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The Purported Benefits of Eating Fish

In the landmark Global Burden of Disease study, researchers compiled the top 20 causes of death and disability. Number one on the list was high blood pressure, two and three was smoke, and the fourth leading cause of loss of life and health was not eating enough fruit. Lack of exercise was number 10, followed by too much sodium, not enough nuts and seeds, not enough whole grains, and then not enough vegetables. Number 18 on the top 20 list was not getting enough long-chain omega-3 fatty acids like DHA and EPA found in seafood, due to their purported protective effect against heart disease. As I discuss in my video Is Fish “Brain Food” for Older Adults?, even years ago when the study was published, researchers were already questioning the benefits of these fish fats, as more and more randomized controlled trials put them to the test and they failed, culminating in the meta-analysis I profiled in my video Is Fish Oil Just Snake Oil? that appeared to put the issue to rest.

Consumption of fish and fish oil wasn’t only hyped for cardiovascular protection, though. Omega-3s have also been touted to treat depression. However, after taking into account all the negative results that went unpublished, there appears to be no benefit for major depression or for preventing suicide, as I explored in my video Fish Consumption and Suicide.

What about omega-3s for the prevention of cognitive decline or dementia? The available randomized controlled trials show no benefit for cognitive function with omega-3 supplementation in studies lasting from 6 to 40 months among healthy older adults.

It may sometimes even make things worse. “Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time.” This may be due to neurotoxic contaminants, such as mercury, in seafood. We’ve known that the developing brain is particularly sensitive to the damaging effects of mercury, but maybe the aging brain is as well.

This would explain results that have shown higher omega-3 levels to be associated with high levels of cognitive impairment and dementia. More EPA (eicosapentanoic acid) was found in the cognitively impaired, and more DHA (docosahexanoic acid) was found in the demented, presumably because of pollutants like mercury and polychlorinated biphenyls (PCBs) in seafood that have been related to cognitive impairment and Alzheimer’s disease.

The same cognitive “functions disrupted in adults, namely attention, fine-motor function and verbal memory, are similar to some of those previously reported in children with prenatal exposures,” that is, exposed in the womb. And, the adults exposed to mercury through fish consumption didn’t have only subtle EEG brain wave changes, but “observable deficits in neurobehavioral performance measures,” such as poorer performance on tests of fine motor speed and dexterity, as well as concentration, for example. “Some aspects of verbal learning and memory were also disrupted by mercury exposure,” and the greater the mercury levels, the worse they did.

That study, however, was done downstream of a gold mining operation, which uses a process that uses lots of mercury. Other such studies were done on people eating fish next to chemical plants or toxic spills, or eating whale meat. What about a more mainstream population? An “elite group of well-educated participants”—most were corporate executives like CEOs and CFOs––all living in Florida and wealthy enough to afford so much seafood that at least 43 percent exceeded the U.S. Environmental Protection Agency’s safety limit for mercury were studied. Researchers found that excessive seafood intake, which they defined as more than three to four servings per month of large-mouth fish like tuna, snapper, and bass, elevates mercury levels and causes cognitive dysfunction, resulting in about a 5 percent drop in cognitive performance. This may not seem like much, but it’s “a decrement that no one, let alone a health-conscious and achievement-oriented person, is likely to welcome.”

“It is worth noting the irony in the situation; that is, the fact that corporate executives who chose to overconsume seafood for health reasons sustained a drop in their executive functions. Yet, if a 4.8% drop in executive function due to excessive seafood intake occurs in highly functioning, healthy adults with ample cognitive reserve, the major concern for further study is whether similar [mercury] level elevations in individuals already suffering from cognitive decline might result in substantially greater declines,” particularly with cognitive decline, dementia, and seafood consumption on the rise.


Fruit deficiency is the number-one dietary risk factor? For more, see Inhibiting Platelet Aggregation with Berries.

But what about th Inuit? See Omega-3s and the Eskimo Fish Tale.

For more on the shift of the evidence on fish and heart disease, see my Is Fish Oil Just Snake Oil? video.

The greatest danger of mercury exposure may be for children, as I discuss in Mercury vs. Omega-3s for Brain Development and How Long to Detox from Fish Before Pregnancy?.

Other videos on the effect of fish contaminants and health among adults include Fish and Diabetes and Fish Consumption and Suicide.

Mercury is not the only neurotoxic contaminant of seafood, though. See Diet and Amyotrophic Lateral Sclerosis (ALS) and ALS (Lou Gehrig’s Disease): Fishing for Answers.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Discuss

Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.


86 responses to “The Purported Benefits of Eating Fish

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  1. From the last paragraph: “the fact that corporate executives who chose to overconsume seafood”

    and

    “due to excessive seafood intake”

    What was considered “overconsume” and “excessive”? Once a day, three times a day….?

    1. Never mind, I found it. Hadn’t read it carefully enuf. From the paragraph above the last:

      ” Researchers found that excessive seafood intake, which they defined as more than three to four servings per month of large-mouth fish like tuna, snapper, and bass,”

      So they’re talking about large-mouth fish then? Not my once or twice a week sardines or wild-caught salmon?

        1. Thanks, Barb. I figured an NF link couldn’t exactly be “pro” fish, and it wasn’t. :-(

          The comments below the link were interesting. Back in 2015 (when Thea was still around) posters could call themselves “Guest,” and also vote “up” for themselves. Such egos. :-) They also swerved off into other topics, much like today’s bunch. For instance, they got talking about skin cancer and soap and stuff.

          I think Lonie said he eats herring once in a while. Of course, he takes in a special boatload of daily concoctions, so maybe this offsets the effects of that nasty nasty fish. As I’ve no health issues (knock on wood), I’ll just continue to do what I’m doing. (This does not include buying fish from the supermarket bins. Am usually suspicious about its origins, etc.

    2. As the article stated, “Environmental Protection Agency’s safety limit for mercury were studied. Researchers found that excessive seafood intake, which they defined as more than three to four servings per month of large-mouth fish” So more than that would be consider excessive.

  2. I am a little confused, because this article seems to imply that omega-3s don’t actually have any health benefits at all, but in other videos you have recommended supplementation from non-fish sources (e.g. https://nutritionfacts.org/video/should-we-take-dha-supplements-to-boost-brain-function/).

    I’m guessing the answer is that omega-3s are themselves beneficial but not when they’re delivered along side heavy metals and neurotoxins, but it isn’t clear whether that is the case or if the video is simply outdated now.

    1. I agree on both counts. While Dr. Greger has a whole body of good videos on omega 3s, this article occasionally discusses omega 3 consumption and fish consumption in a way that seems to conflate omega 3s with the deficits of fish. For example, “What about omega-3s for the prevention of cognitive decline or dementia? The available randomized controlled trials show no benefit for cognitive function with omega-3 supplementation in studies lasting from 6 to 40 months among healthy older adults.” I believe this only applies to fish oils.

      And your conclusion is right on. Omega 3s are still essential. Further, omega 3s are often deficient in vegetarians, especially vegans. And with regard to supplementation, this is one area in which Dr. Greger recommends supplementation (algal or fungal EPA/DHA).

      1. Stephen, I read the comments today and a couple of things come to mind. One is that fish (yes salmon), carry a parasite load – so do other animals, but pets and livestock are de-wormed as part of regular health care. Having seen enough parasites in enough fish to last me a lifetime, I will decline the fish course. Looking to algae supplements, well, these are a ridiculous price and out of the question for ,any. The other thing is that yes, I agree, trials with algae sources would be good (maybe Dr Greger mentioned them already), and those trials with vegan/wfpb people too.

        The reason why I mention this is because in a past discussion Mr Fumblefingers came up with a study that showed vegans had greater ability to convert omega 3 UNTIL they were given supplements! This makes me wonder if interfering by taking supplements is a good thing.

        1. Barb

          Jack Norris (as usual) offers an excellent summary of the evidence. Go to veganhealth.org and check out the articles on omega 3s.

    2. Yes, I had the same question, I recall a video I saw years ago in which Dr. Greger addressed the apparent anomaly that vegetarians and vegans seemed to have the same rates of heart disease as omnivores, by arguing that vegans could address that by supplementing with omega-3s.

    3. I might have posted this, but my brother is in surgery right now and I think I messed up.

      Pretty sure Dr Ornish did a video on whether Omega 3’s actually have value or not and the jury is out.

      I can’t remember even if it was Ornish or Barnard, but it was YouTube and it was a discussion on the topic.

      1. They had problems during my brothers surgery. Simple emergency surgery became a long night and the one thing which fascinated me is that I fell asleep for 3 hours during it.

        Anyway, just sad tonight, but happy I slept. I wonder why I can’t sleep when I try to sleep, but I fall asleep when I try to stay awake.

        1. Well, his surgery was 5 hours and he will be in the hospital until Tuesday and his recovery will be a month, but both of my brothers and my dog are still alive.

  3. That was a powerful blog entry. I ate a lot of tuna fish as a young person. That was my favorite bring for lunch sandwich in grade school.

    I know that the executive function of my brain is injured and this will cause me to look for chemicals. I am so chemically sensitive and always have been.

    I have had so many things to learn that I haven’t tried to heal my executive function yet. I will have Siri add it to my list.

    Siri used to be this frustrating thing, but yesterday, I used her to load my calendar, to text my relatives, to make notes for me and to set an alarm for me to wake up by and she chose a very good one and I didn’t have to open any apps or text boxes. Alexa might be better because Siri can get me to the latest video on this site, but couldn’t scroll the comments for me. I watch the pause/resume commercial on Alexa and I didn’t try that with the videos from here yet.

    1. It should be noted that the people who performed best in the tests had mercury levels higher than the lowest group. The authors concluded that the brain benefits of the (DHA/EPA) omega 3s from fish outweighs the risks posed by “intermediate” levels of mercury. As a vegan I do not eat fish but I think it important to have the facts stated clearly – DHA/EPA is important to cognitive functioning. Getting those omega 3s from less contaminated fish would then seem to be brain beneficial. One can, as I do, rely on an algal supplement but there is still an issue not yet addressed by Dr. Greger or anyone else I am aware of, namely, there is evidence from rodent studies that the free fatty acid form of the omega 3s found in typical supplements do not in significant amounts cross the blood brain barrier. They do, however, easily accumulate in other body tissues. On the other hand, lipid forms do easily cross the barrier. It seems to me reasonable to think that typical DHA/EPA supplements are not really supporting brain health. That’s quite a downer, if true.

      1. Perhaps I should clarify what I meant by “lipid form”. I meant “bound to e.g lysophosphatidylcholine”.

        Here’s one study:
        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596017/
        Dietary docosahexaenoic acid (DHA) as lysophosphatidylcholine, but not as free acid, enriches brain DHA and improves memory in adult mice

        Here is a quote from another one:
        http://www.jlr.org/content/early/2018/12/10/jlr.M090464
        Dietary lysophosphatidylcholine-EPA enriches both EPA and DHA in the brain: Potential treatment for depression
        “However, the brain contains negligible amounts of EPA, and dietary supplements fail to increase it appreciably. We tested the hypothesis that this failure is due to absorption of EPA as triacylglycerol, whereas the transporter at blood-brain barrier requires EPA as lysophosphatidylcholine (LPC).”

        I just recently stumbled across this topic and have a ways to go before I feel I am on top of it. But it does raise the question…

        1. And for those who do not want to read the studies, here’s a key quote from the first one cited:

          “Docosahexaenoic acid (DHA) is uniquely concentrated in the brain, and is essential for its function, but must be mostly acquired from diet. Most of the current supplements of DHA, including fish oil and krill oil, do not significantly increase brain DHA, because they are hydrolyzed to free DHA and are absorbed as triacylglycerol, whereas the transporter at blood brain barrier is specific for phospholipid form of DHA. Here we show that oral administration of DHA to normal adult mice as lysophosphatidylcholine (LPC) (40 mg DHA/kg) for 30 days increased DHA content of the brain by >2-fold.”

          1. How would you get enough Omega-3 as a vegan then if not through the algae Omega-3 supplement? Do you get enough from 2tbps flaxseed if you don’t want to consume fish?

            1. I take an algal supplement as per the recommendation of Dr. Greger and Dr.
              Fuhrman. I am skeptical of relying on conversion from ALA from only eating flax, walnuts etc to get enough. However, as mentioned, I am now wondering about the effectiveness of the free fatty acid forms for brain health.
              Hopefully that will prove to be a non-issue.

            2. >>> Do you get enough from 2tbps flaxseed if you don’t want to consume fish The amount of EPA derived from the ALA in flaxseed, walnuts etc is highly variable (gender, individual genetics), so 2 TBL ground flaxseed is no guarantee.

              1. I understood that the conversion rate is extremely poor and that the risk of damage from cyanide is higher than the chance of benefit.

                1. Right, the conversion rate is quite, even shockingly, poor. Gender and specific polymorphisms are key variables. I recall from somewhere that some people of European ancestry tend to be especially poor converters. This underscores the importance of considering individual variation, although unfortunately this can be difficult (to say the least) to do.

                  The best article I know on this topic is
                  https://lpi.oregonstate.edu/mic/other-nutrients/essential-fatty-acids#metabolism-bioavailability

                  “The capacity to generate DHA from ALA is higher in women than men. Studies of ALA metabolism in healthy young men indicate that approximately 8% of dietary ALA is converted to EPA and 0-4% is converted to DHA (6). In healthy young women, approximately 21% of dietary ALA is converted to EPA and 9% is converted to DHA (7). The better conversion efficiency of young women compared to men appears to be related to the effects of estrogen (8, 9). Although ALA is considered the essential omega-3 fatty acid because it cannot be synthesized by humans, evidence that human conversion of EPA and, particularly, DHA is relatively inefficient suggests that EPA and DHA may be considered conditionally essential nutrients.”

                2. Gillian23,
                  Cyanide in flax does not seem to be a real issue, at least for reasonable amounts (1 -3 TB/dL).

                  https://www.nutritionletter.tufts.edu/issues/7_8/ask-experts/Are-Cyanide-Levels-in-Flaxseed-Safe_1157-1.html

                  “Q: I recently read that flaxseed contains cyanide. I have been consuming two to three tablespoons of ground flaxseed daily for several years. Should I be concerned? Does this quantity of flaxseed provide a clinically significant amount of cyanide?
                  A: Lynne M. Ausman, DSc, RD, director of the Biochemical and Molecular Nutrition Program at Tufts’ HNRCA Cardiovascular Nutrition Laboratory, says you have nothing to worry about. Many foods, including not only flax but cashews, almonds, some beans and other plant products, naturally contain very small amounts of cyanide compounds. You’re more likely to ingest these trace amounts of cyanide when such foods are consumed raw, as heat breaks down the compounds. Even when flaxseed is eaten raw, the body has a natural capacity to break down a certain amount of these cyanide compounds. A 1994 study found that, in healthy individuals, daily consumption of as much as 60 grams of raw flaxseed—more than eight tablespoons—was safe.”

            3. Please check out these NFO videos including Dr.Greger’s recommendations on supplements:
              https://nutritionfacts.org/video/should-we-take-epa-and-dha-omega-3-for-our-heart/
              https://nutritionfacts.org/video/should-vegans-take-dha-to-preserve-brain-function/ and
              https://nutritionfacts.org/2011/09/12/dr-gregers-2011-optimum-nutrition-recommendations/ which will answer your question regarding if just the flaxseed is adequate (It appears it is not.)

          2. 言語学者 (gengo-gakusha), It sounds like some company is getting ready to sell a new supplement … a new form of DHA that will cross the blood-brain barrier ;-)

            The “research” studies always come first !

            1. Yes, that’s not unlikely. There is already one product I know of that sells DHA in the phospholipid form naturally found in salmon. Somehow I think the facts of DHA metabolism have to be ‘smarter’ than those rodent studies indicate, if only because the brain is so dependent on it.

          3. Thank you for your informative post. it is important that people who choose to exclude food groups from their diet on the basis of the SCIENCE, do actually address the science, not merely some handy predigested snippets with a confirmation bias.

            It may be that the only way to approach the subject of what you eat is from a normative ethical standpoint and not a scientific one….. as in the science tending in the end always to favour moderation across all the food groups and the elimination of certain agreed toxins with no alleged nutritional benefits that cannot be obtained from other good stuffs, like alcohol.

            1. ” the science tending in the end always to favour moderation across all the food groups ‘

              Could you point us to the science that you think shows this?

              The US Dietary Guidelines seem to be the conventional mainstream statement of the latest science and they identify 3 healthful eating patterns, one of which includes is vegetarian and even includes a ‘vegan’ option. This seems to directly contradict your belief.
              https://health.gov/dietaryguidelines/2015/guidelines/appendix-5/

              As for ‘moderation’, I seem to recall Dr Greger doing a video on this very common belief
              https://nutritionfacts.org/video/everything-in-moderation-even-heart-disease/

    2. Check out Anthony Williams website and books, he suggests celery juice to help heal, and there are ways for you to detox from heavy metals.

  4. Still with your blog post and all other posts about seafood have never shown anything bad from eating fish except that they are contaminated with foreign substances to their bodies. The conclusion is that mercury is bad for you and the fish. Hypothetically speaking, if someone ate a fish 100% free from contaminants, would there still be anything wrong with seafood? That’s the real question.

    1. Let’s see, how about the saturated fat and cholesterol that cause cardiovascular disease, our leading killer. The mercury, PCB’s and dioxins are a “bonus”.

  5. What about all the studies that show benefit?

    Fish oil reduces inflammation – https://www.ncbi.nlm.nih.gov/pubmed/25149823

    Eating Fish May Be Associated With a Reduced Risk of MS | Neurology Reviews

    https://www.mdedge.com/neurologyreviews/article/164000/multiple-sclerosis/eating-fish-may-be-associated-reduced-risk-ms?utm_source=News_Power_eNL_042318_F&utm_medium=email&utm_content=Trending:%20News%20from%20ACP,%20AAN%20%20%7C%20Zip%20code%20&%20health%20%7C%20&%20More

    Fish oil may help the heart beat mental stress — ScienceDaily
    https://www.sciencedaily.com/releases/2013/05/130522111951.htm

    fish oil can improve the quality of LDL particles while reducing triglycerides – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689018/

    1. yes, I’d agree with many of the comments here. This blog doesn’t really make FISH out to be bad. Just CONTAMINATED fish.

      Well, of course mercury will be bad for you. But fish? I love Dr. Greger, but the headline is deceptive.

  6. Fish don’t ‘make’ Omega 3s. They get it from eating things that eat algae species which do create those lipids. Those algae can be grown by the vatful in clean water without the pollutants.
    DHA capsules from this process are at Wally-world, aka Walmart. Could there be tests of Omega 3 value using this clean product?

    1. Perhaps as the lipids go up the food chain they get packaged better by each species they become a part of? Reductionism vs holism.

  7. It seems like one couldn’t interpret the data correctly given how the studies were reported. It says,

    “participants received gel capsules containing either omega-3 PUFA (the intervention) or olive or sunflower oil (placebo) for six or 24 months. In one study, participants received margarine spread for 40 months; the margarine for the intervention group contained omega-3 PUFA.”

    Unless I’m reading the study wrong, none of this describes the source of the omega-3 PUFA and in the example of the margarine spread, my guess is that they would have used canola oil for the omega-3 PUFA (since canola based margarines are regularly sold for the purpose of adding omega 3 to the diet). Most canola oil is from Round Up treated plants, further complicating the results. So I don’t see how anything of value regarding fish consumption (or for that matter, omega 3) can be interpreted from this study. And if you believe that Omega 3 is not useful (as this study suggests), why would you recommend regularly consuming flax/chia? By the way, I suspect that both flax and chia suppress my thyroid function, so I try to get omega 3 from walnuts and wild salmon (because in my experience, omega 3’s help my vision problems).

  8. We should note that consuming fish in normal quantities may not have an impact on health and longevity. Four of the five Blue Zones consume fish in normal quantities—from once daily to a few times a month. They also consume small quantities of pork a few times a month.

    We can’t say that those levels of fish and pork consumption enhance their health, but it doesn’t seem to have a negative impact on their health.

  9. Dr G I would love it if you could comment on the respected longevity researcher Valter Longo’s claim that eating fish helps extend health and life expectancy.

      1. “… with generous amounts of olive oil (3 tablespoons per day).”
        – – – – –

        Uh-uh, never happening! I’m more 3 drizzles a day (Ezekiel toast) — which measures to less than 1/2 teaspoon.

    1. Yes I have not heard of any studies or tests that show when people are difficient in Omega 3 but I have heard people consuming too much Omega 6 which unbalances the Omegas.

  10. I did research at the NIH Library in Bethesda, MD and found the single greatest source of mercury in people’s bodies is from their silver mercury amalgam dental fillings. Mercury vapor is released from the fillings and inhaled into the lungs where it gets into the blood stream and to the brain. Europe has banned the use of mercury amalgam dental fillings in pregnant women and children. Some countries totally banned mercury amalgam fillings.

    1. Yes it is a worry but apparently mercury is only a problem when heated. I have many fillings thanks to my caring parents who thought they were doing the right thing by taking me to the overzealous dentist. Now my teeth are decaying under the fillings and have no idea how it is harming me, I cannot afford to get the mercury taken out and apparently it is very dangerous to unless you have a very experienced dentist who is willing to do it too. So I have to wait until they fall out. In the meantime clove oil is my new best friend for the pain I get sometimes.

      1. In the same boat. Best bet is probably to just have ceramic fillings put in as the old mercury stuff needs replacing?

        I’ve had a dentist complain…”well what about us?”…since they are exposed to mercury all the time. What I didn’t say…”well you dummies put the stuff in…so take it out.” If the patient is harmed and the dentist is harmed…what’s left of your brain???

        https://www.newscientist.com/article/2191814-we-may-finally-know-what-causes-alzheimers-and-how-to-stop-it/

        “This is the first report showing P. gingivalis DNA in human brains, and the associated gingipains, co-lococalising with plaques,” says Sim Singhrao, of the University of Central Lancashire, UK. Her team previously found that P. gingivalis actively invades the brains of mice with gum infections. She adds that the new study is also the first to show that gingipains slice up tau protein in ways that could allow it to kill neurons, causing dementia.

        The bacteria and its enzymes were found at higher levels in those who had experienced worse cognitive decline, and had more amyloid and tau accumulations. The team also found the bacteria in the spinal fluid of living people with Alzheimer’s, suggesting that this technique may provide a long-sought after method of diagnosing the disease.

        When the team gave P. gingivalis gum disease to mice, it led to brain infection, amyloid production, tangles of tau protein, and neural damage in the regions and nerves normally affected by Alzheimer’s.”

        Solution? Oral probiotics replace the bad oral bacteria with better bacteria?

        ….

        And if gum disease doesn’t dumb you down…there’s the herpes virus…associated with Alzheimers.

        Solution? 500 to 1G l-lysine per day inhibits the herpes virus?

  11. It’s a tricky issue. Probably better not to have such fillings in the first although the alternatives are more expensive and less durable. For those of us with them though, Wikipedia comments:

    ‘The American College of Medical Toxicology and the American Academy of Clinical Toxicology say that research confirms that mercury from amalgams does not cause illness because the amount of mercury that they release is not enough to cause a health problem.[36] In response to some people wanting their existing amalgam removed for fear of mercury poisoning, these societies advise that the removal of fillings is likely to cause a greater exposure to mercury than leaving the fillings in place.[36] These societies warn that removal of amalgam fillings, in addition to being unnecessary health care and likely to cause more mercury exposure than leaving them in place, is also expensive.[36]

    Far more mercury is released when amalgam fillings are removed than over their entire lifetime if left undisturbed. This led to some dentists who advocate removal of amalgam fillings (who may describe themselves as “holistic dentists”) to develop special techniques to counter this, such as wearing breathing apparatus, using high-volume aspiration, and performing the procedure as quickly as possible. The impact of such techniques on the dose of mercury received during filling removal is unknown, and the techniques have been criticized as merely advertising gimmicks which enable such dentists to charge far more than a normal dentist would for the same procedure. Sources of mercury from the diet, and the potential harm of the composite resins (which mimic female sex hormones)[citation needed] to replace the purportedly harmful amalgam fillings, are also ignored by these dentists.

    Consumer Reports has warned its readers on several occasions that, “if a dentist wants to remove your fillings because they contain mercury, watch your wallet.”[7][69][70]’
    https://en.wikipedia.org/wiki/Dental_amalgam_controversy

    1. Check out iaomt.org. There are studies for measuring amalgam vapours during removal of amalgams as well as chewing/ brushing showing we release Mercury vapour daily. Multiply that by the number of days you live with those amalgams. More is released during removal but with the use of high volume suction(which all dentists use), ionizer that traps the Mercury vapour, the large vacuum/ air filter positioned near the mouth with a 3 stage filter system, rubber dam and using the “nasal hood” nose mask to supply 100% oxygen, the levels of the Mercury vapour are not inhaled by the patient or staff. Measurements taken around the operatory show the vapour levels are highest near the large vacuum because the vacuum draws in the vapour. The levels near the patient, dentist and assistant’s face are near zero and the special filter masks are not required. The patient can’t breathe in or ingest the amalgam because of the rubber dam and nose piece.
      Holistic dentists don’t charge extra for removal of amalgams. Yes, the alternative materials/ techniques are more expensive but longevity can be equal to amalgam, even with composites:
      https://iaomt.org/for-patients/alternatives-mercury-amalgam-fillings/
      There are composites that are made without bisphenol A, bisGMA and TEGMA eliminating estrogenic or carcinogenic effects. Full Zirconia crowns or inlays/onlays (and now Zirconia implants) eliminate those “toxic” components, high tensile strength and are metal free.
      Amalgam is a cheap material and not a technique sensitive procedure. They are not bonded to enamel or dentin and when they fail, the morbidity of the tooth damage is great. Composites can be repaired by bonding to them. Can’t bond to amalgam.

      1. Pat,

        Can’t agree with you more as we have been sending folks to biological dentists for >35 years.

        Some of the key aspects of “safe” removal also involve the use of oral DMSA pre and post procedure as the ingestion/inhalation is never 100% and why not start decreasing the overall body burden ?

        Too bad the price has skyrocketed for what was once an over the counter supplement, now a pricy prescription. You can decrease the cost by going to a compounding pharmacy, while they are still allowed in commerce.

        Dr. Alan Kadish moderator for Dr. Greger http://www.Centerofhealth.com

  12. We live in the Midwest and my husband fishes at Lake Okoboji and in some of the rivers, streams and small lakes in the area. The fish we consume is walleye, pike, bluegills, perch and occasionally trout. Do these fish pose the same risk as the others you talked about in the article?

  13. This is confusing for me as I remember a video you did about vegans taking algae oil pills for the DHA and EPA because it proved beneficial. I know this is talking about fish but in this post you’re making it sound like even taking the algae oil supplements is pointless because lack of benefits from the omega 3s. Please clarify

  14. I want to thank you for the detail in this blog. It helped me internally to have a sense of things, which may have caused the brain problems. I have a list of things and I love adding things to the list and searching for things to heal my brain.

    For topics, I have been wondering if there are things for healing specific areas of the brain.

    I have been looking at damage to the hippocampus and amygdala. They are being looked at for Alzheimer’s and PTSD from trauma.

    https://reliawire.com/hippocampus-atrophy-alzheimers/

    https://www.nicabm.com/ptsd-the-hippocampus-and-the-amygdala-how-trauma-changes-the-brain/

    I have also been looking up how to strengthen the Blood-Brain Barrier.

    I found things, but I am just putting it up as a topic, which I would love.

  15. I spent the day watching videos about things like beets versus beet juice.

    I ended up buying grape juice because I can’t find organic grapes anywhere.

    I know Dr Greger said to ear conventional versus nothing and to not do juices, but organic grape juice versus conventional grapes became a ping pong match in my brain.

    I also end up eating the air dried bag of beets rather than do beet prep work.

    Juicing breaks down the fiber but does dehydration wreck anything?

    I ended up also having a beet bar today puréed beets with almond butter and cacao, I think.

    Did I just end up in fast food?

    Does the grape juice have bad stuff like bottled carrot juice?

    The enzymes would be gone, but the study said grape juice so I go back to food cooking methods and put pasteurization on the list with a question mark.

  16. Sorry, I am rambling again. Trying to figure everything out.

    I am going to succeed at this.

    I am going to heal my brain, even if it requires brain plasticity to get everything back.

    I am doing the blueberries and grapes and beets and arugula and kale and flaxseed and nuts and avocado and I bought saffron and I will get the essential oils to diffuse and I started using the TMS setting on my Micropulse ICES and it is so soothing. I slept 5 or 6 hours last night. Better.

  17. I am drinking tea and that is another thing which confuses me because I love hibiscus but it is the one type which might increase aluminum, so I started drinking the stupid Fiji water again. Shoot. I shouldn’t drink hibiscus right now. I wish I could just make it with Fiji water.

    1. Could I make the tea with Fiji water? It binds with aluminum to get it out of my system, can it bind with it ahead of time and keep it out of my system altogether, like DMannose with ecoli?

      Does aluminum like the silica better than it likes being in my brain?

      1. Second night with a 1/2 hour MicroPulse TMS session, second night I fell asleep around midnight and slept until my dog woke me up around 6 in the morning.

        If this keeps up, I am going to be contacting the person who invented it and thanking him again.

          1. Hi Bob,

            I took melatonin 2 years ago, but it backfired.

            Your body eventually stops making it.

            Anyway, I sleep like a baby all through the night now. I have evidence that I didn’t even shift position once last night and only woke up when my dog woke me up.

              1. I am still falling asleep close to midnight but after decades of falling asleep at 4 in the morning, I will celebrate that.

                The only problem is that my brother comes home from the hospital tomorrow and it can help him with wound healing, pain and sleep and if he would try it, I would part with it.

                I lent it to my cousin for 4 months because of his pain but he didn’t even try it.

                I am only going to lend it if he will try it, but my sister-in-law didn’t try it when she tore her meniscus either.

  18. Is it the Omega 3 or the fish oil that is the problem? I have been supplementing with chia oil capsule as I am eating a plantbased diet. Is this worth doing? Are there benefits to taking these Omega 3 capsules?

    1. Anita,
      >>I have been supplementing with chia oil capsule as I am eating a plantbased diet. Is this worth doing? Are there benefits to taking these Omega 3 capsules?
      Depends on the specifics of your diet. Many WFPB diets do not supply sufficient omega 3 fatty acids, whether the essential fatty acid ALA, or EPA/DHA (what is in fish). The latter two are not considered essential by most since in principle ALA can be converted to EPA and from there to DHA (both of which are required). However, conversion of ALA to EPA is limited, in some severely and EPA/DHA is considered by some to be “conditionally essential”. It is for this reason that Dr. Greger and Dr. Fuhrman recommend supplementation, but others disagree. I opt to be on the safe side and take an algae-based supplement per Dr. Greger’s recommendation. Algal DHA/EPA supplements have the advantage that the algae is grown in sterile vats and so should not be contaminated with mercury, dioxin, PBCs, etc.
      Regarding the omega 3 ALA: it is important to get sufficient amounts as it is essential. But why not just eat chia seeds or ground flax seed to get the essential ALA fatty acid? (Walnuts are also high in ALA.) The oil is subject to, but the seed form is protected from, rancidity. Note that flax seeds have to be ground to be digestible. Chia seeds are best soaked for digestibility but do not have to be ground. A typical amount of ground flax seed is 1 TBL/d (again see Dr. Greger’s recommendation). I keep my whole and ground flax seeds in the freezer (I grind them with a small coffee grinder).
      >>>Is it the Omega 3 or the fish oil that is the problem?
      I did not understand the question because the video was about the risks of eating fish high in mercury, which is dangerous. On the other hand, those with higher intake of DHA/EPA and not too much mercury from fish-eating performed better on various cognitive tests. This suggests that the DHA/EPA is important for long term cognitive health but eating oily fish high in mercury is risky. Hence the recommendation to supplement with an algae-based form by Dr. Greger.

      1. I do supplement with chia and ground flax in addition to the chia oil capsules. I live in Mexico so finding things like your algae is not easy. Chia on the other hand is pretty inexpensive. From reading your response I am guessing I don’t need the chia oil capsule which come from the US and are pretty costly. Thank you for you response.

      2. “I opt to be on the safe side and take an algae-based supplement per Dr.
        Greger’s recommendation.”

        May I ask what brand supplement you use?
        Thanks.

        1. Sure. I’ve moved around from Ovega 3 and Swanson’s brand to most recently Deva Vega Omega 3 DHA-EPA. I gave up on the first two because of the carrageenan, an unnecessary and possibly inflammatory additive. I like the Deva brand ok although it does have a bit of a hard to describe taste (I’d say “fishy” but there’s no fish in it). I think the other brands have thicker capsules and additives to mask any taste. I’ve also used Dr.
          Fuhrman’s brand, which I think is superior in quality (comes in a glass bottle and is refrigerated until shipping) but it’s kind of pricey and I like to take a higher dose than he and Dr. Greger recommend. If price were no object, I’d probably use Dr. Fuhrman’s.

  19. I agree with what others have posted about the confusion regarding supplementation — especially what Stephen Billig says: “While Dr. Greger has a whole body of good videos on omega 3s, this article occasionally discusses omega 3 consumption and fish consumption in a way that seems to conflate omega 3s with the deficits of fish” (along with the rest of his post).

    I went back and watched Dr. Gregor’s earlier video too (https://nutritionfacts.org/video/should-vegans-take-dha-to-preserve-brain-function/) just to confirm that my memory was correct, and several of the points he makes there directly contradict the ideas in this blog post. In fact it was specifically that video that led me to start taking a DHA/EPA supplement, though I already consume plenty of the short-chain, plant-based FAs.

    Not sure where the evidence will ultimately lead, but those looking for a good supplement might wish to try the one NuIQue offers — it’s vegan and seems to be of high quality. And it’s one of the few that includes the recommended levels of both DHA and EPA. I began taking it after watching Dr. Gregor’s video recommending that vegans in particular should supplement.

    I would greatly appreciate clarifying commentary from someone on Dr. Gregor’s team.

    1. Hello Marion,

      I believe both yourself and Stephen are on the right track. In general, the research demonstrating negative outcomes in those with higher omega 3 intake are due to the confounding negative effects of fish consumption. The article may be worded in a way to cause confusion, but that is not the intent. There is decent evidence that supplementation with DHA can help preserve brain function as you would have seen in the other video you linked.

      I hope this clears up the confusion,

      Matt, Health Support

  20. Why would you ever ingest something without any evidence that is either safe or effective? For all you know, it could be increasing your risk of premature death. That is what science is for. At this point, we’ve never seen anything better than what mother nature has provided: whole plant food. Wouldn’t it make more sense to just eat that until someone actually proves that you’re helping and not harming yourself? From a pure logic perspective: think back to the studies testing supplementation of lycopene and beta carotene….both anti-inflammatory and both shown to reduce cancer risk. Put it in a pill, give it to humans and…BINGO…HIGHER rates of cancer in those taking the supplement. Yes, that’s right, they are WORSE off taking the supposedly “anti cancer” supplement. We see this across the board with supplements.

    Dr. Ben

    1. Well the major concern is contamination. It is incredibly common for fish oil supplements to contain harmful contents such as mercury, dioxins, pcbs, etc. The best way to avoid this is to take an algae-based DHA supplement, which you can get in liquid or pill form.

      I hope this helps,

      Matt, Health Support

  21. Hello,

    With regards to mercury contents in seafood, are there studies with freshwater fish? Would like to know whether the the contents would be similar?

    I come from a country which is landlocked and mainly freshwater fish is consumed and I haven’t come across articles that would specify.

    Thanks

    1. Hello Anna,

      Funnily enough, freshwater fish actually contains higher levels of mercury than saltwater fish; however, freshwater fish contain less of the other contaminants such as dioxins. Ideally, we should opt for algae-based DHA supplements which are free from contaminants if omega 3s are the concerns.

      I hope this helps,

      Matt, Health Support

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