U.S – Recent tests by Consumer Reports (CR) on canned tuna from well-known brands have revealed variable concentrations of mercury, a poisonous heavy metal present in food, from can to can.
Some tuna cans, in the opinion of CR’s food safety experts, contain amounts of mercury that, if consumed by a pregnant person, could harm the unborn child’s health.
However, CR also discovered that canned tuna, particularly the light types, has generally quite low average mercury levels.
According to CR, the erratic mercury levels discovered from can to can continue to be a worry for vulnerable people.
Mercury is a well-known neurotoxin that is particularly detrimental to young children, although it can also be harmful to adults in high doses.
The toxic heavy metal is of particular concern for pregnant people, due to the vulnerability of their unborn children.
Consumer Reports evaluated ten cans of tuna from a total of five different brands—Bumble Bee, Chicken of the Sea, Safe Catch, StarKist, and Wild Planet— including two varieties of albacore and skipjack.
According to the association, a third of Americans consume tuna at least twice each month, and 10% do so at least once per week.
It analyzed three samples of each product, drawn from various lots, making a total of 30 samples.
Before testing, the water in which all tuna items were packaged was drained.
One in five cans of tuna out of the total samples had mercury levels that were higher than the Food and Drug Administration’s (FDA) recommendation for eating tuna.
The same percentage of tuna cans were found to have elevated mercury levels in 2014, according to CR’s analysis of FDA data.
Another important discovery was that albacore tuna typically contains more than three times as much mercury as skipjack or light tuna.
Albacore tuna had greater mercury levels in CR’s test than light tuna, but certain brands had a considerably wider range than others.
For instance, the albacore tuna from Chicken of the Sea contained ten times as much mercury as the light tuna, although the albacore and skipjack tuna from Wild Planet had comparable mercury concentrations.
The mercury levels in none of the albacore CR examined were low enough for an adult to consume three servings per week. Only Bumble Bee’s albacore had concentrations that would permit two servings each week.
The levels in the remaining albacore tunas only called for one weekly meal, and CR suggests that kids stay away from albacore altogether.
According to CR, all light tuna varieties, except for one, had mercury levels low enough that, provided no other fish is consumed, adults who are not pregnant could safely take three 4-ounce portions a week, while kids could eat two 1- to 4-ounce servings (depending on age).
Last year, the FDA asked the National Academies of Sciences, Engineering, and Medicine (NASEM) to conduct an independent study to assess young children’s exposure to mercury from consuming seafood.
The goal of the study is to present the most recent knowledge on the relationship between eating seafood and a child’s growth and development.
A better scientific understanding of mercury exposure from food is a step in the cycle of continual improvement under the FDA’s Closer to Zero Action Plan.
The study will also shed light on whether the agency’s present recommendations for the consumption of fish by youngsters, women who may become pregnant, and nursing mothers need to be updated.