Is tomato high in histamine?
Tomato is moderate in histamine: tested tomatoes averaged 2.51 mg/kg with some up to 17 mg/kg, far less than spinach, yet 9 of 10 published low-histamine diets exclude it.
- Histamine
- Varies by sample
- Other amines
- Notable levels
- Liberator
- Claimed, unproven
- DAO blocker
- No evidence
Why sources disagree. Nine of ten published diets exclude tomato, but measured histamine is low on average (2.51 mg/kg). The concern rests on occasional higher samples, putrescine and an unproven "liberator" claim.
What each source says
| Source | Verdict | What it says, in our words |
|---|---|---|
| Lab measurements, Spain 1 | Measured | Average 2.51 mg/kg in 53 fresh tomatoes; highest 17.07 mg/kg. |
| 10 published low-histamine diets 1 | 9 of 10 exclude tomato. | |
| Histamine-liberator claim 1 | Listed among suggested histamine-releasing foods; no human study supports the claim. | |
| SIGHI food list 3 | See source | See SIGHI's own list for its rating. |
Measured histamine
| Food tested | Samples | Histamine | Other amines |
|---|---|---|---|
| Fresh tomatoes sold in Spain 1 (Table 1) | 53 | mean 2.51 mg/kg, range nd–17.07 mg/kg, 95th percentile 13.83 mg/kg | putrescine mean 16.48 mg/kg (6.29–35.55) |
| Crushed tomato 2 (Table 1) | 3 | mean 1.22 mg/kg, range 0.24–3.17 mg/kg | putrescine mean 9.66 mg/kg |
| Ketchup 2 (Table 1) | 3 | mean 0.37 mg/kg, range nd–1.11 mg/kg | putrescine mean 1.07 mg/kg |
| Range reported by other studies 2 (Table 4) | — | range nd–17 mg/kg | putrescine 5–122 mg/kg |
mg/kg = milligrams of histamine per kilogram of food. "Not detected" means below the laboratory's detection limit.
How freshness and processing change it
As with spinach and eggplant, the 2021 review links higher histamine in tomato to bacterial activity during storage. Tomato sauce kept and reheated over several days is a bigger load than a freshly made one, because histamine survives cooking and builds up as food is stored.
Average 2.51 mg/kg, up to 17.07 mg/kg. (measured)
Average 1.22 mg/kg, but only 3 samples were tested. (measured)
Average 0.37 mg/kg in 3 samples; too few samples to rate lower. (measured)
Putrescine averaged 25.9 mg/kg; histamine was not reported. (estimate)
Not measured. Storage time adds histamine, and reheating does not remove it. (estimate)
Why we rate tomato 2
Tomato is excluded by nine of the ten published low-histamine diets reviewed in 2021, more than any other plant food. The measurements are less dramatic. A University of Barcelona team tested 53 fresh tomatoes sold in Spain and found an average of 2.51 mg/kg of histamine. Some samples had none, the highest had 17.07 mg/kg, and 95% were below 13.83 mg/kg. That is far below eggplant (39.42 mg/kg on average) or spinach (31.77 mg/kg), two vegetables that fewer lists exclude.
So why the near-unanimous exclusion? Three reasons appear in the literature. First, tomato does contain some histamine, and the higher samples matter for people who are sensitive. Second, tomato carries putrescine, averaging 16.48 mg/kg in fresh tomato and up to 122 mg/kg in other studies. Putrescine may compete with histamine for the DAO enzyme, but the evidence for that comes from old animal and laboratory work. Third, tomato is often called a "histamine liberator", a claim with no supporting studies in humans.
Processed tomato is not automatically worse. Three samples of crushed tomato averaged 1.22 mg/kg and three of ketchup 0.37 mg/kg, although three samples are too few to rely on. Tomato concentrate had more putrescine, 25.9 mg/kg on average, and its histamine was not reported.
We rate tomato 2, "moderate", and mark it disputed. Histamine turns up regularly in tomato, but at low levels, so it sits below the "avoid" that nine of ten lists imply. For many people a few slices of fresh tomato will be fine; a large bowl of long-simmered or leftover sauce is a bigger load. If you are avoiding tomato, sauces based on roasted pumpkin or carrot are the usual swap, and grated courgette (zucchini) adds moisture to a sauce. Make tomato sauce fresh rather than reheating it over several days, because histamine survives cooking and builds up as food is stored.
Questions about tomato and histamine
Is ketchup high in histamine?
Three samples of ketchup in a 2018 study averaged 0.37 mg/kg of histamine, which is low, but three samples are too few to rely on. We rate it 2, the same as tomato, until there is more data.
Are cooked tomatoes lower in histamine than raw?
Not the way tomatoes are usually cooked. Histamine is heat-stable; boiling vegetables in water that is then poured away can lower it, but a tomato sauce keeps its liquid, and sauce that is stored and reheated has more time to build it up.
Evidence behind this page
- Fresh tomatoes sold in Spain averaged 2.51 mg/kg of histamine (53 samples, maximum 17.07 mg/kg). 12
- Nine of ten published low-histamine diets exclude tomato. 1
- Tomato concentrate averaged 25.9 mg/kg of putrescine; other studies report up to 122 mg/kg in tomato. 2
- The idea that foods such as tomato release the body's own histamine has no supporting human studies. 1
Sources
- 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)
- 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)
- 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)