Histamine intolerance

Histamine intolerance is a nonstandardized term for symptoms attributed to an impaired ability to break down histamine from food, leading to a buildup that mimics an allergic reaction.

Proposed mechanisms center on reduced activity of diamine oxidase, the intestinal enzyme that degrades dietary histamine, due to genetics, gut disease, certain medications or alcohol. Reported symptoms include flushing, headaches, nasal congestion, hives, itching, stomach cramps, diarrhea, palpitations and fatigue, often after eating aged cheese, fermented foods, cured meats, wine or leftovers. Because these symptoms overlap with true allergy, mast cell disorders, irritable bowel syndrome and other conditions, the concept remains debated.

There is no validated diagnostic test; evaluation involves excluding food allergy and other causes, sometimes measuring diamine oxidase activity, and a supervised low-histamine elimination diet with reintroduction. Registered dietitians and allergists guide this process. No established evidence supports cannabidiol as a treatment for histamine intolerance.