Is onion high in histamine?
Onion is low in histamine: four onions tested in Spain had no histamine and no other biogenic amines at all. Other studies found low putrescine, and one found cadaverine in a test of two onions.
- Histamine
- Not detected
- Other amines
- Low
- Liberator
- Not on the lists we use
- DAO blocker
- No evidence
What each source says
| Source | Verdict | What it says, in our words |
|---|---|---|
| Lab measurements, Spain 1 | Measured | No histamine, tyramine, putrescine or cadaverine in 4 onions. |
| Other studies in the 2018 review 1 | Putrescine 0.5–7.2 mg/kg and tyramine up to 3 mg/kg; one study of 2 samples found cadaverine at 29.32 mg/kg. No histamine reported. | |
| 10 published low-histamine diets 2 | Onion is not on the review's chart of foods the diets exclude. | |
| SIGHI food list 3 | See source | See SIGHI's own list for its rating. |
Measured histamine
| Food tested | Samples | Histamine | Other amines |
|---|---|---|---|
| Onions sold in Spain 1 (Table 1) | 4 | not detected | tyramine, putrescine and cadaverine not detected |
mg/kg = milligrams of histamine per kilogram of food. "Not detected" means below the laboratory's detection limit.
How freshness and processing change it
Onions keep well, and none of the studies we use reports histamine forming in them during storage. Pickled onions, onion powder and ready-fried onions were not measured.
No amines in 4 raw onions; cooking does not create histamine. (measured)
Why we rate onion 0
Onion came out with the cleanest result of any vegetable in the University of Barcelona team's Spanish survey. Four onions were tested, and none contained histamine, tyramine, putrescine or cadaverine. Putrescine, which the team found in every other vegetable and legume in their own database, was not detected in their onions at all.
Four samples is a small number, so the other studies the team's 2018 review collected matter here. None of them reported histamine in onion. They did find some putrescine, at levels from 0.5 to 7.2 mg/kg, all low, and one reported tyramine at 3 mg/kg. One study, by Nishimura and colleagues, reported cadaverine at 29.32 mg/kg, but it tested only two samples, and the review singles it out as an exception: across the vegetables it covered, average cadaverine otherwise never exceeded 8 mg/kg. We rate from the larger, more complete measurement.
Onion does not appear among the foods charted as excluded by the ten published low-histamine diets in the team's 2021 review. Because that chart covers only some foods, we do not claim that every diet allows onion; we found none in our sources that excludes it.
That makes onion one of the most useful ingredients on a low-histamine diet, because so many savoury dishes start with it. Frying, roasting or caramelising onion does not create histamine, and raw onion had none to begin with. What the studies did not cover are the processed forms: pickled onions, onion powder and ready-fried onions were not measured, so they are not rated by these figures.
We rate onion 0, "low". Some people find onions hard to digest for reasons that have nothing to do with histamine; if onion gives you symptoms, that is worth raising with your dietitian rather than assuming histamine is the cause.
Questions about onion and histamine
Is garlic low in histamine too?
Garlic was not measured in the studies we use, and onion's result does not carry over to it. We estimate fresh garlic low from how it is grown and stored; the garlic page explains the estimate.
Are spring onions and shallots low in histamine?
They were not measured separately. The studies we use tested common bulb onions only.
Evidence behind this page
- Four onions sold in Spain had no detectable histamine, tyramine, putrescine or cadaverine. 1
- Other studies reported putrescine in onion from 0.5 to 7.2 mg/kg and tyramine at 3 mg/kg; one study of two samples reported cadaverine at 29.32 mg/kg, which the review describes as an exception. 1
- Onion does not appear among the foods charted as excluded by ten published low-histamine diets. 2
Sources
- Sánchez-Pérez S, Comas-Basté O, Rabell-González J, Veciana-Nogués MT, Latorre-Moratalla ML, Vidal-Carou MC. Biogenic Amines in Plant-Origin Foods: Are They Frequently Underestimated in Low-Histamine Diets? Foods 7(12):205, 2018. doi:10.3390/foods7120205 (Sánchez-Pérez S et al. 2018)
- Sánchez-Pérez S, Comas-Basté O, Veciana-Nogués MT, Latorre-Moratalla ML, Vidal-Carou MC. Low-Histamine Diets: Is the Exclusion of Foods Justified by Their Histamine Content? Nutrients 13(5):1395, 2021. doi:10.3390/nu13051395 (Sánchez-Pérez S et al. 2021)
- Swiss Interest Group Histamine Intolerance (SIGHI). Food compatibility list for histamine intolerance. histaminintoleranz.ch (accessed November 2026), 2026. Link (Swiss Interest Group Histamine Intolerance (SIGHI) 2026)