How to Get Rid of Parasites from Sushi

Digestive health · Part 1 of the parasite series

By Brehan Crawford, L.Ac., MAcOM · Licensed acupuncturist, Crawford Wellness · Updated October 2026

Yes, you can get worms from raw fish. And yes, traditional Japanese cuisine already figured out the botanical answer, centuries before anyone called it a parasite cleanse. Here is what the research says about shiso, ginger and wasabi, and when you should skip the plants and see a physician.

The video that started this series.

Let me be direct with you, the same way I am in every video: I have spent years debunking the online parasite-cleansing industry. The glitter-bomb laxatives, the 30-day rope-worm protocols, the influencer kits promising to purge everything mysterious from your gut. None of that is grounded in solid evidence, and plenty of it is actually harmful.

But here is the thing. While the internet is selling you $89 parasite cleanse bundles, traditional Japanese cuisine has quietly been deploying real, research-backed antimicrobial and antiparasitic plant medicine on every sushi platter for centuries. I am talking about shiso leaf, ginger and wasabi, the trio of botanicals most Western diners either ignore or trade for the plastic decorative version.

This post is my love letter to traditional food wisdom and a gentle public service announcement for anyone eating raw fish without these plants on the side. It is also a reminder that herbal medicine is sophisticated, not trendy. Real parasite protection does not come in a 30-capsule kit sold by a wellness influencer.

“Traditional Japanese sushi accompaniments are not garnishes. They are a complete botanical defense system developed across centuries of empirical medicine.”

— Brehan Crawford, L.Ac., MAcOM

First, let's talk about Anisakis

Anisakis is a genus of parasitic roundworms whose life cycle runs through fish and marine mammals. When you eat raw or undercooked fish, including salmon, mackerel, herring, squid and anchovies, you can ingest third-stage larvae that are perfectly capable of embedding in your gastrointestinal tract. The resulting condition, anisakiasis, can cause severe abdominal pain, nausea and vomiting within hours, and occasionally requires endoscopic or surgical removal.

This is not a fringe risk. A 2020 systematic review found Anisakis larvae in fish sourced globally, with rising incidence tracking the international popularity of raw fish cuisine. The FDA's primary recommendation is freezing fish before serving it raw, and reputable sushi establishments follow that protocol. But what if your raw fish experience goes beyond restaurant dining? Fishing, preparing your own sashimi, or eating somewhere without strict cold-chain protocols? That is where traditional botanical food medicine enters the picture, and where the science gets genuinely interesting.

The three botanical allies on your sushi plate

1. Shiso (perilla leaf), the antimicrobial shield

In Japan the leaf beside your sashimi is shiso, Perilla frutescens. In Chinese medicine we call it zi su ye, and it has been used for millennia as a digestive herb, a seafood-safety companion, and an antidote to what classical texts describe as fish and crab toxicity. The ancient Chinese already knew you pair perilla with raw seafood. Now we know why.

Perilla essential oil shows significant antibacterial activity in laboratory research against Staphylococcus aureus, one of the most common and dangerous foodborne pathogens. It appears to work by disrupting bacterial cell membrane integrity, permeabilising the membrane in a time- and concentration-dependent manner, causing leakage of intracellular contents and cell death. Because it targets the membrane rather than a specific enzymatic pathway, it stays effective against antibiotic-resistant strains. Similar activity has been confirmed against Salmonella and E. coli.

Beyond antibacterial action, perilla is rich in rosmarinic acid, flavonoids and omega-3 fatty acids. In Chinese medicine it is pungent and warm: it moves qi, resolves dampness and calms the Stomach. Clinically I use it for nausea, bloating and unsettled digestion after a rich or unfamiliar meal, which describes a lot of sushi experiences.

2. Ginger, the digestive powerhouse with real antiparasitic activity

If I had to pick one plant I have prescribed more than any other, it would be ginger (Zingiber officinale). It is a warming carminative, a prokinetic, an anti-nausea agent and an anti-inflammatory. In Chinese medicine it tonifies the middle, warms the Stomach and Spleen, and disperses cold. It is one of the most remarkable digestive aids there is, and I do not say that lightly.

Ginger's antiparasitic properties are what I want to highlight. Multiple studies show genuine anthelmintic activity. In animal studies ginger has acted against a wide range of gastrointestinal nematodes, including Strongyloides ransomi, Hyostrongylus rubidus, Trichostrongylus axei and Globocephalus urosubulatus. The active compounds appear to include gingerol, shogaol and related phenolics, which act on worm neuromuscular function, likely through cholinergic pathways, causing paralysis and death of the parasite. Research has also documented activity against Anisakis simplex specifically, the very worm most relevant to raw fish. Traditional Japanese food medicine paired pickled ginger with raw fish for good reason, and the reason turns out to be molecularly verifiable.

I want to be precise: the anthelmintic doses demonstrated in research are higher than what you eat with sushi. The pickled ginger on your plate is a beginning, not a clinical intervention. But in a whole-meal context, alongside the other plants here, you are creating a genuinely hostile environment for opportunistic parasites. That is the ecology-over-warfare approach that defines how I think about botanical medicine.

3. Wasabi and horseradish, the compound that kills Anisakis

Real wasabi (Wasabia japonica) is expensive and rare outside Japan. What you get at most restaurants is green-tinted horseradish, but both plants deliver the same bioactive compound: allyl isothiocyanate, or AITC. AITC is what makes them fiery, sinus-clearing and, crucially, nematocidal.

Research in the Journal of Helminthology investigated the nematocidal effects of wasabi paste and isolated AITC on third-stage larvae of Anisakis pegreffii, the parasite directly implicated in anisakiasis from raw seafood. Wasabi paste at standard concentrations significantly reduced larval viability, with mean lethal times of 30 to 45 minutes depending on concentration. Pure AITC was even more potent, producing 50% larval mortality in 16 minutes. The mechanism involves disruption of the parasite's heat shock protein pathways, its internal damage-control system. The researchers concluded that wasabi-derived compounds show genuine promise for reducing the risk of anisakiasis from raw seafood.

Again, honesty: a thin smear of wasabi on nigiri is not a pharmaceutical dose. The research used concentrated preparations. But combine AITC from wasabi with ginger's anthelmintic gingerols and shiso's membrane-disrupting compounds, in a meal that creates a systemically inhospitable environment for parasites, and you have cumulative botanical action. This is how traditional food medicine works.

“Ecology over warfare. You are not trying to obliterate every organism in your gut. You are creating conditions where pathogens cannot thrive. That is what traditional food medicine does.”

— Brehan Crawford, L.Ac., MAcOM

Why I keep debunking online parasite cleanses

I am not anti-herbal medicine. I am a practitioner of herbal medicine. What I am against is the unregulated, misrepresented, fear-based parasite cleanse industry that has taken genuine botanical science and turned it into glamorised laxatives.

Most online parasite cleanses are built around black walnut hull, cloves and wormwood, which do have real antiparasitic properties in a clinical context. The problem is dosing, sourcing, formulation, duration and indication. At the doses sold in typical online kits these herbs are unlikely to reach therapeutic antiparasitic concentrations. At higher doses some are genuinely toxic. And the rope worms and biofilm ropes people photograph after these cleanses? That is intestinal mucus and undigested fibre. It is not a parasite.

If you suspect a real parasitic infection, meaning actual clinical symptoms, exposure through travel or raw food, or something that showed up on stool testing, work with a qualified provider. A physician can test for parasites and, if confirmed, prescribe antiparasitic medication that works reliably and quickly. If those medications do not work, or you have side effects, that is when clinical herbal medicine becomes valuable, and that is exactly the work I do.

The plants in your sushi are not a cleanse. They are daily, cumulative, intelligent botanical protection, tested not in clinical trials but in the long, slow laboratory of human civilisation. I take the cleanse industry apart ingredient by ingredient in Part 2 of this series: The Parasite Cleanse Industry is a Scam.

When to actually see a physician

I said it in the video and I will say it again: if you genuinely think you have a parasitic infection, if this post reached you after the sashimi rather than before, see a physician. Antiparasitic medications are effective. Albendazole, mebendazole and ivermectin work reliably for most common worm infections, and you should take them if your provider confirms you need them.

If the drugs do not fully work. If you have ongoing gastrointestinal symptoms after treatment. If you have side effects that affect your quality of life. If you live with chronic gut dysfunction that conventional gastroenterology has not resolved. That is where clinical herbal medicine excels, and where I would love to support you.

Questions people ask

Does freezing fish really kill parasites?

Yes. The FDA specifies freezing times and temperatures that kill Anisakis larvae, and reputable sushi restaurants follow them. Home-caught or home-prepared raw fish is where the risk rises.

Will eating ginger and wasabi with sushi protect me?

They lower the odds; they do not eliminate the risk. Treat them as daily, cumulative protection, not a treatment.

I ate sushi and now have stomach pain. What do I do?

See a physician, especially if the pain is severe or started within hours. Anisakiasis is diagnosable and treatable, and sometimes the larva needs to be removed endoscopically.

Keep reading

References and further reading

1. He W, et al. (2020). Antimicrobial activity and mechanism of action of perilla essential oil against Staphylococcus aureus. E3S Web of Conferences, 145, 01015. Read paper
2. Kiambom T, et al. (2021). In vivo anthelmintic effect of ginger (Zingiber officinale) powder against gastrointestinal nematodes of artificially infected pigs. Archives of Veterinary Science and Medicine, 4(1), 1–12. Read paper
3. Rahmati AR, et al. (2020). Nematocidal activity of wasabi paste and allyl isothiocyanate against Anisakis third-stage larvae and their stress response characterised by heat shock protein expression. Journal of Helminthology. Read abstract
4. Iqbal Z, et al. (2006). In vivo anthelmintic activity of ginger against gastrointestinal nematodes of sheep. Journal of Ethnopharmacology, 106, 285–287. PubMed
5. Lin RJ, et al. (2014). Anthelmintic constituents from ginger (Zingiber officinale) against Hymenolepis nana. Acta Tropica, 140, 36–45. PubMed
6. Rahmati AR, et al. (2020). World-wide prevalence of Anisakis larvae in fish and its relationship to human allergic anisakiasis: a systematic review. Parasitology Research, 119, 3585–3594.

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