6 ms·

Is there any actual clear link between dietary DHA and serum DHA? I’m guessing no. Humans survive on quite a wide range of dietary fat sources and composition.

Is there any actual clear link between dietary DHA and serum DHA? I’m guessing no. Humans survive on quite a wide range of dietary fat sources and composition. I stopped supplementing with fish oil after realizing there’s lots of “science” and few facts.

dilap 8y ago
There has to be, since humans can't make it themselves. (Assuming that's true.)
- WalterSear 8y ago
  They can. > This finding suggests that when animal foods are wholly excluded from the diet, the endogenous production of EPA and DHA results in low but stable plasma concentrations of these fatty acids. https://www.ncbi.nlm.nih.gov/pubmed/16087975 https://www.ncbi.nlm.nih.gov/pubmed/16087975
  - dilap 8y ago
    TIL. Thank you.
  - knodi123 8y ago
    And yet in the article, > Unfortunately, the body cannot produce DHA on its own, and it must be acquired through the diet. So is Rhonda waaaaay behind the times re: that 14-year old paper? Or are the levels described in that paper negligible? Or did I misinterpret something, or what?
    - WalterSear 8y ago
      Good question. She may be simplifying things, or not thinking of vegans/vegetarians. No doubt it's a suboptimal amount.
gnulinux 8y ago
Fish is not the only source of DHA. Walnuts, acai berry and flaxseeds are also good sources.
- mrob 8y ago
  The only good vegetable source of DHA is some types of algae. The foods you listed contain alpha-linolenic acid, which the human body can convert to EPA and then to DHA, but this is an inefficient process and might not always meet the full requirements for those longer chain omega-3 fatty acids. See: https://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.pdf https://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.p...
  - zeroname 8y ago
    More bluntly, ALA supplementation doesn't work: https://www.ncbi.nlm.nih.gov/pubmed/19269799?dopt=Abstract https://www.ncbi.nlm.nih.gov/pubmed/19269799?dopt=Abstract
    - leekyle333 8y ago
      Walnuts also have a lot of Omega 6 which will lessen the conversion of Omega 3 into useable forms.
      - honzzz 8y ago
        Do I understand this correctly that if I consume a lot of Omega 6 (I love olive oil and nuts and consume large quantities of both) I might actually harm myself? Do I make Alzheimer disease more likely by Omega 6 rich diet? EDIT: I confused Omega 3 <> Omega 6, corrected.
- WalterSear 8y ago
  They aren't. In order to overcome the omega-6 metabolic preference, you need to consume, at a minimum twice as much omega-3 oils as omega-6, but actually closer to 4x. Twice as much omega-3 means eliminating olive oil, soy, most nuts, and many other foods. Or, alternatively, downing a pint or so of flax seed every day.
zeroname 8y ago
Not sure why this is getting downvoted, it's a valid concern. Going by this review, I would say that supplementation does work: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176556/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176556/
virtuallynathan 8y ago
Yes, there is. I have had mine tested as I altered my diet to include more fish roe, fish liver, and fatty fish. I took my omega6:omega3 ratio from 3.5:1 to 1.5:1 in ~3 months. Total O3: 10.2% -> 16.5% DPA: 1.2% -> 3.2% EPA: 3.4% -> 4.3% DHA: 5.4% -> 9.2% I don't have a "before" on the standard american diet, but IIRC the average american has an omega6:3 ratio of about 15-20:1.
- simplecomplex 8y ago
  Serum levels could mean your body has more DHA than it needs, without an established level at which some kind of deficiency develops. I’m not trying to prove a point except this: People who have no regard to dietary DHA and consume no fish don’t exhibit any of the problems claimed in articles and by nutritionists. I’ve been vegan for 20 years for example and my skin is fine, I don’t supplement DHA, I don’t have dementia or other health problems. This contrasts pretty strongly with homocysteine/B12 deficiency or iron deficiency. There’s no good evidence that a clinical syndrome of DHA deficiency even exists. Whenever I dig into studies serum levels are all over the place. There’s quite a lot to be suspect of here. The conclusions drawn from our limited understanding of fatty acid metabolism just doesn’t match reality.
  - virtuallynathan 8y ago
    FWIW, these were not serum levels, this was RBC (red blood cell).
- ardy42 8y ago
  > I have had mine tested as I altered my diet... How/where did you get tested?
  - virtuallynathan 8y ago
    I got it done via OmegaQuant, costs $99 and can be ordered online.

dilap 8y ago

There has to be, since humans can't make it themselves. (Assuming that's true.)

WalterSear 8y ago
They can. > This finding suggests that when animal foods are wholly excluded from the diet, the endogenous production of EPA and DHA results in low but stable plasma concentrations of these fatty acids. https://www.ncbi.nlm.nih.gov/pubmed/16087975 https://www.ncbi.nlm.nih.gov/pubmed/16087975
- dilap 8y ago
  TIL. Thank you.
- knodi123 8y ago
  And yet in the article, > Unfortunately, the body cannot produce DHA on its own, and it must be acquired through the diet. So is Rhonda waaaaay behind the times re: that 14-year old paper? Or are the levels described in that paper negligible? Or did I misinterpret something, or what?
  - WalterSear 8y ago
    Good question. She may be simplifying things, or not thinking of vegans/vegetarians. No doubt it's a suboptimal amount.

gnulinux 8y ago

Fish is not the only source of DHA. Walnuts, acai berry and flaxseeds are also good sources.

mrob 8y ago
The only good vegetable source of DHA is some types of algae. The foods you listed contain alpha-linolenic acid, which the human body can convert to EPA and then to DHA, but this is an inefficient process and might not always meet the full requirements for those longer chain omega-3 fatty acids. See: https://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.pdf https://rnd.edpsciences.org/articles/rnd/pdf/2005/05/r5505.p...
- zeroname 8y ago
  More bluntly, ALA supplementation doesn't work: https://www.ncbi.nlm.nih.gov/pubmed/19269799?dopt=Abstract https://www.ncbi.nlm.nih.gov/pubmed/19269799?dopt=Abstract
  - leekyle333 8y ago
    Walnuts also have a lot of Omega 6 which will lessen the conversion of Omega 3 into useable forms.
    - honzzz 8y ago
      Do I understand this correctly that if I consume a lot of Omega 6 (I love olive oil and nuts and consume large quantities of both) I might actually harm myself? Do I make Alzheimer disease more likely by Omega 6 rich diet? EDIT: I confused Omega 3 <> Omega 6, corrected.
WalterSear 8y ago
They aren't. In order to overcome the omega-6 metabolic preference, you need to consume, at a minimum twice as much omega-3 oils as omega-6, but actually closer to 4x. Twice as much omega-3 means eliminating olive oil, soy, most nuts, and many other foods. Or, alternatively, downing a pint or so of flax seed every day.

zeroname 8y ago

Not sure why this is getting downvoted, it's a valid concern. Going by this review, I would say that supplementation does work: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176556/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4176556/

virtuallynathan 8y ago

Yes, there is. I have had mine tested as I altered my diet to include more fish roe, fish liver, and fatty fish. I took my omega6:omega3 ratio from 3.5:1 to 1.5:1 in ~3 months. Total O3: 10.2% -> 16.5% DPA: 1.2% -> 3.2% EPA: 3.4% -> 4.3% DHA: 5.4% -> 9.2% I don't have a "before" on the standard american diet, but IIRC the average american has an omega6:3 ratio of about 15-20:1.

simplecomplex 8y ago
Serum levels could mean your body has more DHA than it needs, without an established level at which some kind of deficiency develops. I’m not trying to prove a point except this: People who have no regard to dietary DHA and consume no fish don’t exhibit any of the problems claimed in articles and by nutritionists. I’ve been vegan for 20 years for example and my skin is fine, I don’t supplement DHA, I don’t have dementia or other health problems. This contrasts pretty strongly with homocysteine/B12 deficiency or iron deficiency. There’s no good evidence that a clinical syndrome of DHA deficiency even exists. Whenever I dig into studies serum levels are all over the place. There’s quite a lot to be suspect of here. The conclusions drawn from our limited understanding of fatty acid metabolism just doesn’t match reality.
- virtuallynathan 8y ago
  FWIW, these were not serum levels, this was RBC (red blood cell).
ardy42 8y ago
> I have had mine tested as I altered my diet... How/where did you get tested?
- virtuallynathan 8y ago
  I got it done via OmegaQuant, costs $99 and can be ordered online.