Is Subway Tuna Real Tuna?
A lab test found no tuna DNA, headlines went everywhere, a lawsuit followed. Then the science was explained and the case collapsed. Here is what the evidence actually shows.
This one is worth walking through properly, because the reason the story spread is that the finding sounds damning and the explanation sounds like a corporate excuse. It is not.
What actually happened
In January 2021, two plaintiffs filed a class action in a US District Court alleging that the tuna was not what it claimed to be. In June that year the claim was narrowed to a different allegation: that the species named, skipjack and yellowfin, were not present.
Then a newspaper had samples from several Los Angeles locations tested at a commercial lab. The result, widely quoted ever since, was that the lab could find no amplifiable tuna DNA.
That phrase did an enormous amount of work in headlines it was never able to support.
Why the DNA test could not find tuna
Standard DNA testing identifies a species from intact genetic material. Cooking destroys it. Heat breaks DNA into fragments too short and too damaged for a standard test to read.
Subway’s tuna is cooked before it is canned and cooked again in the retort process. By the time it reaches a sandwich there is no intact DNA left to amplify, regardless of what fish went in.
LeeAnn Applewhite, who founded a specialist food testing lab, explained that the retort process degrades and fragments the DNA, and that identifying cooked tuna requires proprietary primers built to target those short fragments, which took her lab around fifteen years to develop.
Subway made the same argument at the time, saying DNA testing is not a reliable way to identify denatured proteins and that the testing did not show there was no tuna, only that it could not confirm tuna, which is what you would expect.
The test that was designed for cooked fish
A few months before the newspaper report, that specialist lab had tested Subway tuna for a television program using methods built for processed product.
Across roughly 150 pounds of product and 30 separate tests, the lab reported detecting skipjack tuna, yellowfin tuna, or both species, in every sample.
That is the test that could actually answer the question, and it answered it.
What happened to the lawsuit
| Date | What happened |
|---|---|
| January 2021 | Class action filed alleging the tuna was not as advertised |
| June 2021 | Claim amended to allege the named species were absent |
| Late 2021 | Judge Jon Tigar dismissed it for failing the heightened pleading standard for fraud, with leave to amend |
| July 2023 | The remaining plaintiff moved to dismiss the case for personal health reasons. It ended with prejudice, meaning it cannot be refiled |
The judge’s reasoning on the first dismissal is worth quoting because it is often misreported as a ruling on the tuna. It was not. He wrote that Subway cannot properly defend itself against a complaint that does not identify the misstatements it allegedly made. The plaintiffs had not specified which statements they saw, when, or where.
No court ever found that the tuna was not tuna. The case ended without a settlement and without a finding against the company, which then sought its legal costs.
So what is in it
Subway states that it serves 100 percent real wild caught tuna, mixed with mayonnaise. Skipjack and yellowfin are the two species it names, and both are standard commercial canned tuna species used across the industry.
The tuna salad is prepared in store by draining the tuna and mixing it with mayonnaise, which is why texture and mayo ratio vary noticeably between locations. That variation is a preparation difference, not an ingredient one.
Why the story stuck anyway
Three reasons, and none of them involve the fish.
The phrase was perfect. No amplifiable tuna DNA is memorable, sounds scientific and appears to say the opposite of what it means. Corrections never travel as far as the original.
Subway’s denial sounded like a denial. Explaining that a test has methodological limits is exactly what a guilty company would also say, so the accurate response was indistinguishable from a bad one.
People already had questions. Tuna salad at a low price point invites suspicion, and the story landed in ground that was already prepared.
If you want to check the current ingredients and nutrition for yourself, they are on the Subway menu.
Related Questions
Is Subway tuna real tuna?
The available evidence says yes. Subway states it serves 100 percent real wild caught tuna, and a specialist lab using methods designed for cooked fish detected skipjack, yellowfin or both in all 30 samples it tested. No court or regulator has ever found otherwise, and the lawsuit that alleged it was dropped in 2023.
What did the no amplifiable tuna DNA test actually mean?
It meant the lab could not identify any species, not that tuna was absent. Cooking and the canning retort process break DNA into fragments too damaged for a standard test to read, so a cooked tuna sample from any brand would be expected to give the same result. It was a limit of the method, not a finding about the product.
What happened to the Subway tuna lawsuit?
It was filed in January 2021, dismissed later that year for failing the heightened pleading standard for fraud because it did not identify the specific statements at issue, and finally dropped by the remaining plaintiff in July 2023 for personal health reasons. The dismissal was with prejudice, so it cannot be refiled, and there was no settlement.
What kind of tuna does Subway use?
Skipjack and yellowfin, the two species it names publicly. Both are standard commercial canned tuna species used widely across the food industry. The company describes the product as wild caught, and it is mixed with mayonnaise to make the tuna salad.
Why does Subway tuna taste different at different stores?
Because the tuna salad is mixed in store. Staff drain the tuna and combine it with mayonnaise, so the ratio, the texture and how recently it was made all vary by location and by shift. That is a preparation difference rather than a difference in what is being used.
Can DNA testing identify cooked fish at all?
Yes, but not with standard methods. It requires primers developed to target the very short DNA fragments that survive cooking and the canning retort process. Labs that specialize in processed seafood have built those tools, which is why one lab could identify the species and another reported nothing.
Did Subway win the tuna lawsuit?
The case ended in the company’s favor in the sense that it was dismissed with prejudice with no finding against it and no settlement, though it was withdrawn by the plaintiff rather than decided on the facts. Subway subsequently sought recovery of its legal costs from the plaintiff side.
More on Subway
About this guide. USA Food Menu is an independent reference site and is not affiliated with Subway. This page summarizes published reporting on the 2021 to 2023 litigation and the laboratory testing around it, and describes the United States. Ingredients and suppliers can change, so check current allergen and ingredient information directly with the chain. Prices and nutrition are on the Subway menu.
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