Mercury Poisoning: Why Consuming Fish Can Be Toxic to Your Health

Nutrition Advice

About 1 year ago I found out that my I had mercury poisoning. Yes, really!

In my past I was a typical teenage fad dieter who believed that the tuna salad was the healthiest skinny meal to have! And that sashimi was even skinner for dinner. Anything that made me skinny was delicious. So I consumed a can of tuna everyday for lunch, everyday! And sometimes for dinner! When dining out, my choice would always be Japanese. So at least 1-2x/week I was consuming a great deal of sushi and sashimi. But thats so healthy right?

But then…

I went for my annual blood and hair mineral analysis tests and my doctor who knows my life is dedicated to health, was quite frightened by the pathology statistics. I never really understood just how toxic fish could be….

Heavy metals can be detrimental to your health which you will read below. Since finding out my results I have cut out tuna almost completely ( tuna is the highest source of mercury along with other fish) and with some liver support ( heavy metals get processed through the liver), my mercury levels are slowing going down…

My nutrition idol, Celebrity nutritionist, Kimberly Snyder explains all of this perfectly in her article. 

You’ve heard it all before—fish is a great way to make sure you’re getting your omega-3s for beautiful skin and heart health, among other perks. It seems a “cleaner” option then the ‘ol chicken or red meat on the menu.

The only problem with that is…with those omega-3s, you’re getting more toxins than ever these days. It’s the sad truth of our polluted waterways and oceans, and our fish friends act as virtual underwater filters. Mercury and PCBs abound in seafood (in some fish more than others), so you should certainly not pile on the seafood as a daily component of your diet. The good news is that some fish contain lesser amounts of toxins, so if you are a fish-eater/love you can be more strategic in your choices and fare far better! Also, please read to the end of this blog, and you’ll see tips for those that want to keep fish in their diet, to maximize health and safety.

Fish with the Highest and Lowest Mercury Content

Not all fish are the same in their toxicity levels. The National Resources Defense Council states that the most polluted fish include:

  • Swordfish
  • Mackerel (king, Spanish, and gulf)
  • Orange roughy
  • Tuna (bigeye, ahi, canned albacore, and yellowfin)
  • Shark
  • Tilefish
  • Marlin
  • Bluefish
  • Chilean sea bass
  • Grouper

It’s funny because I went to a sushi restaurant a few days ago with friends (seaweed salad, veggie rolls for me) and forbade my friends from ordering their usual yellowfin sashimi. There was a whitefish on the menu that they switched to instead. Whew!

Some of the popular seafood picks, including mahi-mahi, lobster, halibut, Alaskan cod, black and striped bass, and Atlantic and Pacific halibut, are considered “moderately” contaminated with mercury, and the NRDC recommends eating them no more than six times per month. Isn’t “moderately contaminated” a funny term? It’s like saying, well, it’s okay to just eat a teeny bit of rat poison- but not too much!

Some of the fish that have been shown to be lower in heavy metals and toxins include (this doesn’t mean heavy-metal free, but at least lower lowers displayed in some research):

  • Wild Alaskan salmon
  • Sole
  • Tilapia
  • Trout (freshwater)
  • Haddock
  • Whitefish
  • Anchovies
  • Perch
  • Squid
  • Mullet
  • Scallops
  • Sardines
  • Domestic crabs

Mercury comes with a whole lot of nasty side effects if you get too much as an adult, a mom-to-be, or a child. Since you can’t detect it on your own by smell or taste, it’s important to educate yourself on the types of fish it’s safest to eat and the ones you should avoid at all costs.

Mercury is a neurotoxin. The NRDC lists memory loss, blood pressure regulation, numbness in the toes and fingers, heart disease, vision loss, and tremors as effects mercury can have on adults. For pregnant women, the exposure could cause mental retardation, cerebral palsy, deafness, or blindness in the child. A study found lowered IQ levels and issues with language, attention, memory, motor skills, and visuospatial functioning in children whose mothers ate fish high in mercury during pregnancy. There are safer ways to get omega-3s and protein for moms-to-be (and everyone else, too!), and they don’t even involve supplements!

In children, there can be all kinds of delays in their development when exposure to mercury occurs.  They may not walk or talk as early as they should, and their learning abilities could be impaired when exposed to even small amounts. Because children’s brains develop so quickly and their bodies are growing and learning so much in the first six years of life, they are especially susceptible to the effects of mercury.

It’s Not Just Mercury. There’s Other Nasty Stuff in Fish, Too.

A lot of what we hear in regard to the dangers of fish revolves around the presence of mercury in their fat and flesh. However, there are also PCBs (polychlorinated biphenyls) and viruses to think about. PCBs are chemicals that were released into the air, water, and soil by industries from the 1920s until they were banned in 1979. Though they can be broken down in the environment (especially in sunlight, though it still isn’t easy) and they haven’t been used in decades, they’re still around and able to cause problems because they’re still hanging around in the fish we eat. The big fish eat the little fish that have PCBs in them, then the even bigger fish eat those, and the PCBs just accumulate over time, working their way up the food chain.

In adults, exposure to PCBs has been linked to memory problems, sexual and fertility issues, and cancer. If a child has too much exposure (inside the womb or later), his IQ and memory can suffer.

A study involving people from the Great Lakes basin area, where fish consumption is higher than average, found that those men and women had heightened risks of cancer, immune and endocrine system troubles, non-Hodgkin’s lymphoma, diabetes, and liver disease after the reproductive years (the study did not find conclusive evidence that PCBs caused reproductive issues, but said that reproductive function “might” be disrupted and would require further study).

The Office of Environmental Health Hazard Assessment of California offers a few tips for making fish safer to eat (though you’re still not going to be able to remove all the toxins), like:

  • Trim the fat.
  • Remove the skin.
  • Clean and gut the fish before cooking it.
  • Don’t eat the liver of the fish or the soft green parts of crabs and lobsters.

(See more tips from me, below).

As with the mercury, the bigger, fattier fish are the ones to watch out for when you’re worried about PCBs. The Environmental Defense Fund has a chart that shows how often it’s safe to eat certain types of fish for men, women, older children, and younger children, and states whether the concern is mercury, PCBs, or both.

Viruses and Government Cover-Ups

Viruses are another issue, and they’re generally a man-made one. The film, Salmon Confidential, discusses the effects that salmon farms may have had on wild salmon along the Fraser River in British Columbia. The wild salmon passing through the areas where salmon are farmed are potentially picking up deadly (to them) diseases—infectious salmon anemia (ISA), salmon alphavirus (which damages the salmon’s pancreas), and piscene reovirus, which weakens the heart (turns it to mush, actually), making it impossible for these once powerful fish to swim upstream.

Some of the farmed salmon carry disease all the way to the store, based on the samples biologist Alex Morton from British Columbia gathered—and they’re being sold as food in the supermarket when they have these diseases. Morton sent a salmon sample in for testing, straight from the supermarket, and it came back positive for piscene reovirus. I know- this is an absolute outrage!! I know we would all like to believe that what we buy in the supermarket is always safe, but it is sadly, not so.

Instead of addressing the problem as if it were a real threat and allowing scientists to investigate, the Canadian government muzzled anyone who wanted to say the farmed salmon were infected and the cause for the decline in wild salmon. While studying the decline of wild salmon, scientist Kristi Miller’s research led her to the salmon farms. She was forbidden to test the farmed salmon (or speak out at all about it—no interviews, no meetings, nothing). The government allows farms to keep disease information confidential from the public and scientists. (What the heck is up with that??!!)

The unwillingness to do anything but cover up the issue puts the ecosystem—and um, our health—at risk, all for the sake of not interrupting trade (and cash flow). So far, the viruses are reportedly not affecting humans, but who knows what the future could reveal? What happens when a virus has been kept alive at cold temperatures on sushi and then you consume it?

If you want to eat salmon, look for the redder fish without visible white fat stripes. The paler, fattier fish are the farm-raised ones, and they’re the most likely to have the infections. (This isn’t a surefire test as some salmon is dyed to look darker, but it is at least one thing to look for).

Other Omega-3 Sources

Obviously, you still need omega-3s in your diet, even when you’re consciously limiting your intake of fish. You can get omega-3s, however, from Beauty Food sources, like flaxseeds, hemp seeds, chia seeds. Just one or two tablespoons a day will give you what you need for healthy brain and nerve function. I’d like to point out that dark leafy green vegetables contain omega 3 fats as well- especially when ingested in large amounts, such as blended into a GGS.

Walnuts are another option, since their omega-3 content is higher than any other type of nut. Try them used in place of ground beef in the Raw Taco Mexican Salad Meal.

If you love Brussels sprouts (as I do), a cup and a half of them will meet your daily omega-3 requirement. Are you shocked? Leafy green vegetables are full of happy surprises!

But What If You Don’t Want to Give Up Fish?

I know. You’ve given up dairy and burgers and now…fish? Heck no! I have to eat something in restaurants, you may be somewhat annoyingly muttering to yourself. I hear it all the time from my clients, and I understand the social and familial complications that can be involved (though it’s possible to eat out without animal foods all the time.  In the Glowing Lean System I take you through the best way to order out of many restaurants- from Mexican to American, etc. I do it all the time). If you truly love eating fish and don’t want to give it up, there are a few things you can do to lower your exposure to the toxins.

When you do eat fish, make sure it’s baked or broiled so the fat (which contains most of the toxins) is drained away. Don’t choose pan-seared or fried because those methods won’t remove the fat. Be selective in the type of fish you eat (see the list above!), but still try not to eat it more than twice per week.

Try to avoid sushi as much as possible. In a perfect, toxin-free (and virus-free) world, sushi and sashimi would be some of the healthiest ways to eat fish. But since you’re eating it raw, all of the nasty stuff that goes along with fish these days is still present. If sushi’s your favorite food and you don’t want to give it up, try trading in your tuna and salmon, some of the most common fish used in sushi, for others from the list that are less contaminated.

You don’t have to give up anything you don’t want to; just be aware of the concerns so you can make educated decisions on the types of fish you consume and how often you eat it. Try to supplement your omega-3 fatty acid consumption with some of the options I listed above, and have fish only a few times a month or a couple of times per week.

If you are a fish-eater, eat lots of cleansing herbs, especially cilantro, which can help chelate (bind to and escort out) heavy metals out of your body. Throw some in your GGS!





Swisse Skincare




Gaia Retreat & Spa


The Healthy Life


JSHealth Vegan Meal Plan


JSHealth Travel Plan




14 Day Slim Down Plan - 2 weeks to a leaner you!


The JSHealth Shopping List - Stock up on these foods for a healthier household


Nutrition 101 - A step by step nutrition guide to optimal health


Emotional Eating Guide - Learn how to rebuild your relationship with food and your body


The Clean Life - An Expert Guide To Health From The Inside Out


Restart Plan - Cleanse your system in 2 - 4 weeks & reveal a slimmer, healthier you


JSHealth Partners


Hi Jessica, I believe in synchronicity so when I was guided to you .on FB I was intrigued and inspired. I turned 46 last week and my husband bought me your book. I wanted to thank you for sharing your wisdom in such a beautifully presented way. My  copy is now filled with tabs and post it notes with actual notes throughout. I am dairy intolerant since having my gallbladder removed 15+ years ago, I don't eat meat, very minimal gluten and was told 12 months ago my gut was not digesting my food properly so I wasn't receiving sufficient nutrients and taking supplements would be a waste of time.  My weight fluctuates tending to gain rather than lose but now I believe I have a tool to help me bring my body back into balance that I need for my health and longevity of life - so again thank you. The first few steps to creating a stronger path forward for my health has found its foundation in your beautiful book, The Healthy Life.

With kindest regards Samantha

I'm writing this email because I wanted to tell you how much I love your blog and how you really helped me in my health journey. Thank you for sharing all your advices and experiences.

When I started my studies, I was drinking lots of coffee and I was eaten the wrong foods, and feel bad about it, I wasn't at my best. So I had done some research on the net but at first I didn't found advices that are for me, and then I found your blog. It was exactly what I was looking for, good advices and healthy recipes. Now I'm following your advices on rest more, and snacks between meals and prep the meals and take time for myself to reconnect with my body and let go my anxiety, etc, and I have a more balanced life and have a new relationship with food thanks to you.

I bought your book and it's honestly the best book I have ever bought. I suffer from IBS and anxiety. I have paid so much money seeing naturopaths however after reading your book and all of your tips I'm noticing so much of a difference, so simple and easy to follow. And symptoms have dramatically decreased. Also you have helped me to relax. Currently drinking the protein health smoothie! Thankyou your amazing.


Hey Jessica!
I haven’t yet brought ‘The Healthy Life’, but I do have the clean life and your slim down plan! I would like to thank you so much for the knowledge your share and the message you put across about health and wellness. I’m studying Nutritional Medicine in Melbourne and absolutely love the philosophy that you share with your JSHealth community. The work you’ve done to show people that leading a healthy lifestyle isn’t boring, tasteless, difficult or depriving is amazing and hope to share the message myself one day. You’ve inspired me to start my own blog , to share the message and have taught me so many things about my own health! You should be proud of your achievements! Thank you again

- Jacinta

I searched for help and tips through the Internet and found Jessica Sepel. This is seriously not exaggerated, but she was the reason why I have dared myself to eat again, to have snacks in between, to nourish my body. I could slowly improve my negative thoughts about my body image and my stupid anxiety of gaining weight. Besides, The Cleanest Gut was awesome too! A huge thank you! Especially from my mum. Seriously, without you I wouldn’t be where I am now!


Congratulations on your new book! It looks absolutely gorgeous. I’ve been following you on Instagram for a few years and you’ve inspired me to slowly but surely eat healthier without giving myself a hard time when I don’t. It made me so happy (and weirdly proud) to see the Daily Mail article on The Healthy Life. I remember trying out your recipes before you even had your eBook out! I can’t wait to get my hands on the book. Keep up the great work.

– Sophie

Cooking in this way truly brought out the foodie in me and has instilled a huge passion for health and wellness! Life throws you hard and frustrating things sometimes but I truly believe that this is where we learn more about ourselves and what our passions in life are! Thank you for inspiring me on my journey to health and wellness!


I am a yoga teacher in Johannesburg and am thrilled to have bought your book today. I love making healthy, nutritious food for my family, friends and fellow yogis! Thank you for this book and your inspiration (had to share a pic of my book on my recipe stand in the kitchen).

– Helene

I bought your beautiful book during the week and told my bestie to go out and buy it also! I love love love it. It is the book I would give to my younger self if I could (I am 41 years old). Everything is just so sensible and informative and is definitely a book all teenagers should have. This should be a text book for girls becoming teens. I will love going back and re-reading it many many times and can't wait to make more of the recipes. Thank you Jess - you are an incredibly inspiring woman and you should feel so proud

Michelle Curtis

My fiancé bought your book and we have cooked some of your meals. Amazing! I love your outlook on a healthy lifestyle and your hints and tips with preparing tasty meals are fantastic. Thanks for reviving us to live a healthier lifestyle and get our bodies wedding ready.