How we rate foods for histamine
Every food gets a rating from 0 to 3. The rating is ours; the sources behind it are on each food's page, including the ones that disagree with us.
- generally well tolerated
- fine for many people
- small portions, watch freshness
- usually avoided on a low-histamine diet
The rule
- Measured histamine first. Where a laboratory study reports histamine for the food, we start there.
- Not detected in any or almost any sample, with low levels of other amines: 0.
- Not detected in most samples, but found in some: 1.
- Detected regularly, at an average up to about 20 mg/kg: 2.
- Average above about 20 mg/kg, or 5% of samples above about 50 mg/kg: 3.
- Foods with a known way to build up histamine fast (histidine-rich fish such as tuna, and fermented foods) and documented samples above 100 mg/kg: 3, even when the average is low, because you cannot tell a high sample from a low one by looking at it.
- One step for other amines or wide exclusion, never more. A notable level of putrescine, cadaverine or tyramine (a measured average of 10 mg/kg or more), or exclusion by 6 or more of the 10 published diets below, moves a 0 to a 1. The evidence that other amines block histamine breakdown is limited to old animal and laboratory studies, and there are no human studies showing that any food releases the body's own histamine (the "liberator" idea), so neither can make a food moderate or high on its own.
- The published diets are shown, not followed. We use the count from a 2021 review of ten published low-histamine diets (Sánchez-Pérez and colleagues, Nutrients). It appears on every page as "N of 10 published diets exclude this food". Beyond the one step above, we do not change a rating to match the lists. When our rating and the lists point in different directions, the food is marked disputed and the page explains why.
- Freshness and processing are rated separately. Histamine forms during storage and is not destroyed by cooking, canning or reheating, although boiling vegetables can move some of it into the cooking water. The main rating is for the fresh food as usually bought. Leftovers, canned, smoked, ready-cooked and deli forms get their own line on the page, marked "measured" or "estimate".
- Foods without measurements are rated from how they are made and stored (fermented, aged, histidine-rich fish, stored protein) and are labelled "not measured". Where we only have figures for a food group, such as "fresh white fish", the page says "measured as a food group".
What we use, and what we do not
Our measurements come from peer-reviewed studies, mainly the University of Barcelona team's surveys of foods sold in Spain, which are the largest published set for this purpose. Retail foods elsewhere may differ. We cite the table or figure for every number.
We link to the Swiss Interest Group Histamine Intolerance (SIGHI) list because many readers use it, but we do not reproduce its ratings. SIGHI's list is their copyrighted work, and our ratings are built independently from the studies.
Every food page needs at least two distinct citations and at least 250 words written for that food; pages that fail either check do not build. A page is open to search engines before a dietitian has reviewed it only if the food itself was measured in a cited study, and it says so at the top; other pages stay hidden from search engines until reviewed. See the editorial policy.
What a rating is not
A rating is a summary of published evidence about a food, not a prediction of how you will react. Tolerance varies a lot between people, and histamine intolerance is diagnosed by excluding other conditions, so symptoms are worth taking to a doctor. Low-histamine diets are usually done for a limited time with a dietitian, followed by reintroducing foods one at a time. See our medical disclaimer.