The question, "What percent of tuna is Subway tuna?" came to a head in a 2021 lawsuit that captured significant media attention. In the suit, plaintiffs initially claimed that the product contained no tuna at all. The core of the issue was that some independent lab tests, notably one commissioned by The New York Times, failed to detect any amplifiable tuna DNA in samples of the sandwich filling.
The Problem with DNA Testing Cooked Fish
Subway and food science experts quickly countered that these initial test results were misleading. The cooking process, which involves subjecting the fish to high temperatures, can denature the tuna's DNA, meaning the genetic material is altered and fragmented. This makes it extremely difficult, if not impossible, for standard PCR-based DNA tests to identify the species. The lab that conducted The New York Times test even acknowledged this as a possibility, stating it couldn't identify the species.
Subway's Defense and Counter-Evidence
In response to the lawsuits and public skepticism, Subway has taken several steps to defend its product's authenticity.
- Official Statements: The company has repeatedly stated that it uses 100% wild-caught tuna, specifically skipjack tuna.
- Website: Subway launched a dedicated webpage, SubwayTunaFacts.com, to address customer concerns and provide information about its sourcing and quality control.
- Third-Party Lab Tests: The company points to tests conducted by Applied Food Technologies (AFT), a lab specializing in seafood analysis. These tests found evidence of skipjack and/or yellowfin tuna in every Subway sample tested.
- Sourcing Information: Subway disclosed that its tuna is sourced from reputable global suppliers who must provide documentation tracing the fish from its origin to the restaurant.
The Dismissal of the Lawsuits
Perhaps the most compelling evidence for Subway's claim comes from the legal system itself. The initial lawsuits questioning the tuna's authenticity were ultimately dismissed by a federal judge in 2023. The court found that the plaintiffs' claims lacked merit and supporting evidence, calling the litigation a "reckless and improper lawsuit". While one plaintiff initially withdrew, the lawsuit was eventually dismissed with prejudice, preventing it from being refiled.
Comparison: Subway vs. Canned Tuna
To understand the quality difference, it's helpful to compare Subway's product to what you might buy in a supermarket.
| Feature | Subway Tuna Filling | Standard Canned Tuna (e.g., Chunk Light) |
|---|---|---|
| Tuna Quality | Typically uses processed, wild-caught skipjack flakes. | Often uses lower-grade, smaller pieces of tuna; can be skipjack or other species. |
| Added Ingredients | Mixed with mayonnaise and flavor-protecting additives by employees. | Typically packed in water, oil, or brine with minimal other ingredients. |
| Processing | Highly cooked during processing, which can denature DNA. | Processed and cooked, but less intensely than restaurant-style paste. |
| Source | Sourced from global suppliers with traceability documentation. | Sourcing varies widely by brand; some have sustainability initiatives, others do not. |
| Format | Prepared as a paste-like salad, mixed with mayonnaise. | Comes in solid, chunk, or flake format for versatile use. |
The Tuna That Isn't Tuna: Legal Context
The Subway tuna controversy isn't the first time a fast-food item has faced scrutiny, but it is notable for the specific nature of the allegations. The legal case hinged on the claim of "economic adulteration," suggesting cheaper, non-tuna substitutes were used. While this was the initial accusation, it became difficult to prove, especially with contradictory lab results and the challenge of testing processed fish. The dismissal of the case reinforced Subway's public stance, though lingering doubts and social media rumors persist. The episode serves as a powerful reminder of how food processing methods can impact public perception and scientific testing, even when a company maintains its product's authenticity.
Conclusion
Despite sensationalized media reports and class-action lawsuits, Subway's official stance, backed by legal dismissals and specialized lab tests, is that its tuna is 100% real, wild-caught tuna. The perception that it might not be real largely stems from the technical challenges of DNA testing highly processed fish. While the product is a tuna salad mix that includes mayonnaise and other ingredients, the seafood component itself is confirmed to be tuna. The controversy has been a potent case study in food transparency, brand trust, and the science behind food processing, but the legal and scientific evidence ultimately supports Subway's claim.
