Understanding the Link Between Histamine, MCAS, and POTS
For individuals managing Postural Orthostatic Tachycardia Syndrome (POTS), diet is often a crucial component of symptom management. A significant percentage of POTS patients also have co-occurring Mast Cell Activation Syndrome (MCAS), a condition involving the excessive release of inflammatory chemicals, such as histamine, from immune cells called mast cells. When these cells overreact, the resulting histamine overload can exacerbate common POTS symptoms like flushing, headaches, tachycardia, and gastrointestinal issues. Consequently, adhering to a low-histamine diet can be a valuable strategy for mitigating triggers and stabilizing symptoms.
The Role of Mast Cells
Mast cells are a type of white blood cell that act as the body's alarm system, releasing chemical mediators in response to an allergic or inflammatory trigger. In MCAS, mast cells are hyper-responsive, leading to an inappropriate and widespread release of chemicals. Because histamine is one of the primary chemicals involved, high histamine levels can become a major issue for those with MCAS and POTS.
How Histamine Overload Impacts POTS
The symptoms of MCAS and POTS overlap significantly, making it difficult to differentiate which condition is causing which symptom. The excess histamine and other mast cell mediators can affect blood vessels, contributing to the cardiovascular instability seen in POTS. A buildup of histamine can also lead to gut issues, skin reactions, and fatigue, all of which are common complaints among POTS patients. For this reason, dietary management aimed at reducing histamine intake is a cornerstone of treatment for many individuals.
Primary Categories of High-Histamine Foods
High-histamine foods can be categorized based on their fermentation, age, or natural histamine content. A key distinction is between foods that contain histamine and those that act as "histamine liberators," prompting the body to release its own stored histamine.
Fermented and Aged Products
This category represents some of the highest histamine offenders due to the microbial processes involved.
- Aged Cheeses: Parmesan, aged cheddar, Swiss, and other hard cheeses develop high histamine content during ripening.
- Fermented Foods: Sauerkraut, kimchi, kefir, and yogurt contain histamine due to bacterial fermentation.
- Soured Products: Sour cream, buttermilk, and especially sourdough bread often have higher histamine levels.
- Vinegars: Red wine, balsamic, and other vinegars are fermented and should be used with caution.
- Fermented Beverages: Wine, beer, and kombucha contain significant amounts of histamine.
Processed, Cured, and Smoked Meats
Anything preserved or cured is likely high in histamine because of the breakdown of proteins over time.
- Cured Meats: Salami, bacon, hot dogs, and luncheon meats.
- Canned Meats: Preserved meats in a can.
- Aged Beef and Smoked Meats: Both processes increase histamine levels.
Specific Fruits and Vegetables
While most fresh fruits and vegetables are low-histamine, some are exceptions or act as liberators.
- High-Histamine Vegetables: Spinach, tomatoes, and eggplant contain higher levels of histamine.
- Histamine Liberators (Fruits): Citrus fruits, bananas, pineapple, papaya, plums, kiwis, and strawberries can trigger histamine release.
- High-Histamine Fruits: Avocado, especially when ripe, is considered high in histamine.
- Dried Fruits: All varieties of dried fruit contain more histamine than their fresh counterparts.
Other Trigger Foods
Several other common foods can also cause histamine reactions.
- Chocolate and Cocoa Products: Act as both histamine liberators and contain other biogenic amines.
- Certain Nuts: Walnuts, cashews, and peanuts.
- Shellfish and Certain Fish: Mackerel, tuna, sardines, and canned fish.
- Legumes: Chickpeas, soybeans, and lentils.
Histamine Liberators and DAO Blockers
Understanding these two categories is critical for those sensitive to histamine.
What are Histamine Liberators?
These are foods that don't contain high histamine but trigger the body's mast cells to release histamine. A person may feel fine eating a fresh food like an orange (low in histamine), but the fruit itself triggers a reaction because it acts as a liberator. Other liberators include uncooked egg whites and certain food additives.
Foods that Block DAO
DAO (Diamine Oxidase) is the main enzyme responsible for breaking down excess histamine in the body. Some foods and beverages can block the action of this enzyme, leading to a buildup of histamine. Alcohol and black tea are well-known DAO blockers.
The Impact of Food Preparation and Storage
Beyond the type of food, how it is handled and prepared significantly affects its histamine content. Freshness is paramount, while aging, processing, and long cooking times can increase histamine.
The Importance of Freshness
Histamine levels rise as food ages, especially protein-rich foods like meat and fish. The best strategy is to consume food as fresh as possible. This means buying fresh meat and eating it the same day, or freezing it immediately after purchase. For fish, ensure it is gutted within 30 minutes of being caught.
Cooking and Leftovers
Slow-cooking food at a low temperature can increase histamine content. Leftovers are another major source of histamine, as bacterial growth continues in the refrigerator. To manage this, it is recommended to freeze leftovers immediately after cooking instead of refrigerating them.
Processed Additives
Artificial colors, flavors, and preservatives often contain compounds that can act as histamine liberators or DAO blockers. Avoiding pre-packaged and highly processed foods is therefore a key step in controlling histamine levels.
High vs. Low Histamine Food Comparison
| Category | High-Histamine Examples | Low-Histamine Alternatives |
|---|---|---|
| Meats/Fish | Cured salami, aged beef, canned tuna, mackerel | Fresh chicken, freshly frozen trout, organic beef |
| Dairy | Aged cheese (cheddar, parmesan), kefir, yogurt, sour cream | Fresh mozzarella, cream cheese, goat or sheep milk products |
| Fruits | Tomatoes, strawberries, bananas, citrus, dried fruit, avocado | Apples, mango, white grapes, fresh cherries, pears |
| Vegetables | Spinach, eggplant, pickled vegetables | Carrots, broccoli, cucumber, sweet potatoes, cauliflower |
| Other | Alcohol, chocolate, cashews, walnuts, soy sauce, black tea | Herbal tea, carob, macadamia nuts, olive oil, rice products |
Managing Your Diet: A Cautious Approach
For those with a POTS-related histamine issue, managing your diet is a personalized process. Working with a healthcare provider, such as a functional medicine practitioner or a registered dietitian, is highly recommended to ensure you maintain a balanced diet and nutritional needs are met. An elimination diet can help you identify your specific triggers by systematically removing and reintroducing high-histamine foods. The key is to start simple and focus on fresh, unprocessed ingredients. For more information on MCAS and its relation to POTS, visit the PoTS UK website.
Conclusion
While not all POTS patients are affected by histamine intolerance, the significant overlap with MCAS makes it an important consideration for symptom management. By understanding which foods contain high levels of histamine or act as liberators, and being mindful of food freshness and processing, individuals can take proactive steps to control their dietary histamine load. This approach, when combined with professional medical guidance, can help reduce trigger events and improve overall well-being for many living with POTS.
