Cell Activation Syndrome (MCAS) is a complex and often misunderstood condition that occurs when mast cells, a type of immune cell, release too many chemical mediators at the wrong times. This can cause a wide range of symptoms affecting multiple body systems, including dermatological, gastrointestinal, neurological, and cardiovascular issues. Diet plays a significant role for many individuals, as certain foods can either be naturally high in histamine or trigger the mast cells to release their own histamine. This article explores the categories of foods commonly reported as triggers and provides a practical guide for navigating dietary changes.

High-Histamine and Aged Foods

One of the most common dietary strategies for managing MCAS involves a low-histamine diet. Foods that have been aged, fermented, or stored for extended periods tend to accumulate higher levels of histamine as bacteria break down proteins.

Aged and Fermented Dairy: Avoid aged and hard cheeses (parmesan, cheddar, blue cheese), yogurt, kefir, and sour cream. Fresh, soft cheeses like mozzarella or ricotta may be better tolerated by some.
Fermented Vegetables and Condiments: Steer clear of sauerkraut, kimchi, pickled vegetables, and vinegar-based condiments like soy sauce, ketchup, and mustard.
Alcohol: All forms of alcohol, especially red wine and beer, are known triggers for many people with MCAS. Alcohol can also block the activity of DAO, the enzyme responsible for breaking down histamine.

Processed and Cured Meats

The processing and curing of meats involve methods that increase histamine content. Freshly cooked meats are generally safer, but even leftovers should be handled with care.

Cured Meats: Salami, pepperoni, sausage, bacon, and hot dogs should be avoided.
Smoked and Canned Fish: Fish that is canned, smoked, or marinated is typically high in histamine. This includes tuna, mackerel, herring, and anchovies.
Leftovers: Histamine levels increase significantly over time in cooked meats and fish. Freezing freshly cooked food immediately can help mitigate this, but avoiding leftovers is a common strategy.

Histamine-Releasing Fruits and Vegetables

Some healthy, fresh foods contain compounds that cause mast cells to release histamine, making them potential triggers even if they don't contain high histamine levels themselves.

Fruits: Common culprits include citrus fruits (oranges, lemons), strawberries, avocado, pineapple, papaya, bananas, and dried fruits.
Vegetables: Tomatoes and tomato-based products, spinach, and eggplant are frequently cited as problematic.
Additives: Food preservatives, artificial colors, and flavorings (including MSG) can also trigger mast cell degranulation.

Other Common Triggers

Many other foods and ingredients can act as triggers, though reactions are highly individual.

Chocolate and Cocoa: Contains compounds that can trigger histamine release.
Nuts and Seeds: Peanuts, walnuts, and cashews are often listed among foods to avoid.
Spices: Certain spices like cinnamon, nutmeg, chili powder, and curry powder may be problematic for sensitive individuals.
Shellfish: Often associated with allergic reactions, shellfish can also be a significant trigger for those with MCAS.

A Comparison: What to Avoid vs. What to Eat Fresh

Working with a dietitian is highly recommended to create a balanced diet while managing symptoms. An elimination diet can help identify specific food triggers over time.


Food Category	Commonly Avoided (High Histamine/Releaser)	Potential Fresher Alternatives
Dairy	Aged cheese (cheddar, parmesan), yogurt, sour cream	Fresh mozzarella, cream cheese, ricotta (if tolerated), plant-based milks
Meat	Cured meats (salami, bacon), aged beef, leftovers	Freshly cooked chicken, turkey, and grass-fed beef
Fish	Canned tuna, smoked salmon, shellfish	Freshly caught and cooked fish (e.g., cod, trout)
Fermented Food	Sauerkraut, kimchi, kombucha, soy sauce	Fresh herbs, salt, safe vinegars (e.g., distilled white)
Fruits	Avocado, tomatoes, strawberries, citrus	Berries (except strawberries), melons, apples, pears
Vegetables	Spinach, eggplant, fermented vegetables	Leafy greens (except spinach), broccoli, carrots, bell peppers

Creating Your Personalized MCAS Diet

Managing MCAS through diet is a personal journey. There is no one-size-fits-all approach, and trigger foods can be unique to each individual. Instead of cutting out all potentially problematic foods at once, a structured elimination diet guided by a healthcare professional is the best path forward. A dietitian can ensure you maintain a nutritionally complete diet while identifying your personal triggers. The ultimate goal is to find a sustainable eating pattern that reduces symptoms without unnecessarily restricting your food choices.

It's important to remember that dietary changes are just one part of a comprehensive MCAS management plan, which should also include medical treatments as recommended by your doctor. Working closely with your healthcare team will help you find the right balance for your health needs. You can find more information from authoritative sources, such as The Mast Cell Disease Society, on navigating your diet with MCAS.

Conclusion

Managing MCAS effectively often requires navigating a complex relationship with food. While many common culprits include aged and fermented products, processed foods, and certain fresh fruits and vegetables, individual triggers can vary significantly. By focusing on fresh, unprocessed ingredients and carefully using a dietitian-supervised elimination diet, many individuals can identify and avoid their specific food triggers to significantly reduce symptoms. This personalized approach empowers you to make informed decisions about your diet and improve your overall well-being. Always consult with a healthcare professional before making significant changes to your diet to ensure it remains balanced and safe.

Visit The Mast Cell Disease Society for more dietary information

Frequently Asked Questions

With MCAS, the primary types of food to avoid are those high in histamine, such as aged and fermented foods, as well as those that trigger the release of histamine from mast cells, including certain fruits, vegetables, and processed ingredients.

Not necessarily. Individual triggers vary, and a low-histamine diet should typically be done as a supervised elimination diet to confirm which foods cause a reaction. Some people may be more sensitive than others, and not all high-histamine foods will affect everyone.

Leftovers can trigger MCAS symptoms because histamine levels in food increase the longer it sits after being cooked. To minimize this, it's best to consume freshly cooked meals or freeze leftovers immediately.

While not a substitute for dietary management or medical treatment, some foods are known to have natural antihistamine properties. These include apples, blueberries, and onions, which may help reduce inflammation.

Some fresh produce, like citrus, avocado, and spinach, are considered 'histamine liberators.' They don't contain high histamine themselves, but they can trigger your mast cells to release their own histamine, leading to symptoms.

The safest way to start an MCAS elimination diet is under the supervision of a healthcare professional, like a registered dietitian. They can guide you through a structured plan to eliminate potential triggers and then carefully reintroduce foods while tracking your symptoms.

Yes, many food additives, including preservatives (like sulfites), artificial colors, and flavor enhancers (like MSG), are known to be potential triggers for people with MCAS.

A trial period of about two to four weeks on a low-histamine diet is often recommended. If you experience no symptom improvement during this time, it may not be an effective strategy for you, or your triggers may lie elsewhere.