No effects of omega‑3 supplements on Alzheimer’s symptoms

The L.A. Times reports today the neg­a­tive results of the lat­est ran­dom­ized tri­al test­ing the effects of DHA sup­ple­ments on Alzheimer’s symp­toms (DHA is an omega‑3 fat­ty acid).

The study … exam­ined 402 peo­ple with mild to mod­er­ate Alzheimer’s. They were ran­dom­ly assigned to take 2 grams a day of omega‑3 cap­sules con­tain­ing docosa­hexaenoic acid (or DHA) or a place­bo cap­sule. The par­tic­i­pants were fol­lowed for 18 months, and their cog­ni­tive and func­tion­al abil­i­ties were reassessed. They also under­went MRI to look at the brain.

There was no ben­e­fit seen in the patients tak­ing omega‑3 fat­ty-acid sup­ple­ments in either brain vol­ume or cog­ni­tive function.

Com­ments: Does this study mean that DHA or omega‑3 in gen­er­al are not good for the brain? No! This study sug­gests that tak­ing DHA sup­ple­ments after Alzheimer’s diag­no­sis is not help­ful. Pri­or evi­dence shows that omega‑3 con­sump­tion (espe­cial­ly DHA) long before the onset of Alzheimer’s symp­toms reduces the risk of devel­op­ing the dis­ease. Indeed, sev­er­al stud­ies have shown that eat­ing fish (the pri­ma­ry source in our diet of omega‑3 fat­ty acids) is asso­ci­at­ed with a reduced risk of cog­ni­tive decline or dementia.

The authors of the JAMA study also spec­u­late that DHA sup­ple­ments could be used as a treat­ment for peo­ple who have not yet been diag­nosed with Alzheimer’s but are already devel­op­ing demen­tia pathol­o­gy in their brain: “Indi­vid­u­als inter­me­di­ate between healthy aging and demen­tia, such as those with mild cog­ni­tive impair­ment, might derive ben­e­fit from DHA sup­ple­men­ta­tion, although fur­ther study will be nec­es­sary to test this hypoth­e­sis.” 


  1. Jenny Brockis on November 3, 2010 at 11:21

    Thank you for your com­ments Pascale.
    A sim­i­lar study from the Karolin­s­ka Insti­tute pub­lished in JAMA in Octo­ber 2006 not­ed that Omega ‑3 sup­ple­men­ta­tion (they used DHA and EPA) was only of ben­e­fit in a small sub­group of their study who had only very mild cog­ni­tive impair­ment. Their rate of cog­ni­tive decline was slow­er over the 6 months than a con­trol group. They also made the com­ment that a pos­si­ble rea­son why the pos­i­tive effects were only seen in those with very ear­ly stage dis­ease, is that there may be a crit­i­cal peri­od of sev­er­al years before the dis­ease man­i­fests itself clin­i­cal­ly, where­by the anti-inflam­ma­to­ry effect of the fish oil may be able to exert an effect on the neuropathology.

  2. Pascale on November 4, 2010 at 6:41

    Thanks Jen­ny: Very inter­est­ing and com­ple­men­tary to the orig­i­nal post!

  3. Gil on November 23, 2010 at 9:20

    Thank you for post­ing this arti­cle. I do feel that sup­ple­ment­ing with CoQ10 and Omega’s can improve peo­ple’s over­all health and hope­ful­ly delay the onset of cer­tain dis­eases and sick­ness­es. I would assume that it would be very hard to reverse these effects once you are already sick. Pre­ven­tion is Key!

  4. Anne Vanderlaan on November 30, 2010 at 2:08

    The study in itself did not even hit upon the ther­a­peu­tic dose of fish oil at 10 grams per day. Also, in my research as a PhD in psy­chol­o­gy at Say­brook Uni­ver­si­ty have found that if a per­son uses the wrong kind of veg­etable oils in their meals it will can­cel out the DHA or omega‑3 on a cel­lu­lar lev­el. I have had suc­cess with peo­ple with demen­tia who took fish oil at a ther­a­peu­tic lev­el, using olive oil in their foods and using butter.I have been research­ing omega‑3 for two years now and have seen dras­tic results in peo­ple who have used fish oil.
    I would like to see a study where they also use raw foods at every meal with fish oil and the right sup­ple­ments. I wish you could post the whole arti­cle so that we can see if those issues were cov­ered. I am sure that over a mil­lion dol­lars was spent on this study.

  5. Dr. Pascale Michelon on November 30, 2010 at 9:49

    Thanks for shar­ing your results Anne: Very inter­est­ing! I can­not post the whole orig­i­nal arti­cle but here is the reference: 

    Quinn, Raman, Thomas, Yurko-Mau­ro, Nel­son, et al. (2010). Docosa­hexaenoic Acid Sup­ple­men­ta­tion and Cog­ni­tive Decline in Alzheimer Dis­ease. A Ran­dom­ized Tri­al. JAMA, 304(17):1903–1911.

  6. Christopher on November 30, 2010 at 10:27

    Pret­ty intrigu­ing infor­ma­tion there Anne! I’ll fur­ther research this, but I had no idea that cer­tain veg­etable oils can can­cel out the omega‑3 I take on a dai­ly basis. I usu­al­ly stick with olive oil when cook­ing, but I’ll use veg­etable oil as a substitute.

  7. Susan on November 30, 2010 at 1:42

    @Anne, you men­tion 10 grams as a ther­a­peu­tic dose. How much should one take for a pre­ven­ta­tive dose? Thank you!

  8. Daniel on December 2, 2010 at 3:55

    Is DHA need not to be con­sumed ? Often in adver­tise­ment we see that the drink has DHA that could help brain. Is that infor­ma­tion true?

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