Health Topics

  1. #
  2. A
  3. B
  4. C
  5. D
  6. E
  7. F
  8. G
  9. H
  10. I
  11. J
  12. K
  13. L
  14. M
  15. N
  16. O
  17. P
  18. Q
  19. R
  20. S
  21. T
  22. U
  23. V
  24. W
  25. X
  26. Y
  27. Z
Browse All Topics

Red Fish, White Fish; Dark Fish, Atrial Fibrillation

The consumption of dark fish, such as salmon, swordfish, bluefish, mackerel, and sardines, may increase one’s risk of atrial fibrillation, an irregular heart beat rhythm associated with stroke, dementia, heart failure, and a shortened lifespan.

May 25, 2012 |
GD Star Rating


Supplementary Info

Sources Cited


Image thanks to Popfossa and marc kjerland.


Another surprising fish story out of Massachusetts last year. Atrial fibrillation… is the most common clinical cardiac arrhythmia, an irregularity of our heart beat rhythm, which can set you up for a stroke, increase your risk of dementia and heart failure, and significantly shorten our lifespan. Previous findings on the effect of diet have been conflicting. Some studies have found alcohol, caffeine and fish consumption to be good in terms of preventing or resolving atrial fibrillation, and other studies have shown them all to be bad.
It’s when this kind of situation arises in nutritional science, you pull out the big guns and put it to the test in one of the bigger better studies, like the famous Framingham Heart Study population like they did here.
 They found no effect either way in general from the consumption of alcohol, caffeine, or fish, but when they looked closer they observed an association between the consumption of dark fish and atrial fibrillation. A 6-fold higher hazard ratio. What they’re talking about is basically salmon, swordfish, bluefish, mackerel, and sardines.
The conclude their findings may suggest a “true adverse effect of dark fis and fish oil on certain subtypes of atrial fibrillation, proposing that “potential toxins such as dioxins and methyl mercury accumulated in certain fish may have a negative effect on cardiac arrhythmia.”

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring watch the above video. This is just an approximation of the audio contributed by Serena.

To help out on the site please email

Dr. Michael Greger

Doctor's Note

See also Boosting Heart Nerve Control for how one can improve heart rhythm function through diet, and there are other videos on alcohol, caffeine and the persistent organic pollutants that build up in the aquatic food chain. The mercury that accumulates in fish can also affect brain function in children and adults, just one of more than a thousand topics I cover.

Also be sure to check out my associated blog posts, Mercury Testing Recommended Before Pregnancy and Eating To Extend Our Lifespan.

  • Michael Greger M.D.

    See also Boosting Heart Nerve Control for how one can improve heart rhythm function through diet, and there are other videos on alcohol, caffeine and the persistent organic pollutants that build up in the aquatic food chain. The mercury that accumulates in fish can also affect brain function in children and adults, just one of more than a thousand topics I cover.

    • HemoDynamic, M.D.

      Great Vid!! Let me tell you why!
      For some reason everytime I tell a patient about a plant based diet (which is probably between 5-10 times per day) why is it that nearly everyone, after I get done telling them about not eating animals/meat, they ask, “Can I still eat fish?”  Then by the sheer inquisitively, perplexed look on my face they respond with, “No?  But it has lots of Omega-3′s”
       I respond, “Sure it does, but if you also like dioxin, DDT and Mercury in your diet and want to act like the Mad Hatter on Alice in Wonderland, then by all means find the fillets and grill the gills.”  This is when they always start to look despondent. (I’m not ‘Fibbin’ either ;-} )
      Why is it people think fish are not animals?  Any insight?

      This video, again, is just one more reason to help keep our patients informed and safe.  If we are going by studies back in the Framingham days as increasing risk of disease what do you think we would find on a study done on todays fish?  Yikes!

    • HemoDynamic, M.D.

      The title could have been, “Red Fish, White Fish; Dark Fish, Afibish.”

      Of course, my humor side got the best of me again. 

  • Vera Springate

    It’s just incredible how toxic everything around has become, and the future is looking even more so, doesn’t it?  Is wild fish from Northern waters (Alaska) any better?  Or is it filled with mercury and Prozac there too?  Are you saying in this video that f.e. halibut is relatively safer to eat than salmon?

    Damage to environment is irreversible as I see it.  And I can’t say I see a lot of healthy looking people around, especially teens and small children, so can’t truly be hopeful.  How do you feel about this, Dr Greger?

    • Toxins

       All fish will contain certain levels of contaminants, even the “cleanest” fish, like Alaskan salmon still contain modest levels of pcb’s and it is recommended children should not consume this fish no more than 3 times a month. Fish are probably the most polluted of the animal products and since we are striving to achieve an optimally healthy diet, fish should be excluded from the diet.

      • Vera Springate

        Thanks very much.  If you were to eat any animal protein twice a week, what would you go for?  Cleanliness is the key of course.

        • Toxins

           I am personally vegan simply because I cannot view any animal product as healthy to eat. They all have their issues and one can achieve excellent health on a whole foods plant based diet without meat. If one is trying to cure themselves of type 2 diabetes for example, the inclusion of meat, even once a week, regresses the healing of this disease.

          if you must have that meaty taste I would say go for mock meats, although even these foods are highly processed, but they are better than the actual meat itself.

        • Coacervate

          Home-raised, free-range egg whites

  • Michel Voss

    Studies are still conflicting: Wu JH, Lemaitre RN, King IB, Song X, Sacks FM, Rimm EB, Heckbert SR, Siscovick DS, Mozaffarian D. Association of plasma phospholipid long-chain ω-3 fatty acids with incident atrial fibrillation in older adults: the cardiovascular health study. Circulation 2012 Mar 6; 125(9):1084-93.
    Source Circulation. 2012 Mar 6;125(9):1084-93.

    • Toxins

       Fish is not the only source of omega 3. An abundance of omega 3 exists in the plant world.

  • Reco Davis

    What about fish oil? I use Norwegian Gold CO2 extracted pills which are IFOS certified. Other than these, I am vegan. …Concerned that the pills might not be the best way to obtain EPA and DHA though, even though it appears they are the cleanest and least oxidized on the market.

  • Gary B

    This is the truth! I weighed 297lbs at the age of 38 was on BP and cholesterol meds. So I decided to lose weight by eating healthier and jogging 3 years ago. I stopped eating red meat and salmon became my meat of choice. I had my first afib event after jogging 4 miles on a hot June 2010 day. It was very scary, I drove myself to the hospital, I converted spontaneously before reaching the hospital. I had a second event in the following October which did send me to the hospital. A battery of tests revealed no clear reason for my Afib. On top of eating salmon 2 – 3 times daily generally in the form of sushi I was taking fish oil as well. They put me on meds to control the afib, despite that, I had my worse event that Nov. I sought to educate myself as the doctors were just treating me. I had lost 50 pounds I was eating what I thought was very healthy and exercising daily. It really stressed me that I was eating better that I had in 15 years So, I scoured the internet. I found one report by an electrophysiologist in New York that showed a relationship between fish consumption and afib development. When I printed the report and brought it to my personal electrophysiologist he had never heard of it and said “Go eat some salmon and see if you go in to afib.” I’m not joking. My Nov event I had consumed a lot of salmon the day before, too much for it to be a coincidence in my mind. I have since completely stopped eating any animal products.
    I am down to a much healthier 186lbs and I have not had an afib event since and I am off all medications.

    • Thea

      Gary B: That’s an awesome story. I’m sorry you had to go through all that, but I love happy endings. Thanks for sharing your story. I expect it will help other people too. Good luck!

    • laura r

      you were very extreme. anything taken to that level causes harm. i eat salmon 2 xs a week, & other fish. the oil pills are too much.