dangers of fish oils

I swear since Things 1-3 arrival I wake up ever earlier and strangely, this morning, as I sip on raw milk Chai Masala (heaven in a cup) in my freakishly chilly yet very fresh mountain home looking overlooking the greenery and splendor of Harissa, Things 1 and 2 happily sleeping in their Pack & Play next to me (Thing 3 doing well and about to be released from the hospital this week….FINALLY…. ), I am reminded of how when I am enjoying the moment instead of pondering my “next move” in life, I am more centered and at peace.

With that “thought for the day” I am about to rock your world (and make a LOT of enemies in the bargain I am certain) when I tell you that fish oil supplement (or cod liver supplement) you take daily for your boost of Omega-3 may not be doing you as much good and may even be harming your health.

Are you still with me or have you run screaming from the room?

In our last segment we discussed the dangers of PUFAs.  I loved some of the comments I got from people that just couldn’t wrap their head around how grains and nuts quite possibly are not the best food choices (gasp) for health.  Some even insisted these things could even be healthy for you.  I get it, I do.  I “drank the kool-aid” as I went through my nutrition training too.  Even as I studied Integrative and Functional Medicine, I fell head over heels in love with eating bushels of nuts, nut milks in lieu of dairy, nut pates and even (the greatest heresy of all) Vegan Cheesecake.  (Sorry beauties, for all of you out there happily delving into your nut “cheeses” I have to say, there is nothing better than REAL cheesecake!)  I ate beans by the truckload (still eat a few in small amounts), and for someone to tell me I didn’t have to give up or cut down on grains…. it was Nirvana.  Nirvana until a year later I found my triglycerides were through the roof and I had a rip roaring zinc deficiency.

That should not have happened on a predominantly raw vegan diet.  And before I get comments like “Oh this is your detox phase.”, let me assure you, I gave this more than a good college try.  My nails were breaking; nay, peeling and breaking.  My hair no longer had a shine, my skin had lost its lustre.  I’m sure there are those that thrive but I am a firm believer estrogen dominance, an intestinal tract with micro tears, and vitamin and mineral imbalances catch up to you eventually.  Metabolisms will slow down even if you are a lean, mean, fighting machine now.  PUFAs, in vast quantities or bad combinations, are now and will always be bad news.


That brings me to the obsession people seem to have with taking handfuls of fish oil.  Wild Alaskan salmon oil, cod liver oil, even krill oil figure heavily in the rota of endless supplements people reach for these days.  But is this habit really helping really helping your cardiovascular health, moods, periods, or the countless numbers of conditions they claim to treat?  The facts might shock you.

The Rancid Truth

If you are an avid reader of The Detox Diva then you know I advocate an Omega-6 to Omega-3 balance of 1:1 in order to prevent and treat diseases such as cardiovascular, cancer, autoimmune illness, thyroid issues, estrogen dominance and many other health problems.  Many people take vast amounts of fish oils in hopes of balancing what is upwards of 16:1 (in favor of Omega-6) in a Standard American Diet.  The problem begins in the processing, manufacturing, and selling of these fish oils.

Fish oil is rich in Omega-3, rich in DHA and EPA , which is a polyunsaturated fat this means the fat molecule has more than one hydrogen bond and those bonds are not that strong in the presence of oxidation meaning they are highly unstable.  When digested, the bonds are easily broken creating free radicals.   The body is able to stabilize or scavenge a small number of these free radicals with antioxidants such as superoxide dismutase, catalase and glutathione peroxidase and even cholesterol and uric acid.

These fragile oils start to oxidize very quickly once manufactured and, since most sit in warehouses (many lacking in climate control), and on shelves for months, the chances that the fish oil is already rancid is very high.   The Crop and Food Research Institute in New Zealand tested a large number of brands from around the world and found the majority had begun the oxidation process.  To say taking rancid fish oils will not benefit those that take them is an understatement.  Rancid fish oils can actually increase risk of atherosclerosis and thrombosis (hardening of the arteries and dangerous blood clotting that could lead to death).  That’s a bad thing especially since many take these supplements assuming it is reversing that risk.

Interesting factoid::  Fish oil has been used by various industries as paints and varnishes for its ability to oxidize and therefore polymerize quickly.

Rancid fish oils has been linked to accelerated aging as a result of their creation of “age pigment” cells.  These types of cells contribute, over time, to degenerative diseases such as liver disease (especially contributing to NAFLD or non-alcoholic fatty liver disease), heart disease, neurological disorders , and has even been linked to Alzheimer’s Disease.

This rancidity also leads to a weakened immune system causing a reduced ability to fight off viral and bacterial diseases.

The Journal of American Medical Association (JAMA) conducted a review of 20 studies finding that neither eating fish nor taking fish oils as supplements reduced the risk of heart attack, stroke, or death.

For those of you who are taking fish oils to increase brain power or prevent cognitive decline studies published on behalf of the Cochrane Collaboration came to the conclusion that fish oil pills failed to treat or prevent cognitive decline.   Although many studies have linked consumption of fish oil to reduced depression, a 2011 meta-analysis by Yale University researchers debunked the idea that omega-3s alleviate any depressive episodes.  For those of you who believe you are getting results from fish oils, I would urge you to check your sources of fish oils and keep them refrigerated at all times.

I know most of you would say this is alarmist but rancid oils are toxic and like it or not, fish oils are often rancid before they hit shelves.  I don’t make the rules.

Side effects

More people than I want to imagine claim they suffer from the fish oil “burps”.  Let’s face it, a lot of fish oil repeat on you and when it does, it’s just not pretty.  nausea, diarrhea, loose stools, decreased appetite, constipation, vomiting and fat in the stool. These gastrointestinal side effects can be minimized if fish oils are taken with meals and if doses are started low and gradually increased but if fish oils are rancid, the chances that these side effects will continue is great.

Omega-3 fatty acids has been linked to increased blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and for those taking drugs, herbs, or supplements that affect blood sugar. If taking fish oils with hypoglycemia or diabetes, have blood sugar monitored by a health care professional on a regular basis.
Omega-3 fatty acids may increase low-density lipoprotein cholesterol levels (LDL) and can worsen symptoms for patients with ventricular tachycardia, increase the risk of bleeding, and may decrease blood pressure.
Fish oil taken over a long period of time may cause a deficiency of vitamin E and may increase the risk of vitamin A or D toxicity so avoiding high doses are imperative..
People with hormonal imbalance or those undergoing hormone replacement therapy should use cautiously, as decreased estrogen receptor production (making it impossible to metabolize estrogen at healthy levels) has been associated with fish oil supplementation.
Patients with asthma, inflammatory bowel disease, or liver disease, or those at risk for colon cancer should seriously consider leaving the fish oil supplements behind based on potential adverse effects associated with fish oil use.
If all of this weren’t enough, think of mercury toxicity.  All wild caught fish and shellfish have some form of mercury.  This shouldn’t stop you from eating it in small amounts (especially with cilantro which can help chelate mercury out of the bloodstream) a few times a week but mercury is mercury and in many supplements claiming to be from wild caught fish or krill, and because mercury is present in the “fat” of the fish (and the fatty tissue is where much of the oil is derived) mercury can occur at at an exponentially higher level.
Please understand that much of the fish oils (especially cod liver oil) is manufactured from farm raised fish and these fish are often fed grains and other “bits” that raise the Omega-6 levels to less than optimal ratios to Omega-3 basically nullifying any positive effects from fish oil.

Sustainability issues

Because the demand for a “quick fix” for a host of health issues that fish oils claims to treat has reached a fever pitch, manufacturers of fish oils (especially those deriving their fish oils from Menhaden) are guilty of dramatic overfishing disturbing the life cycles of many water ways..  Many Atlantic states have banned fish oil producers from fishing their waters though Federal waters and a few states still allow this fishing. Menhaden are the “street sweepers” of the Atlantic filtering four to six gallons of water of algae per minute.  This algae, if left unchecked, prevents oxygen from proliferating in water which can cause dead zones in water.  (This is bad because nothing will grow or thrive.)

If you must take fish oils, I ask that you find locally sourced, fresh batched, refrigerated sources.  I can’t honestly make a recommendation about one that could be classified as truly sustainable and healthy.

I was once one of those taking handfuls of fish supplements and cod liver oil.  I ate wild caught salmon daily and still my lipid profile went very wonky.  I have since stopped using fish oils and though I do eat oily fish on occasion, I prefer wild caught shellfish or white fish cooked in either butter, ghee, or coconut oil and only every once in awhile.

Refrigerated flax seeds and chia seeds in small amounts can be used to create a lot of the DHA and EPA which creates Omega-3 in the body but even these should be kept to a reasonable amount.  If you are eating plenty of vegetables you should be getting adequate Omega-3.

Wishing you peace and balance,








25 replies
  1. mary
    mary says:

    Well, when my current batch of fish oils (in the fridge!) are gone I’m going to give them a break for a bit and see how I feel. I don’t take handfuls of them and never have – this is interesting stuff and I’m currently open-minded about it all!

  2. Susan
    Susan says:

    I don’t know how you have time to write with your new babies keeping you so busy! I am so happy to hear they will all be together this week! This article is an eye opener that’s for sure. I am happy to say I am not a huge fish oil consumer but thought I was missing out. As always your articles make me think & I do listen. Thanks for continuing to share your valuable knowledge with us all. Glad you are doing well & hope you have lots of help with your busy brood at home. <3 Susan

    • thedetoxdiva
      thedetoxdiva says:

      Thanks Susan for the wonderful thoughts. The babies will be reunited today and we are so happy. Yes, I have TONS of help at home, thankfully! Fish oil is one of those nutritional bugaboos (like many supplements honestly) that can do more harm than help!

  3. David
    David says:

    Hi, Susan.
    Thank you so much for your helpful information. It is very important to know every person. What do you think about ALA VS. EPA, DHA & Sunflower oil.
    Thanks a lot.

    • thedetoxdiva
      thedetoxdiva says:

      I don’t actually think taking ALA vs. EPA is much different. ALA isn’t AS effective supplement wise because it must be converted to EPA and DHA before it is utilizable. EPA and DHA, however, are often supplemented in fish oil and those are most often rancid (as is much of the sunflower oil) because of the high temps by which it is processed, the improper storage, and the long shelf stay.

    • thedetoxdiva
      thedetoxdiva says:

      I actually DO like fermented cod liver oil because it is cold pressed and fermented. It retains all the nutrients such as omega-3 and vitamins A and D. Most people don’t understand the difference so it is one of those supplements I only recommend to those who might understand not to go out and buy a big jar of regular cod liver oil. 🙂

      • ValarieMarie
        ValarieMarie says:

        I’m estrogen dominant, with PCOS and Insulin Resistance and Flax seeds helped lower my estrogen a lot. Also helped with my A1C levels and weight… so….

        • thedetoxdiva
          thedetoxdiva says:

          Ok, and I have, quite awhile ago, thanks to a brilliant anti-aging doctor in Switzerland reversed my opinion on flax seed however, my opinions on fish oils have most assuredly NOT reversed.

  4. Sharon
    Sharon says:

    I had viral meningitis and was left feeling brain damaged. The vitamin store suggested double dosing a good quality of fish oil. After going overboard and feeling I was dying of asthma the hospital couldn’t diagnose asthma. My throat and tounge swelled, then panic. My face felt numb, hands and feet tingle.. I was only taking Tylenol for headache and massive amounts of fish oil. I am now wondering how to detox from this poison.
    Thank you!

  5. Mark
    Mark says:

    Hello Ms. Jaqueline. I had a few questions about this article. I see that you reference various scientific journals and literature in this article such as JAMA, The Cochran Collaboration, and The Food and Crop Institute in New Zealand. Is there any way you could post links to this scientific literature so that I could evaluate it? I find this would be a great opportunity to uncover why many of the national guidelines such as JNC8 or others written by the American College of Cardiology for treating certain cardiovascular diseases/events such as hypertension, stroke, DVT/PE, transient ischemic attack, peripheral artery disease, or coronary artery disease still recommend the use of fish oil even though it has been debunked by valid clinical studies/reviews. Usually they are quick to remove these from the newer guidelines when they are published and change the teaching methods taught in healthcare schools as well as the methods practiced by healthcare professionals.

  6. Lauren
    Lauren says:

    There are 2 main issues with how modern westerners, especially Americans, address nutrition, and cod liver and fish oil are perfect examples of this.
    One, they tend to super-size everything, taking way too much. And two, they take the same supplements, year round, for long term. Fish oil was a seasonal supplement traditionally, used to build strength on the immune system and body. Seasonal eating and supplements elude most people today.

    And the western scientific paradigm breaks everything down into isolated, biochemical components. That’s not a complete picture of how the inherently holistic human body works.

    It also seems like nobody looks to other cultures prior to making blanket statements one way or the other. This applies to many different popular nutrition and diet ideas today. Um, many cultures have thrived on their particular diets and herbs for 1000s of years, so absolutes clearly don’t apply.

    Thanks for this article. Rancid oils are definitely a big problem. Poor quality plagues many supplements on the market today.
    Too many take fish oil on going and do not reassess the body’s needs. A supplement should help heal the body and balance it, thus creating a new baseline from which to evaluate.

    And neutraceuticals are another western approach that has its limits, where whole herbal remedies and supplements may work better in many cases. Isolated compounds are not necessarily more potent or active on the body itself


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