Tuna is a convenient and affordable protein source enjoyed by millions of Americans every day. Subway, one of the largest restaurant chains in the country, offers tuna sandwiches and wraps on its menu. But some recent controversies have called into question what’s really in Subway’s tuna and whether it contains concerning levels of mercury. Let’s take a closer look at the facts.
The Mercury Controversy
Mercury is a heavy metal found naturally in the environment that can build up in the tissues of fish. When humans eat contaminated fish, mercury can pose health risks depending on the amount consumed. The developing brains and nervous systems of fetuses and young children are especially vulnerable.
For this reason, the FDA provides guidelines on how much canned tuna pregnant women, women who may become pregnant, nursing mothers and young children can safely eat. Light tuna has lower mercury levels than white and albacore tuna, so the FDA recommends pregnant women eat no more than 12 ounces of low mercury canned light tuna per week.
Subway uses skipjack and yellowfin tuna in its tuna sandwiches and wraps. These are light tuna species that typically have low mercury levels. However a 2021 New York Times investigation found that Subway’s tuna had higher mercury levels than what would be expected based on industry standards and testing of similar canned tuna products.
Subway disputed the findings and stood by the safety of its tuna. So who’s right? Here are the key facts:
-
Average mercury levels in Subway tuna appear low overall – Independent lab tests commissioned by other media outlets detected an average mercury concentration in Subway tuna well below the FDA limit of 1 part per million (ppm) for fish. This suggests that on average, mercury levels do not seem excessively high.
-
But some variability exists – While averages were low a few outlier Subway tuna samples had mercury concentrations approaching or exceeding 1 ppm. This indicates sporadic spikes may occur in some samples.
-
The tuna variety matters – Albacore (“white”) tuna tends to have much higher mercury levels than light tuna species like skipjack. Subway only uses light tuna.
-
Caution is still warranted for vulnerable groups – Because mercury levels can spike in some samples, pregnant women and young children should take extra care with canned tuna intake, including tuna from Subway.
How Much Tuna is Safe to Eat?
For the general population, including children over 6 years old, the FDA says you can safely eat up to 14 ounces (about 4 servings) of low mercury canned light tuna like skipjack per week. Albacore tuna intake should be limited to around 7 ounces (2 servings) weekly.
Here are the FDA’s current tuna consumption recommendations based on mercury risk:
Group|Light Tuna (skipjack, yellowfin) | Albacore Tuna
Does Subway tuna have mercury?
FAQ
Is tuna from Subway safe during pregnancy?
How much mercury is in a tuna sandwich?
How many tuna sandwiches can I have a week?
Is Subway tuna a fish?
The ingredients in Subway’s tuna are “not tuna and not fish,” an attorney for the plaintiffs says.
Is tuna high in Mercury?
Since some tuna species are very high in mercury, a single 3-ounce (85-gram) serving may have a mercury concentration that equals or exceeds a person’s weekly reference dose. Summary Tuna is high in mercury compared to other fish. A single serving of some types of tuna may surpass the maximum amount of mercury that you can safely consume per week.
Does canned tuna have mercury?
About half of people don’t know that different varieties of canned tuna have varying levels of mercury, and 18% don’t know that canned tuna has any. The FDA recently told CR that those levels are “protective of neurodevelopmental effects from a critical window of development for a fetus during pregnancy,” and are also safe for other individuals.
Can you eat tuna if you have low mercury?
You can consume skipjack and canned light tuna alongside other low-mercury species, such as cod, crab, salmon and scallops, as part of the recommended 2–3 servings of fish per week ( 10 ). Try to avoid eating albacore or yellowfin tuna more than once per week. Refrain from bigeye tuna as much as possible ( 10 ).