Houttuynia Cordata (Fish Mint): Flavor, Chemotypes, Uses and Safety

Crush a leaf of Houttuynia cordata and you’ll see where the name fish mint comes from: it smells strongly of fish. It isn’t a mint at all (it’s in the family Saururaceae), and depending on the plant, the smell can also lean toward coriander leaf or a strange lemon-orange note. This low, creeping East Asian herb is eaten raw in salads and as a garnish across East and Southeast Asia and northeast India, and in some places the rhizome goes into the pot too.

At a glance

What it is

Houttuynia cordata is a rhizomatous geophyte of the temperate biome, native from the Himalaya to temperate East Asia and Indo-China. It grows wild in semi-shaded marshy places and is occasionally cultivated, particularly in Thailand and Indo-China. It’s also often grown as an ornamental in Europe and the United States.

The genus is named for Maarten Houttuyn (1720 to 1798), a Dutch naturalist. Kew dates the species name, authored by Thunberg, to 1783.

The names tell you about the smell. Katzer translates the Chinese yuxing cao as “fish-stinking herb” and reads the Vietnamese diếp cá as lettuce that smells like fish. He says the English names fishwort and heartleaf refer, with some exaggeration, to the odor and to the heart-shaped leaves.¹

Flavor and aroma

Fishy is the word everyone reaches for, but it’s not the whole story, and it depends on which plant you’ve got. Katzer describes two chemotypes, chemically distinct forms of the same species:¹

Katzer finds the taste aromatic and very close to Vietnamese coriander, with an astringent aftertaste. Some people compare the smell to raw fish or meat, he says, but he doesn’t.¹ PROSEA, on the other hand, plainly describes the crushed leaves as having a fish-like, fetid odor.³ Both are fair. The fishiness is real, but it varies by plant and by palate.

The compound behind the fish

Katzer names decanoyl acetaldehyde as the compound mainly responsible for the characteristic flavor, and Wu and colleagues’ 2021 review says houttuynin, the same compound, has “a special fishy scent.”¹² The review lists nonyl ketones among the main components of the essential oil, at 2.10% to 40.36% across the samples it cites. That range is so wide that no single figure is typical.²

How it is used

• Vietnam. The leaves sometimes turn up in Vietnamese salads and garnishes.
• Northeast India. In Manipur, cooks use both the leaves and the fresh rhizome. Katzer describes the leaves in salads like singju, in the fermented-fish dish iromba, where the herb cuts the intense fermented fish flavor, and dipped in chickpea-flour batter for bora, a fritter.¹ Wu and colleagues note it’s harvested as daily food and medicine in the Yarlung Zangbo valley of Assam.²
• Southwest China. Katzer describes a Guizhou dish of salt-cured bacon fried with the rhizome.
• Nepal. It’s little used, though some people flavor pickles with the fresh leaves or rhizomes.
• General. The leaves are eaten raw, in salads or as a garnish for several dishes.

Its use has been described in China, Korea, Japan, India and other Asian regions.

It’s at its best raw and in small amounts, torn into herb plates, rice-paper rolls and salads where coriander or other strong herbs balance it. New to it? Try a few leaves alongside cilantro before you build a dish around it.

Buying and storage

We didn’t find a grading standard or published shelf life. Buy bright, unwilted leaves, refrigerate them wrapped in a damp towel, and use them within a few days, as you would any tender leaf herb.

Health and safety

As food. Wu and colleagues found no reports of toxicity from long-term eating of the plant as a vegetable, and call it relatively safe for oral use in humans.²

Compounds. The same review lists rutin, hyperoside, quercetin and quercitrin among its flavonoids and calls flavonoids and volatile oils its main active components. Most of the research on what these compounds do comes from cell and animal studies. The review itself says some of its findings were “mainly investigated in vitro” and need confirming in living systems.² None of this shows that eating the herb treats or prevents any disease.

Traditional medicine. In China, the aboveground parts are used in traditional medicine for pneumonia and lung abscess.² That records a tradition. It isn’t evidence that it works.

Injections are a separate matter. In China, the herb has also been made into an injectable drug. A 2010 systematic review collected 1,232 reported adverse reactions to Houttuynia injection from 645 articles. Anaphylactic shock made up about 59% of the most serious reactions, and the authors concluded that the reactions “were serious.”⁴ That’s about an injected drug, not the leaf eaten as food.

Open questions. In its safety discussion, the 2021 review also cites studies associating aristolochic acid and aristolactams with liver cancer, and a high-dose 28-day rat study in which some animals died and kidney cells showed focal necrosis.² Those are animal and literature findings, not evidence of harm from culinary amounts.

Substitutes and comparisons

Nothing reproduces the fishy note. For the green, coriander-like side of the flavor, cilantro or culantro can stand in. Shiso is another strong leaf for herb plates. For herbs that really are in the mint family, see types of mint and Korean mint.

Ratio (Method): Use more cilantro or culantro than you would fish mint, and treat that as a starting direction.