Deadly delicious: Thai dishes that should come with a health warning

What is it?

Looking more like a prehistoric fossil than lunch, horseshoe crab turns up in seafood restaurants and markets around southern Thailand. The eggs are the prized part, often scooped from the shell and tossed into a fiery salad with green mango, shallots, chilli and lime.

Why the health warning?

Thailand has different species of horseshoe crab, so telling them apart really matters. The edible plate horseshoe crab can be confused with the smaller mangrove horseshoe crab, which can contain powerful neurotoxins. Poisoning can cause numbness, paralysis and respiratory failure and, in severe cases, death. Cooking doesn’t reliably destroy the toxins either.

This isn’t just a theoretical danger either. Thailand’s Department of Health has issued warnings about confusing the two species following poisoning cases, including a fatal case in Phuket.

Should you try it?

If curiosity gets the better of you, only order it from somewhere reputable that knows exactly what it’s serving. This isn’t the time for a mystery mangrove snack.

Where in Thailand?

Coastal Thailand, including Phuket and the south.

What is it?

You’ll recognise these ridged little shellfish on seafood spreads across southern Thailand, usually quickly blanched so the flesh inside stays soft, juicy and distinctly bloody-looking. They’re commonly dunked into a punchy seafood sauce loaded with chilli, garlic and lime.

Why the health warning?

That barely cooked texture comes with a catch. Blood cockles can harbour Vibrio parahaemolyticus, a bacterium that can cause gastroenteritis. Research specifically examining blood cockles eaten in southern Thailand found that inadequate cooking is the biggest factor increasing the risk of illness.

Thai health authorities advise against eating raw or undercooked shellfish because of the risk of bacterial infection.

Should you try it?

Yes, but ask for your cockles properly cooked rather than barely blanched. You’ll sacrifice a little of that famously soft texture, but your stomach will thank you later.

Where in Thailand

Across Thailand, but particularly at seafood restaurants and markets in the south.

What are they?

Come rainy season, wild mushrooms pop up across Thailand’s forests and foraging becomes part of the annual food calendar. The haul ends up in local markets and kitchens, where mushrooms are thrown into everything from soups to curries.

Why the health warning?

Some poisonous mushrooms look remarkably similar to edible varieties, making a mistake frighteningly easy. Thailand records cases of mushroom poisoning and deaths during the rainy season, particularly in the north and northeast.

And cooking isn’t necessarily the answer. Thailand’s Department of Medical Sciences warns that toxins in some poisonous species are heat resistant and survive boiling, frying and grilling.

Should you try them?

If they’re being served by someone who knows exactly what they are, sure. Heading into the forest and trusting your identification skills after a quick Google search? Absolutely not.

Where in Thailand?

Forested areas across Thailand, particularly the north and northeast during the rainy season.

What are they?

Although most larb is cooked, some traditional versions are made with raw pork, fresh herbs, toasted rice powder, chilli and occasionally pig's blood.

Why the health warning?

Raw or undercooked pork can transmit Streptococcus suis, a bacterium that can cause serious infection. It can lead to sepsis and meningitis and has one particularly alarming complication: hearing loss, which can be permanent. Severe infections can also be fatal.

Should you try them?

When it comes to pork, we say stick with cooked larb. It delivers all the spicy, herby flavour without the health risk.

Where in Thailand?

Northern Thailand and the northeast.

What is it?

Raw freshwater fish is finely chopped and mixed with lime, chilli, herbs and toasted rice powder to make one of Thailand’s most notorious regional dishes. The sharp dressing might make the fish taste as though it has been cooked, but lime juice doesn’t make it safe.

Why the health warning?

Raw or undercooked freshwater fish can carry the Southeast Asian liver fluke Opisthorchis viverrini. Once eaten, the parasites live in the bile ducts, where long-term and repeated infection can cause chronic inflammation. Long-term infection is linked to bile duct cancer, making this one of the most dangerous traditional dishes in Thailand.

Should you try it?

Not on our watch. This is one Thai speciality best left alone. Stick to thoroughly cooked freshwater fish instead.

Where in Thailand?

Northeast Thailand, particularly Isaan and communities around the Mekong basin.

The bottom line

None of this should put you off eating your way around Thailand. The country has one of the world’s great food cultures, and most dishes pose no more risk than lunch anywhere else. But when it comes to raw pork, freshwater fish, foraged mushrooms and some seafood, a little local knowledge goes a long way. Be adventurous – just know when it pays to play it safe.