Clams Histamine Information

Consumption of clams can potentially impact histamine levels, largely due to their protein content. The process of histamine formation happens when the bacteria in the food release an enzyme, histidine decarboxylase, that converts the histidine in the protein to histamine. Clams, similar to other shellfish, may contain high levels of this decarboxylase, particularly if they are old, improperly stored, or not cooked soon after they're harvested. This high level of decarboxylase can raise the histamine content of the clams and thus impact an individual's histamine levels after consumption (1). Additionally, certain ingredients often used in dishes containing clams, such as alcoholic beverages for cooking and tomato-based sauces, are among foods with a high histamine content. This could additionally amplify the histamine level, leading to higher histamine intake. Whilst clams and some of their dish ingredients might be high in histamine or histamine liberators, some ingredients can lower histamine levels. One such example is fresh herbs like parsley and thyme. These may help reduce histamine levels due to their quercetin content, a flavonoid antioxidant that has been shown to stabilise histamine-release cells (2). It's important to note that the impact of eating clams on histamine levels can vary significantly depending on individual factors, including a person’s tolerance to histamine, the freshness of the product, and cooking methods used. 1. Maintz, L., & Novak, N. (2007). Histamine and histamine intolerance. American Journal of Clinical Nutrition, 85(5), 1185-1196. 2. Weng, Z., Zhang, B., Asadi, S., Sismanopoulos, N., Butcher, A., Fu, X., ... & Theoharides, T. C. (2012). Quercetin is more effective than cromolyn in blocking human mast cell cytokine release and inhibits contact dermatitis and photosensitivity in humans. PloS one, 7(3), e33805.