The Isaan plateau of north-eastern Thailand contains over one third of the population of Thailand. It is not a tourist “hot spot,” the area is economically weak, and much of the terrain is dry. The region is bordered by the Mekong River to the north, by Cambodia to the southeast, and by the Prachinburi mountains south. While the area is poor, it does have one strong thing going for it: a world-renowned cuisine, that specializes in spicy dishes. For example, Thai Papaya Salad originates from the area, as does the fragrant sticky rice. Most dishes, according to a specialist Isaan Food website, are “characterized by fiery chilies, strong fish sauces, sour bites, and flavorful saucy mixtures.”
There is one dish, however, that should be passed on. It is called koi plaa. The dish, Malaya Mail reports, is sourced from small fish caught from rivers and lakes in the area; here after “the pungent dish is made of finely-chopped raw fish, local herbs, lime juice and live red ants, all mixed by hand.”
One thing that has long interested medics surveying this region of Thailand is why abnormally high levels of liver cancer are observed. In men, for instance, this type of cancer accounts for over 50 percent of all cases; however, in almost every part of the world, rates of liver cancer are below 10 percent.
A new investigation has traced the source to infection by liver flukes. These are parasites found in raw fish, and the fish commonly used to create the koi plaa meal have a very high level of flukes. This discovery has been made by Dr. Banchob Sripa at the Tropical Disease Research Laboratory in Khon Kaen University, according to the BBC.
Liver flukes are flatworms that, as their name suggests, infect the liver in many animals. They feed on blood and pass their eggs into the intestines. The eggs pass out through feces and the cycle of infection is repeated. The primary risk in people is that the flukes can trigger cholangiocarcinoma, which is cancer of the bile ducts.
Dr. Banchob Sripa’s research has found liver fluke infection rates in some communities to be has high as 80 percent, with those infected being as young as four years old. Cancer normally develops in those aged 50 and older. Survival rates are low.
The findings have led to a new campaign by authorities in the region for all fish used in dishes to be cooked. This is likely to take some time, given how entangled within the culinary traditions of the area eating raw fish is.
