Mercury in Tuna
Measuring mercury levels in canned tuna.
Canned tuna is a cheap protein source for many Americans but a Consumer Reports investigation has found “unpredictable” spikes of mercury, a neurotoxin that can impact organ functioning and neurodevelopment in children, in some cans.
In total, 30 samples—all tuna products that were packed in water—were tested from each of five popular brands. While the mercury levels were all within U.S. Food and Drug Administration standards, Consumer Reports discovered a wide range of levels among brands and that individual cans can sometimes have much higher levels “that would change the FDA’s recommendation about how often someone should eat that particular tuna.”
Among all brands tested, light tuna had on average three times less mercury than albacore, which comes from larger fish, but, again, some individual cans of light tuna can have higher amounts that would change a recommended safe consumption amount.
According to the report, the findings suggest that it is inadvisable for pregnant women to eat canned tuna, and that developing young children should stick to light or skipjack tuna in limited quantities. Adults who aren’t pregnant can aim for 8–12 ounces per week of fish that is relatively low in mercury. This could include up to three servings of canned light tuna but only one 4-ounce serving per week of albacore (or the amount in a 5-ounce can packed in water).
See also: Mercury in Seafood
Matthew Kadey, MS, RD
Matthew Kadey, MS, RD, is a James Beard Award–winning food journalist, dietitian and author of the cookbook Rocket Fuel: Power-Packed Food for Sport + Adventure (VeloPress 2016). He has written for dozens of magazines, including Runner’s World, Men’s Health, Shape, Men’s Fitness and Muscle and Fitness.
