This is one of the most frequently asked questions we get. In this blog, you’ll learn why vegan fermented vegetables do not contain relevant levels of histamine and which types of fermented foods can sometimes contain histamine.
Vegan fermented vegetables do not contain any relevant amount of histamine.
Fermented vegetables that do not contain animal-sourced and/or high protein ingredients do not contain relevant or detectable levels of histamine and are generally safe from biogenic amine concerns.
Also, histamine isn’t necessarily a bad thing. It gets a bad rep, but histamine is necessary for human body function. Histidine is an essential amino acid, and histamine is vital to the proper function of the immune system. Average, healthy people have no problem when consuming moderate amounts of histamine in foods. Good gut microorganisms normally degrade histamine in the gut, and the enzyme DAO (Diamine Oxidase) in the gut also degrades histamine.
Histamine Levels in Foods
So for instance, fish sauce averages HIGH histamine levels around 575 mg/kg. According to the FDA, levels of above 200 mg/kg (ppm) have been associated with human illness (histamine poisoning). So the “safe” limit set by the FDA is under 200 mg/kg of histamine.
The ingredients included in fermented vegetables, the fermentation method, the salt concentration, the fermentation temperature, and the amount of time it was fermented for all influence the levels of biogenic amines in fermented foods. With that being said, a lot of fermentation recipes incorporate animal products into things like sauerkraut and kimchi. People even make sauerkraut with whey added, and this can greatly increase the biogenic amine (histamine) levels. The only reason some kimchi contains relevant levels of histamine is that a lot of kimchi recipes include fish paste as an ingredient. Animal ingredients add the amino acid histidine to fermented foods, thus, they can add histamine.
Animal ingredients in fermented vegetables:
Fermented vegetables that contain animal ingredients such as fish paste or whey from dairy will be high in histamine. Fermented dairy yogurt may have histamine, cultured meats, and cheese have histamine, and some cultured soy products may have histamine. This is because the high protein ingredients in the foods contain the amino acid histidine that microbes can convert to histamine using the enzyme histidine decarboxylase.
Fermented vegetables made with only vegetables, salt, water, and spices cannot physically contain relevant levels of histamine… this is because the precursor amino acid histidine is not present in relevant amounts in the ingredients, so there’s little to no histidine for microbial enzymes to decarboxylate into histamine. Also, the Lactobacillus spp. in fermented vegetables are able to break down any histamine created with more enzymes.
Microbes in Fermented Vegetables Break Down Histamine
Certain species of Lactobacillus found in fermented vegetables are also capable of breaking down histamine. These species of Lactobacillus can reduce the overall biogenic amine content in all types of fermented vegetables. This is why it is important to ferment your vegetables for a long enough time (21-28 days usually; some vegetables are good at 14 days).
Are any vegetables high in histamine?
Very few vegetables contain relevant levels of histamine, and any relevant levels are usually a result of spoilage microorganisms. (This does not apply to beans, legumes, and starchy vegetables which have varying amino acid content).
People with diagnosed histamine intolerance
Certain types of green leafy vegetables are high in other biogenic amines like putrescine, cadaverine, and tyramine. These biogenic amines are competing substrates for an enzyme called DAO. DAO breaks down histamine in the human body.
Most people who have a histamine intolerance have inadequate DAO, so eating foods with competing substrates is not the best idea. For this reason, people on low histamine diets are told to avoid spinach, kale, eggplant, tomatoes, and avocado.
In general people with histamine intolerance should avoid old, aged, and preserved foods in which the ingredients were high in the amino acid histidine. This includes canned fish, aged meats, cured meats, canned beans, smoked fish, and high protein leftovers.
It should be noted that histamine intolerance can be reversed by reestablishing a healthy gut microbiome.
Obviously, if you have a diagnosed histamine intolerance, follow any recommendations provided by your doctor.
Frias, Juana & Martinez-Villaluenga, Cristina & Peñas, Elena. (2016). Fermented Foods in Health and Disease Prevention.