Thai food is wildly popular around the world, celebrated for its bold flavors, balance of sweet, sour, salty, and spicy elements, and vibrant presentation.
From green curry and pad Thai to tom yum soup and mango sticky rice, Thai cuisine has earned a loyal following far beyond Southeast Asia.
In places like the UK, Thai restaurants and takeaway spots have become staples in many neighborhoods, with diners drawn to the freshness of ingredients and the complexity of the dishes.
But while many enjoy the well-known favorites, few are aware that some traditional dishes carry serious health risks in certain parts of Thailand.
In fact, one beloved Thai delicacy is linked to one of the deadliest cancers in the world—and you probably won’t find it on your local takeaway menu.
Koi Pla, a dish made from chopped raw freshwater fish, herbs, lime juice, and live red ants, is hugely popular in Thailand’s Khon Kaen province. But behind the flavor is a deadly risk: liver cancer.
The raw fish in koi pla often carry fluke worm parasites, which would be destroyed by cooking. But for die-hard fans, cooking the fish “ruins the taste.”
When consumed, these parasites can trigger infections that quietly develop into bile duct cancer over time. Many people who contract the parasite at a young age won’t show symptoms until decades later.
According to the BBC, the dish is thought to cause 20,000 deaths every year in Thailand. The World Health Organisation reports that nearly 70 million people are at risk of infection.
In 2012 alone, nine million people in Thailand, Vietnam, Cambodia, and Laos were known to be infected.
In Thailand’s northeast—one of the country’s poorest regions—koi pla is a staple. The Mekong River, where much of the local fish comes from, is a hotbed for the parasite.
As a result, the area has the highest recorded rates of cholangiocarcinoma (bile duct cancer) in the world. While the cancer makes up just 10% of global cases, it accounts for half of all cancers in northeast Thailand.
Dr. Narong Khuntikeo, who lost both of his parents to liver cancer after they consumed koi pla, is now leading efforts to curb its consumption.
He and a team of researchers have spent years screening residents using ultrasound machines and urine testing kits.
Their findings were alarming: in some communities, up to 80% of people had been exposed to the parasite.
Khuntikeo said it’s been especially difficult to change the habits of older generations. “They’ll say: ‘Oh well, there are many ways to die’,” he noted (via the Guardian). “But I cannot accept this answer.”