Understanding the 'Butterfish' Dilemma
The term 'butterfish' can refer to several species, each with a different nutritional profile and safety considerations. The key is differentiating between the true American butterfish ($Peprilus~triacanthus$) and escolar, which is often mislabeled. Black Cod, or Sablefish, is another fatty fish sometimes referred to as butterfish, known for its high omega-3 content. Verify the exact species to avoid health issues.
American Butterfish ($Peprilus~triacanthus$)
This small, flat, silvery fish is found in the Atlantic Ocean. It is considered a safe and sustainable seafood choice. The health benefits below refer to this species.
Escolar ($Lepidocybium~flavobrunneum$ and $Ruvettus~pretiosus$)
Escolar contains high levels of indigestible wax esters. This can cause digestive distress, including oily diarrhea and abdominal cramps, known as keriorrhea. Some countries have issued warnings or bans on its sale.
Nutritional Highlights of True American Butterfish
Authentic butterfish offers various nutrients. A 3-ounce serving offers a significant portion of daily requirements for several vitamins and minerals.
- High-Quality Protein: Essential for building and repairing tissues, supporting muscle mass, and numerous bodily functions. A 3 oz serving provides around 19g of protein.
- Rich in Vitamins: Butterfish is high in B vitamins.
- Vitamin B12: Crucial for nerve function and red blood cell production.
- Niacin (B3): Important for converting food into energy and maintaining nervous system health.
- Vitamin B6: Supports brain development and function, and the metabolism of proteins.
- Essential Minerals: This fish is a good source of minerals.
- Selenium: A potent antioxidant that protects against cellular damage and supports immune function.
- Phosphorus: Vital for bone health and energy storage.
- Low Mercury Content: Authentic butterfish has low mercury levels, making it safe for regular consumption.
Health Advantages of Eating True Butterfish
Including butterfish in a diet offers several health advantages:
- Supports Heart Health: The lean protein and low saturated fat support cardiovascular wellness. Fish consumption is associated with a lower risk of heart disease.
- Boosts Brain Function: The B vitamins, contribute to brain health and cognitive function.
- Enhances Immune System: Selenium helps strengthen the body's immune response and protect against free radicals.
- Aids in Weight Management: High in protein and low in calories, butterfish can promote satiety, helping with weight loss.
- Promotes Bone Health: Phosphorus is essential for strong and healthy bones.
Dangers of Misidentified "Butterfish"
The main health risk comes from mislabeling, specifically the substitution of escolar for true butterfish. Escolar contains gempylotoxin, a non-digestible wax ester that acts as a laxative.
Symptoms of Keriorrhea
- Oily, orange-colored stools
- Abdominal cramps
- Nausea
- Headache
Symptoms can appear a few hours after consumption and resolve within 24-48 hours. The severity varies between individuals.
How to Safely Consume Butterfish
To ensure benefits without risks, follow these steps:
- Buy from a Reputable Source: Purchase from a trusted seafood vendor and ask about the species being sold.
- Clarify Species: Ask if the fish is Peprilus triacanthus or escolar.
- Start Small: Consume a small portion (e.g., 6 oz or less) to gauge your body's reaction.
- Choose Freshness: Opt for fresh, wild-caught U.S. butterfish when possible.
Comparison: Butterfish vs. Other Popular Fish
| Feature | True Butterfish | Salmon | Cod |
|---|---|---|---|
| Mercury Levels | Very Low | Low to moderate | Low |
| Omega-3 Content | Lower (but still present) | Very High | Low |
| Protein per 3oz | ~19g | ~22g | ~19g |
| B12 Content | High | High | Lower than Butterfish |
| Selenium Content | High | High | Lower than Butterfish |
| Wax Esters Risk | None | None | None |
Conclusion
When purchased and identified correctly, true butterfish ($Peprilus~triacanthus$) is a healthy seafood option. Its high protein content, low mercury levels, and rich vitamin and mineral profile make it a beneficial addition to a balanced diet. The potential for mislabeling with escolar, a species that can cause digestive side effects, is a key concern. Careful sourcing from reliable suppliers is key to safely enjoying this fish. For information on species identification and sourcing, consulting resources like the NOAA is recommended. NOAA Fisheries - Butterfish
