Which fish is associated with digestive issues when eaten in large amounts?

• A. Salmon
• B. Tuna
• C. Escolar
• D. Cod

Answer: (C)

Digestive upset from certain fish is linked to wax esters that resist digestion. Escolar contains unusually high levels of these wax esters, which are not well absorbed by the human gut. When you eat larger portions, these waxes pull water into the intestines and can slow digestion, leading to diarrhea, abdominal cramps, nausea, or oily stools. It isn’t that the fish is toxic, but the wax esters act like a strong laxative in the digestive tract. Because of this effect, many guidelines recommend keeping portions small or avoiding large servings of escolar. In markets it’s sometimes labeled as “butterfish” or even “white tuna,” which can be confusing, but the symptom pattern comes from these wax esters. Other commonly eaten fish such as salmon, tuna, and cod don’t carry this same issue and are typically consumed without the specific digestive distress associated with escolar, though standard considerations like allergies or contaminants still apply.