New Study Links Seafood With High Levels of Mercury to ALS

New Study Links Seafood With High Levels of Mercury to ALS

A new study presented at the 2017 Annual Meeting of the American Academy of Neurology suggests a link between eating fish high in mercury and ALS, also known as Lou Gehrig’s Disease.  ALS is a disease that causes progressive damage to the nuerons that control voluntary muscle movements leading to atrophied muscles that make movement, speaking, eating and eventually breathing difficult.

The study surveyed 518 people – 294 of whom had ALS and 224 who didn’t – and recorded their seafood intake.  Those in the top 25% of eating mercury rich fish were nearly twice as likely to have ALS and 61% of those who had ALS were in the top quarter of estimated mercury intake.

What Fish Are High in Mercury?

While this study in itself isn’t a smoking gun, when added to the growing body of evidence that levels of mercury in fish are increasing, we need to be sure that we are making educated decisions about the fish that we eat.

There are 2 things that you need to know about mercury in fish.  The first is that mercury biomagnifies which means that fish at the bottom of the food chain and that have shorter lives will have less mercury than fish at the top of the food chain or have longer lifespans.  You can see a full list here of the most contaminated seafood but here is a short list.

Seafood with Low Amounts of Mercury

  • Shrimp
  • Salmon
  • Clams
  • Oysters
  • Tilapia
  • Sardines
  • Catfish

Seafood with Moderate Amounts of Mercury

  • Mackerel
  • Crab
  • Trout
  • Lobster

Seafood with High Amounts of Mercury

  • Tuna
  • Marlin
  • Shark
  • Swordfish


The second thing you need to know is that there is also a small but growing opinion in the scientific community that eating fish high in selenium will offset the harmful effects of mercury.  Selenium is an important mineral that helps the brain clear out the toxic Reactive Oxygen Species (ROS) formed in the brain as the cells in the brain resperate.  The mercury binds with the selenium, preventing it from doing its important job.  Eating fish higher in selenium ensues that there is enough selenium left over after all the mercury has bound with it.

The best thing to do is to eat fish lower on the food chain that has been wild caught as that seafood tends to have more selenium than farm-raised seafood.  You can also supplement your selenium or try to eat other foods high in selenium like Brazil Nuts, seeds, beef liver, spinach and eggs.

Sometimes when a new study like this comes out, the knee jerk response is to just swear off seafood but seafood is an important component of any healthy diet but especially a keto/Paleo diet.  After all, remember that seafood was probably our first diet as mankind evolved mainly around large bodies of water.  We have been designed to need the nutrients that seafood provides.  Just be smart; limit your exposure to mercury and maximize your exposure to the selenium that protects you and you will be fine.

Don’t miss a post! Click here to sign up for our daily email!

Need more info about the ketogenic diet? How about a great support group? Join our Ketogenic Facebook support group!

2 thoughts on “New Study Links Seafood With High Levels of Mercury to ALS

  • Thank you for sharing this post about seafood with high levels of mercury. This is a very informative post especially to those who are trying to conceive or are already pregnant. These high mercury seafood should be avoided at all cost because it can harm our bodies. Hope everyone are aware or could be aware of this.

Leave a Reply

Leave a Reply

Your email address will not be published. Required fields are marked *

You Can Support The Blog By Donating Through Paypal
Disclaimer:  While every effort has been made to ensure the accuracy and effectiveness of the information displayed on this website, My Sugar Free Journey makes no guarantee as to the procedures and information contained within. The publisher of this website will not be held liable for direct, indirect, incidental or consequential damages in connection with or arising from the use of information displayed on This website is not intended to be a substitute for the advice of a medical professional.
Please note that any content created and/or advice followed using the methods suggested or any products recommended on will be done so at your own risk.
Please note: Posts may contain affiliate links or sponsored content. For more of our privacy and cookie policy, click here.
© 2015 - My Sugar Free Journey All Rights Reserved. No content on this site may be copied and reused in any form or fashion without express written permission.