Histamine intolerance occurs when the body struggles to metabolize and break down histamine absorbed from food. This difficulty often stems from insufficient activity of the Diamine Oxidase (DAO) enzyme, which primarily degrades dietary histamine in the digestive tract. Individuals managing this sensitivity must carefully evaluate common food items, including legumes like black beans, to manage their overall histamine load. The classification of black beans in a low-histamine diet is not straightforward, requiring a deeper look into their chemical composition and preparation methods.
Determining the Histamine Level of Black Beans
Black beans do not fit neatly into the category of high-histamine foods, which typically include items like aged cheese, fermented products, or cured meats. When freshly harvested, black beans are generally considered low in actual histamine content. However, the classification becomes more complex because black beans are frequently cited as “histamine liberators” or placed in a medium-risk or grey area. The challenge is not solely the amount of histamine they contain, but their potential to interfere with the body’s own histamine-clearing mechanisms.
The key issue lies in other naturally occurring compounds within the beans, specifically biogenic amines, which can mimic histamine effects. These compounds can compete with histamine for degradation by the DAO enzyme, effectively slowing down the body’s ability to clear histamine from other sources. Even if the black bean itself is low in histamine, its components can contribute to an overall histamine overload in sensitive individuals.
Why Histamine Levels Fluctuate in Legumes
The histamine content in any legume, including black beans, is highly variable and depends on two major factors: the presence of competing amines and the impact of microbial action. Black beans contain biogenic amines like putrescine and tyramine, which are structurally similar to histamine. When these competing amines are present in high concentrations, they can significantly inhibit the DAO enzyme’s ability to process actual histamine. Studies show that compounds like putrescine can dramatically delay histamine degradation, meaning the small amount of histamine consumed remains in the body longer.
The second factor is the inevitable increase of histamine levels during processing and storage due to microbial activity. Histamine is produced when bacteria break down the amino acid histidine, a process that continues after harvest. Canned black beans, which have undergone extensive processing and prolonged storage, typically have significantly higher levels of histamine and other amines than freshly dried beans. Furthermore, prolonged slow cooking or storing leftovers, even in the refrigerator, allows for the proliferation of histamine-producing microorganisms, causing amine levels to rise rapidly.
Preparing Black Beans for Low-Histamine Diets
For those who wish to include black beans in a histamine-conscious diet, using dried beans instead of canned is the first step, as canned varieties carry a higher risk of elevated amine content. The preparation process must focus on minimizing the microbial load and removing water-soluble compounds through extensive soaking and rinsing. Dried beans should be soaked overnight in fresh water, and the soaking water must be discarded thoroughly, as it contains leached biogenic amines. It is beneficial to change the soaking water two or three times during the process to maximize the removal of these compounds.
After soaking, the beans should be cooked completely, with pressure cooking often recommended as a superior method to slow cooking. The high heat and speed of a pressure cooker help ensure thorough cooking while limiting the time available for microbial growth. The most important rule for minimizing histamine load is to consume the beans immediately after they are cooked and cooled, as leftovers should be avoided.