Avoid the walu (or escolar or butterfish or ex-lax fish or whatever it is called)…
Back in the early 1990s, I recall reading an article about a new fish on the culinary scene called escolar. It was all the rage in trendy restaurants at time. Delicious. Chefs loved to prepare it because its high fat content made it easy to cook with a crisp exterior and delicate flaky interior.
There was was only one slight problem with this otherwise delectable fish, a good percentage of people who enjoyed it would end up with diarrhea that night (technically, it is a steatorrhea which is very loose stools due to the malabsorption of fat). The more fish you ate, the more likely you would get the runs.
The sale of escolar has been banned in Italy and Japan (really, Japan! They still allow the sale of potentially fatal sushi from pufferfish). The FDA considered banning escolar in 1990′s, but now just informally recommends, “Escolar should not be marketed in interstate commerce.” Whatever that means…
So those many years ago, as an adventurous younger man, the first opportunity I had to try escolar, I went for it. And yes, I was a witting victim of its untoward effects. I have seen it on fine menus and in upscale markets often ever since (and avoided it).
Now twenty some years later, here I am on the first night of vacation in Hawaii, desperately seeking some good fresh seafood. Out to fine restaurant, fresh catch is walu. “Walu?” I ask. I am told that walu is also known as butterfish. It is to be prepared grilled over fresh steam vegetables. Just the ticket.
Well, you could guess where this story went from there. Walu is the local name for escolar. This time, I was an unwitting victim and spend most of our first night…
This is a somewhat cautionary tale too. Escolar often sneaks into the fish market as “super white tuna”, “king tuna”, “butterfish” or “ono”, though it is none of those (en.wikipedia.org/wiki/Escolar). A healthy individual could enjoy the delicious taste of escolar and probably if eaten in small enough quantities not suffer much beyond a loose bowel movement. However, I am not sure of the wisdom of serving a very powerful (and uncomfortable) laxative to people in frail health or with pre-existing gastrointestinal disorders. Probably not a good choice for weight management either.
Aloha,
Dr Jeff
Image source: ”Regulatory Fish Encyclopedia: U.S. Food and Drug Administration, 1993-2013″