Is Escolar a Good Fish to Eat? The Buttery Flavor with a Risky Side Effect

While prized for its rich, buttery taste, eating escolar can cause severe, oily diarrhea known as keriorrhea in a significant portion of the population. This startling side effect is caused by indigestible wax esters stored in the fish's flesh, presenting a major dilemma for seafood lovers.

Quick Summary

Escolar is an oilfish prized for its buttery taste but notorious for causing digestive distress due to indigestible wax esters, a condition called keriorrhea.

Key Points

• Rich Flavor, Risky Payoff: Escolar is prized for its buttery flavor and smooth texture, but contains indigestible wax esters that can cause digestive issues.

• Keriorrhea is the Risk: The primary side effect is keriorrhea, an oily, yellow-orange diarrhea that is a physiological reaction, not bacterial food poisoning.

• Moderation is Key: To reduce risk, limit consumption to 6 ounces or less, especially for first-time eaters.

• Often Misidentified: Escolar is frequently mislabeled as "white tuna," "super white tuna," or "butterfish" in restaurants.

• Cooking Doesn't Eliminate the Risk: Cooking methods like grilling do not reliably remove the indigestible oils from the fish.

• Regulated in Some Regions: Some countries, like Japan and Italy, have banned the sale of escolar due to its side effects.

• Avoid If Vulnerable: Pregnant women, the elderly, and individuals with bowel issues should avoid escolar entirely.

The Alluring Flavor and Dangerous Secret of Escolar

Escolar, sometimes sold deceptively as "white tuna" or "super white tuna," has earned a reputation as a high-risk, high-reward delicacy. The fish's appeal lies in its succulent, buttery flavor and firm, silky texture, which is rich due to its high fat content. However, this very richness is also its major downfall. Escolar cannot metabolize the wax esters found in its diet, storing them in its flesh, which humans cannot digest either. These indigestible wax esters, also known as gempylotoxin, are the culprit behind the unpleasant digestive side effects associated with consuming this fish.

The Health Risks of Eating Escolar: Keriorrhea Explained

The most significant health risk of eating escolar is the gastrointestinal condition known as keriorrhea, from the Greek meaning "flow of wax".

What is Keriorrhea?

Keriorrhea is the involuntary and sometimes sudden expulsion of oily, orange or yellow liquid from the rectum, often described as a greasy diarrhea. It is not a form of food poisoning from bacteria, but a physiological reaction to the indigestible wax esters passing through the digestive tract. While unpleasant, it is typically not life-threatening and does not cause significant fluid loss.

Symptoms and Onset Time

Symptoms of keriorrhea can include:

• An oily, orange or yellow discharge
• Severe diarrhea
• Abdominal cramps
• Nausea and vomiting
• Headaches

The onset of these symptoms can range from 1 to 90 hours after eating, with a median of 2.5 hours. The duration of symptoms usually lasts one to two days. The severity is dose-dependent, meaning a larger portion increases the likelihood and intensity of symptoms.

Who is at Risk?

While susceptibility varies among individuals, nearly half to two-thirds of people may become ill after consuming escolar. Certain groups are advised to be particularly cautious or avoid it altogether, including:

• Pregnant women
• Individuals with bowel problems or malabsorption issues
• The elderly and young children

Escolar vs. True White Tuna

One of the main reasons for accidental escolar consumption is widespread mislabeling in the seafood industry, particularly in sushi restaurants. Escolar is a cheaper alternative to fatty tuna and is often sold as "white tuna," misleading consumers.

The Mislabeling Problem

The practice of selling escolar under false names like "white tuna," "butterfish," or "walu" is ethically problematic because it withholds vital information about the potential side effects. Studies have found significant levels of mislabeling in restaurants, highlighting the importance of purchasing seafood from reputable sources and asking explicit questions about the fish species being served.

Comparison Table: Escolar vs. True White Tuna (Albacore)

Feature	Escolar	Albacore (True White Tuna)
Family	Snake Mackerel (Gempylidae)	Tuna (Scombridae)
Wax Esters	High concentration, indigestible	None
Primary Risk	Keriorrhea (oily diarrhea)	Mercury (in large quantities)
Flavor	Buttery, rich, and clean	Mild, less oily than Escolar
Texture	Silky, fatty	Firm, steak-like
Cost	Generally less expensive	Higher price point
Mislabeling	Often sold as "white tuna"	The only fish legally permitted to be sold as "white tuna" in the US

Safe Consumption and Global Regulations

Despite the risks, some people still choose to enjoy escolar in moderation. If you decide to try it, following a few precautions is essential:

1. Limit Portion Size: The most commonly recommended serving size is 6 ounces or less. First-time consumers should start with an even smaller portion, around 3-4 ounces, to gauge their individual sensitivity.
2. Purchase from Reputable Sources: Buy escolar from trusted vendors that provide transparent and accurate labeling. This helps ensure you know exactly what you are eating and can make an informed choice.
3. Choose Cooking Methods Wisely: While cooking doesn't eliminate the wax esters, some suggest methods that allow the oil to drain, such as grilling. However, the effectiveness of this approach is disputed, and limiting the portion size remains the most reliable strategy. Discarding the cooking liquid is also recommended.

International Bans and Warnings

Some countries have taken a more stringent stance on escolar. Japan banned its sale in 1977, and Italy has also forbidden its commercialization. In Canada and Australia, health authorities issue explicit warnings about the risks and recommend strict labeling standards. The U.S. FDA, after a brief import ban in the 1990s, now advises against its interstate marketing, but it is not technically banned.

Conclusion: A Delicacy with a Clear Warning

Is escolar a good fish to eat? The answer is nuanced. From a culinary perspective, its rich flavor and decadent texture make it a high-end experience. However, the significant risk of keriorrhea means it is not a "good" fish for everyone, especially those with sensitive digestive systems. Ultimately, responsible consumption requires awareness, honesty from sellers, and strict moderation from diners. Always be informed about what you are eating, particularly when ordering "white tuna" in a restaurant. For more information on seafood handling and safety, the NOAA FishWatch website is a valuable resource.

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Comparison of Safety Precautions

Method	Effectiveness	Details
Limit Portion Size	High	Most reliable method; 6 oz or less recommended.
Grill or Broil	Low to Moderate	May help drain some oil but does not eliminate risk; cook-off oil is not a substitute for moderation.
Buy from Reputable Source	High	Reduces risk of accidental consumption due to mislabeling.
Avoid if Pregnant	High	Precautionary avoidance recommended for vulnerable groups.
Freeze Fish	None	Freezing does not break down the wax esters.

Final Thoughts: Should you eat escolar?

It is ultimately a personal decision. If you have no underlying health conditions and are willing to accept the risk of digestive issues, start with a very small portion to see how your body reacts. If not, there are plenty of other delicious fish to enjoy without the risk of an oily, embarrassing side effect.

Frequently Asked Questions

What is keriorrhea?

Keriorrhea is the production of an oily, orange or yellow discharge from the rectum caused by the human body's inability to digest the wax esters found in escolar and oilfish.

Is keriorrhea from escolar a serious health risk?

While uncomfortable and embarrassing, keriorrhea from escolar is generally not considered life-threatening and usually resolves within one to two days without medical intervention.

Does cooking escolar fish make it safe?

No, cooking does not break down the indigestible wax esters in escolar fish. Methods like grilling might drain some oil, but the main risk factor remains.

Why is escolar often mislabeled as white tuna?

Escolar is sometimes sold as "white tuna" because it is a cheaper alternative to real tuna and has a fatty, desirable texture similar to tuna belly. This practice is deceptive and prevents customers from knowing the associated risks.

Which countries have banned escolar?

Japan banned escolar in 1977, and Italy has also forbidden its sale due to the potential for digestive side effects. Some countries, like Canada and Australia, require explicit labeling and provide consumer warnings.

How can I tell if I'm eating escolar instead of tuna?

Given widespread mislabeling, it can be difficult to tell just by looking. Your best bet is to ask the restaurant or fishmonger directly for the species and consider the source. True white tuna (albacore) is the only species legally labeled as such in the U.S..

Can everyone experience keriorrhea from eating escolar?

No, sensitivity varies. While some people are unaffected, studies suggest a significant percentage (45-67%) will experience symptoms. The risk increases with the amount of fish consumed.