Claire Corlett

Fish Food, Fish Tanks, and More
Is Fish “Brain Food” for Older Adults?

Is Fish “Brain Food” for Older Adults?

“Is Fish “Brain Food”
for Older Adults?” In the landmark Global Burden
of Disease study, they compiled the top 20
causes of death and disability. Number one on the list was
high blood pressure, two and three are smoke. The number four leading cause
of loss of life and health was not eating
enough fruit. Lack of exercise was
number ten, then too much
sodium, then not enough
nuts and seeds, not enough whole grains,
not enough vegetables, and number 18 was not getting enough
long-chain omega-3 fatty acids like EPA and DHA
found in seafood due to their purported protective
effect against heart disease. Even years ago when this
was published however, they 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 recent
meta-analysis, that I profiled previously that appeared to put
the issue to rest. Cardiovascular protection
isn’t the only thing fish and fish oil consumption
was hyped for, though. Omega 3’s have also been
touted to treat depression, but 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all the negative results that went UNPUBLISHED,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 previously
in my video on fish consumption
and suicide. But what about
for the prevention of cognitive decline
or dementia? The available randomized
controlled trials show no benefit for cognitive function for
omega-3 supplementation in studies lasting from six
months to 40 months among healthy
older adults. It may sometimes
even make things worse. Higher current fish
consumption predicted WORSE cognitive
performance and greater PAST fish
consumption in childhood predicted slowed perceptual
speed and reaction time. This may be due to neurotoxic
contaminants in fish, such as mercury. 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 like this, where higher Omega-3
levels were associated with high levels of cognitive
impairment and dementia. More EPA found in the
cognitively impaired and more DHA found
in the demented, presumably because of
pollutants like mercury and PCBs in seafood that
have been related to cognitive impairment
or Alzheimer’s disease. The same cognitive functions
disrupted in adults, like attention, fine-motor function, and
verbal memory, are similar to those
previously reported in children exposed
in the womb. And the adults exposed to mercury
through fish consumption didn’t just have like subtle EEG
brain wave changes or something, but observable deficits in neurobehavioral
performance measures, for example poorer
performance on tests of fine motor speed and dexterity,
and concentration. Some aspects of verbal
learning and memory were also disrupted by
mercury exposure, and the greater the mercury
levels the worse they did. But look, this study was done
downstream of a gold mining operation, 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? In fact, an elite group of
well-educated participants, really well educated— most were corporate
executives like CEOs, all living in Florida, and wealthy enough to
afford so much seafood that at least 43% exceeded
the EPA’s safety limit for mercury. And it had an effect. Excessive seafood intake,
which they defined as like more than three or
four servings per month of fish like tuna or snapper, elevates mercury levels and
causes cognitive dysfunction. Not much-only about a
5% drop in cognitive performance, but a decrement
that no one, let alone a health conscious and achievement-
oriented person, is likely to welcome. It’s worth noting the irony
of the situation. The fact that corporate executives
who choose to over consume seafood for health reasons
instead sustained a DROP in their executive functions
as a result. 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 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.

74 comments on “Is Fish “Brain Food” for Older Adults?

  1. Ah, this is very interesting. I was thinking about this subject the other day. Seems to me that the food industries are just out to make a profit.

  2. what if you avoided large predatory fish that have lots of mercury accumulation from the food chain and ate mostly smaller fish with less mercury? Would there be a benefit between omega 3 and brain function then if you eliminate mercury from the picture?

  3. Every adult I know over the age of 60 is taking fish oil supplements. I try to tell them it's doing them no good and likely harming them. They ignore me and say that their doctors recommend it.

  4. I've been vegan for 5 months now, and never going back because I feel so good without having any animal products inside my body. just wondering how does the fat from fish specifically affect cognitive development? I see the results but I want to understand how the fatty acids from fish affect the brain? informative video 😃

  5. don't buy fish oil it kills fish. You can get all of your omega 3's from hemp seeds,chia seeds, flax oil, also algae

  6. Dr. Crazy has an agenda, don't eat flesh.
    His Granny was dying of heart disease at 65, couldn't walk 10 feet without angina pain.
    Two weeks a vegan and Granny was walking ten miles a day.
    Granny lived for 30 more years, and Dr. Crazy is not a liar.

  7. Well, about the mercury, I guess that's a sea fish problem, but eating fish from aquaculture would solve that point, thus most of what you explained afterwards.

  8. hmmm, I never could stand the taste of salmon and the infamous tuna bake so many loved has never been cooked by me – but to think my beloved shrimp might be my downfall is scary

  9. Have you seen studies re: "Should people with mercury containing dental fillings have them removed? Is there risk of spreading mercury systemically when removing the tooth?"

  10. It's not just the Mercury though…there's all sorts of other junk in fish that's toxic to the human body.

  11. What about in areas or places where fish has been a primary staple? Such as say in Alaska. Are their bodies just not metabolizing all the mercury due to exposure or better fish? For instance what about tuna?

  12. Although modern fish has various levels of contaminants like mercury, PCBs, and dioxin, they also have beneficial omega-3 fatty acids, iodine, and selenium. And yet, there might be more to fish than these nutrients, because some studies have found that people who eat fish gain benefits, such as increased brain volume, that are not matched by taking fish oil supplements [3]. Perhaps this is because fish also contain zinc, selenium, and DMAE, which are not found in fish oil supplements. I currently think that eating fish up to twice a week is probably more helpful than harmful, provided it is of the low-contamination variety. Indeed, every single source on the internet that I’ve encountered that collectively forbids all types of seafood have coincidentally promoted veganism. For example, compare the opinions of the American Heart Association (not vegan) [12] and Harvard School of Public Health (not vegan) [13] with the opinions of PCRM (vegan) [14] and (vegan) [15]. I'll occasionally eat Alaskan salmon, trout, sardines, and arctic char, all of which are low-contamination. Most shellfish are also alright health wise if they are specifically from non-polluted water, but I personally don’t enjoy their flavor. All other types of seafood are discouraged. Sustainability is a major issue regarding seafood, and I trust for addressing this issue.


  13. Great video thank you. Can you tell me if there is any proven mechanisms to reverse mercury/pollutants (with research references) which may have been caused by fish oils? I fear many of us that listened to the wisdom of the time may have already been poisoned!

  14. Risk factor #1 is high blood pressure, and risk factor #11 is too much sodium. What's the disconnect? How much or how little does sodium intake affect blood pressure?

  15. What about flax seeds, are they beneficial and in what way? Also, what is the difference between the different colors like golden vs white vs dark?

  16. Disappointed in the bias in this video. Every other health organization recommends eating two servings per week of low contaminated fish for omega threes (dha). The evidence supports the idea that eating them FAR outweighs the cons of the very small amount of contaminants in these types of fish (Alaskan salmon, sardines, herring, etc). Dr. Greger should mention this at the end of the video, and leave it up to the viewer to decide whether they want to get their dha from fish or supplements.

  17. Do a video on cherries. It will go well with your cherry picking. You were actually pretty good a couple of years ago but sadly you have become so irritating with your pro-vegan mantra that you are rapidly losing respect. Deluded.

  18. I am a Vegan but I have a hard time denying the benefits of fish consumption especially given that Japan and especially Okinawa have the longest lived most cognitively functioning aged population how do you explain this Dr.Greger ??

  19. OF COURSE those wealthy individuals would have cognitive impairment. They were eating large fish like tuna, swordfish and shark, and lots of it I might add. What about the smaller fish? And I didn't see salmon btw…

  20. I love it how he cherry picks studys…every on needs to listen to Dr Jack Kruse. Especially Dr Greger so he dosnt spread his bias

  21. Evidence BIASED medicine by a faux doctor. He has NEVER treated a human…… It's easier to be fooled than to admit you have been fooled. Please take a look at Colin Campbell today…. may you Gregerphiles enjoy similar decay…. OR smarten up. I sincerely wish you the latter.

  22. I feel way better for upping my oyster and sardine intake. Almost like my brain had been dead for years….add omega 3 and wouldn't you know it…better brain function. I wonder if he has read the study where omega 3 is the only lipid to lower heart desease…probably not. I wonder if the fact that the japanese had the best heart health in the world until the U.S. started sending their food over, the reason? A diet rich in seafood and seaweed (omega 3, Iodine, selenium (which is the buffer for mercury accumalation in the brain). But if you live in the states your definetly fucked. your waters have had it. And keep your nuclear war ships out of New Zealand waters, or there will be trouble lol

  23. It's ironic that the next YouTube recommended video is "Doctor Reviews Fish Oil is the Best Food for Brain, Heart, and Joint Health". Why is getting human nutrition guidance so damn confusing? Black is white, up is down, and good is bad. There is no consensus, just polar opposites. Yes, I'm frustrated.

  24. Bill Gates said chicken is healthy. He is also the one who said based on his funded studies people need more fruit. I think you need to include a study of the postiive effects of meats. Argue the other side. Or not cherry pick studies.

  25. Good Day, Uh… what about Molecularly Distilled Omega-3 Fish Oil supplements ? That would be Long-Chain Omega-3 without any heavy metals. I understand that it is way too hard for the elderly to convert Short-Chain Omega-3 from plant sources to the usable Long-Chain Omega-3 format for health needs. Please kindly advise. Thanks!

  26. Wait, didn't you do a lecture recommending that vegans consume omega-3 from flax seeds because of some studies showing cognitive decline in some vegans who were low in omega-3?

  27. What about salmon? As far as I know they have pretty low concentrations of mercury but are also very high in DHA/EPA.
    Keep up the good work! 🙂

  28. Not fish but Essential fatty acids. We can get from all from plants and in much more bio-available form too 🙂
    Marine Phytoplankton, Hemp seeds, flax, chia, and many many more.

  29. Dr. Greger, since I've read your book, I've changed my diet and now, a lot of people tell me, that I might have orthorexia nervosa. That's when you care too much about eating healthfully. What do you think about it?
    It's true that I care a lot about what I am eating and I often chose NOT to eat some things because they are unhealthy. But maybe this can be too much? But on the other hand, why shouldn't I care about my diet? Why is it wrong NOT to chose candy? That doesn't make sense to me.
    Another thing is, that I started to judge other people, when I see them eating unhealthy.. I don't tell them, but I just tell myself: "they're going to get a heart attack" :/

  30. Excuse me can someone please explain me how you measure executive function in an individual. Some of these studies results are purely pulled out of someones ass. I love fish though. Eat it 5x a week and never felt better than I do today.

  31. Hmm, so the REAL culprit is actually MERCURY intoxication, right ?!

    Correlation does not equate to causality, don't be stupid: blaming the fish would be equal to blame veggies when they actually are "treated" with toxic poisons such as glyphosfate.

    I'll keep eating my sardines that are not loaded with mercury, since unfortunelly most of other big fishes are either farmed or/and contaminated.

    Fish oil suplements are also trash most of time since they are contaminated and oxidated; the one doctor Mercola sells is mercury free and fresh, or, just use cold extracted krill oil wich is even better in many aspects.

    I hope this was helpful. Have a nice day.

  32. Sardines don't have those issues. Tried vegan diet but then developed allergies to gluten and high FODMAP foods. Very challenging to get enough protein when you eliminate all those food groups without eating animal proteins.

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  34. At Mor's Nutrition & More we offer multifaceted Nutritional Consultation Services, focused on improving overall healthy lifestyle choices to high performing, high stress individuals including executives, athletes and health challenged individuals.

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  35. Sounds interesting but how can you objectively determine a 5% drop. How as the drop quantified? I'm a little skeptical because of the amount of fish Japanese ad Koreans eat and they're some of smartest people living. "Me thinks" your study is flawed

  36. Question. When taking fish oil such as Cod Liver Oil. Will that have the same negative affect as the sea food intake to cause cognitive disfunction? ?? Please get back to me. Should I throw out my Cod Liver Oil Suppliments ?..

  37. Is there a fish without mercury? As mercury is not inherent in a fish's makeup, but rather a byproduct of environmental pollution wouldn't an easy fix be fish that is farm raised in a controlled facility free of mercury?

  38. Love your channel, but I'm sad to see the harsh bias you got against seafood altogether. You didn't say anything about smaller fish, sardines for example, and how they are extremly low in mercury, and they are very high in B12, DHA and AA fatty acids, selenium, vitamin D, and are completely safe to eat. The fact that you went in on the subject of seafood, but only cared to mention the most high-content mercury-filled fish, and nothing about all the lower-chain seafoods such as shellfish, is disappointing.

  39. If animal products are not good why is that bodybuilders are healthy like dexter jackson, levrone, jay cutler though they eat tons of meat, eggs , fish and chicken

  40. shiiit – wish i didn't have to eat to survive and stay healthy – thunk of the waste of time, much more than waiting in traffic.

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