Canned Tuna Mercury – What You Should Know

Mercury in Seafood

Reports coming from both the EPA and FDA in 2010 alerted the public to the problem with high levels of mercury in a wide variety of fresh and processed seafood. As seafood is a recommended part of a healthy diet, this discovery can be disheartening and worrying for many seafood lovers. But how far does this extend? Is it only fresh-water fish or does it include processed fish? And what about fan favorites? What about canned tuna, mercury and possible health risks?

What Is the Concern?

Mercury is an element that is used in a variety of products, such as dental fillings and some

Mercury Rising - What You Should Know about Tuna

thermometers. This element is extremely toxic, and the handling or ingestion of it can cause mercury poisoning, which is very dangerous to the human brain and nervous system. Excessive exposure, particularly in certain demographic groups, can cause severe complications and even death.

In terms of the seafood industry, many fish have some form of mercury in their systems from natural causes or due to the contamination of food on the ocean floor that they consume. When larger fish eat smaller fish, the amount of mercury increases. There is a health concern to these high amounts, especially for those women who are pregnant, mothers who are nursing and small children.

Canned Tuna

Canned tuna is easily a quick and healthy fix for getting the right amount of fish in a healthy diet. But the reports from the Environmental Protection Agency and that of the Food and Drug Administration highlighted that the amount of mercury that tuna and other sea life carry could be higher than normal and that could cause health issues with people who eat it.

As mentioned, the high risk group are those who are pregnant, nursing, or small children, but the risk is still present for anyone who enjoys tuna. While light tuna is considered to lower in mercury content, other tuna such as white tuna, like albacore or yellowfin, have higher amounts of mercury within them.

The problem with the report is the conflicting decisions between the EPA and the FDA, with the actual safe amount that a person can ingest mercury. The FDA has a higher standard of mercury consumption and for canned tuna, at least, the light variety meets those standards. The EPA however, which counts rivers and streams as part of their regulations, thinks a much lower consumption to be better. While these two conflicting ideas may be confusing, it's ultimately up to the consumer to which standard they would like to follow.

Foods That Are Okay

With the containment of mercury in some fish, consumers are concerned about which seafood is safe to eat. It is important to note that small trace amounts of mercury do not harm the body; it is only the higher levels that are considered toxic and detrimental to your health. Below is a list of seafood and fish that have been identified as having low traces of mercury and are safe to eat:

  • Anchovy
  • Clam
  • Domestic crab
  • Catfish
  • Herring
  • Oyster
  • Tilapia
  • Trout

There are other fish that also have slightly higher elements of mercury, but can be eaten six times or less within a month. These fish include:

  • Bass (black or striped)
  • Halibut (Pacific)
  • Lobster
  • Mahi Mahi
  • Canned Tuna

Again, some of the moderate mercury levels of fish are still okay, but due to the process in which they are captured or prepared for delivery are cause for concern.

Fish that are extremely high in mercury and should be avoided include shark, swordfish, marlin and king mackerel.

References

What You Need to Know about Mercury in Fish and Shellfish from the US EPA, https://water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_index.cfm

Mercury Contamination in Fish from the NRDC, https://www.nrdc.org/health/effects/mercury/guide.asp

Too Much Mercury in Canned Tuna – Or Is There? from Business Week, https://www.businessweek.com/lifestyle/content/healthday/635854.html

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