Category: Histamine & Food Tolerance

Histamine and food intolerances often overlap with methylation imbalances, particularly undermethylation. When methylation is inefficient, the body struggles to break down histamine through enzymes such as histamine-N-methyltransferase (HNMT) and diamine oxidase (DAO). As a result, histamine accumulates, leading to food reactions, flushing, headaches, congestion, digestive upset, anxiety, and sleep disturbance. Posts in this section explain how high-histamine foods—such as fermented products, aged cheeses, wine, vinegar, and leftovers—can worsen symptoms in those with low methylation activity. The Walsh Protocol recognizes undermethylation as a major contributor, since methyl groups are required to inactivate histamine. This pattern also correlates with low serotonin and dopamine activity, explaining why some individuals feel both anxious and fatigued after histamine-triggering meals. The approach emphasizes improving methylation capacity with SAM, methionine, zinc, and B6, while balancing gut flora and supporting DAO activity. Together, these steps help lower histamine load, improve food tolerance, and reduce inflammation-driven mood changes.