Mercury and Fish

          In recent years, the consumption of fish has been widely advocated due to the health benefits associated with omega-3 fatty acids (FAs).  Diets high in fish, however, have also been associated with elevated exposures to toxic chemicals, mainly methyl mercury, and have therefore been linked to adverse health effects.  Such mixed messages have led to much confusion regarding whether or not, or to what extent, fish should be included in one’s diet.  Consequently, many organizations and agencies have published warnings about which fish should be avoided due to high mercury levels.  These messages, however, are limited in that they describe only fish that are bad because of high mercury without describing those that are most healthy due to high levels of FAs.  In this article, I’ve not only listed certain popular seafood to be avoided due to high levels of mercury, but also included fish that are important to good health due to high FA levels.
          For those unfamiliar with the health effects of methyl mercury, this compound is a widely know neurotoxin.  While toxic to adults, it is especially toxic to the developing fetus and therefore should be particularly avoided by pregnant women.  Lower IQ in children whose mothers consumed high-mercury fish while pregnant has in fact been observed in major studies.  Methyl mercury is also linked to heart disease and therefore increased heart attacks.  To the contrary, omega FAs have been shown to improve brain function and reduce heart disease.  This is why it’s important not simply to eat fish low in mercury, but to eat those high in FAs, otherwise you’re missing out on the benefits of fish consumption!  Note that if you don’t like fish, you can still obtain beneficial omega-3 FAs by taking dietary supplements..

High-Mercury (To Avoid):

  • Shark
  • Swordfish
  • Marlin
  • Tuna (yellowfin, ahi, canned albacore)
  • Mackerel (king, Spanish, Gulf)
  • Tilefish
  • Marlin
  • Sea bass (Chilean)
  • Orange roughy
  • Grouper
Low to Moderate Mercury + High-omega FAs (To Eat):

  • Salmon (Atlantic)
  • Herring
  • Trout
  • Flounder
  • Pollack
Other seafood such as tilapia, cod, halibut, lobster, and certain sea bass are okay to eat given their low mercury content, however, since they are not high in FAs, they are not the BEST choices.

If you enjoyed this article and have a Yahoo, Google, or Twitter account, please join my blog!  Here you can leave comments, rather than on the Faecbook group.  Simply click the “join this site” button to the right, log in using your account info, and click “follow publicly.”  Thanks!!

                                                                                                       -Shahir Masri

Comments

Post a Comment

Popular posts from this blog

Climate Change Publication - The Hill

Image
Just had a climate change article published in The Hill over the weekend. The article discusses the connection between climate change and the recent hurricane activity we've experienced here in the U.S. As for the title, there is already a new Hurricane (Maria) tearing through the eastern Caribbean as I share this. According to the U.S. National Hurricane Center, it just made landfall on the island of Dominica as a Category 5. Let's hope for the best for our island neighbors. Hurricanes and the climate – is the worst yet to come? "A few weeks ago we witnessed the dramatic saga unfold in Houston as Hurricane Harvey slammed the Texas coast. Lives were lost and entire neighborhoods vanished. According to scientists, Harvey dumped more rain than any previously recorded storm in the contiguous U.S. This week the nation braced again as Hurricane Irma swept through Florida. Are these storms just a fluke, or a sign of things to come? As a scientist who studies climate change, thi...
Read more

Climate Change #4 – The Tipping Point

Image
If you’ve heard of climate change, you’ve probably heard of the “tipping point.” But what does this mean? To understand, you must first understand earth’s “positive feedback” systems. Let me explain.  Major Positive Feedbacks You’re all familiar with positive feedback mechanisms whether you know it or not. Positive feedback is when a change in A leads to a change in B. And the change in B leads to a further change in A, which further changes B. This goes back and forth as both A and B continuously reinforce each other—a sort of snowball effect. Besides snowballs, earth has some positive feedback systems with tremendous implications to the climate. Let’s take a look at a few and discuss how initial small changes can rapidly get out of control and send things down an undesirable path. Snow Cover – As sun hits earth, some light is absorbed and some is reflected. The pleasant climate we enjoy on earth is the result of a delicate balance between this incoming and outgoing energy. Snow ...
Read more

Your Health - What to Prioritize

Image
             Though this blog mostly concerns chemical exposures, it is critical to keep in mind the more important role that our basic health tenants play in good health. That is, the importance of a healthy diet, exercise, and aversion of harmful habits. While avoiding toxic cosmetics, eating organic, and watching the fish you eat are things certainly worthwhile, and things I clearly advocate, their impact to health is relatively low compared to the impacts of eating well and staying active. This reality is often missed by those interested in health. More tragically, minimizing chemical exposures can give the false illusion of healthy living, when in fact a person is not leading a healthy life. You might say, what good is reducing your late-life cancer risk, albeit by a fraction of a percent, if you’re going down the path of a midlife heart attack?               There was a time when en...
Read more