Flax Seed and DHA

[GenTDuke]

Hey guys I have come accross this artical which is worrying me a bit as it suggests I am not getting enough DHA from my flax seed oil, any informed opinions would be appreciated.

"Contrary to previous speculation, new evidence has shown that the body cannot make adequate amounts of DHA from flax seed oil[4]"
[4] Francois CA et al. (2003). Am J Clin Nutr 77: 226.

It goes on to suggest we should source our DHA from supplements marine algae

http://www.healthspan.co.uk/articles/Ju ... e1_aw.aspx

Regards
Tom

[Pete]

This is a relatively new concern, that some people may not be able to convert ALA into DHA in sufficient quantities. I'm actually concerned enough to be considering supplementing with DHA (you can get DHA that come from seaweed extract & marine algae, so I've been informed). If anyone out there has any brand details for there countries that would be a great help. Also we need to keep an eye on how this develops, it might just be a scare, that comes to nothing, or something we have to take into account in the future? I am gathering all the (limited) research I can find to see if it forms a valid argument or just another piece of data brought forward by the fish oil manufacturers - fish oil is high in DHA (& mercury & contains PCPs etc).
Also anyone stumbling across research or articles about this maybe they'll forward details to us?
I'll have to get back to you with a view (note that's all it will be, a view) in a while once I find time to really hit pubmed & consult with a few people who are up on nutritional matters.

[i live in omaha]

I read about this from a beginning vegan book about 6 months ago. I can't remember the book (i can post the title later this evening when i get home from work), but i know it was written by two nutritional MDs here in the states.

Since then i have been downing DHA suppliments that i get from www.veganessentials.com , more specifically these: https://secure7.nexternal.com/shared/St ... D=161&All=

[Pete]

Got a reply from the author about the missing research for article http://www.healthspan.co.uk/articles/Ju ... e1_aw.aspx :

Contrary to previous speculation, new evidence has shown that the body cannot make adequate amounts of DHA from flax seed oil[4]. .....4] Francois CA et al. (2003). Am J Clin Nutr 77: 226.

Got this reply:

The article can be found on the Americal Journal of Clinical Nutrition and this can be located on www.ajcn.org/cgi/content/full/77/1/226

So anyone fancying a look can check it out (I'll have a read when I get a moment).

[i live in omaha]

I found the book. It's called Becoming Vegan by Brenda Davis, RD & Vesanto Melina, MS, RD. (rd = register dietician)

Basically your body can usually convert certain types of fatty acids into othe rtypes of fatty acids, except in the case of DHA and EPA. Vegetarians/vegans usually get enough of the other fatty acids, except DHA, from their daily intake of foods. DHA and EPA are most commonly present in fish, eggs, poultry, seaweed, and microalgae (in the latter two . Since most vegans don't eat microalgae salads or seaweed cookies in the amount that they would need to to gain sufficient amounts of these fatty-acids, it might not be a bad idea to suppliment DHA. (DHA can be converted to EPA by the body, so supplimenting just DHA should be fine).

Here is a snippet from the book on page 65. Comments i added are in parentheses:

With vegan intakes of EPA and DHA typically being zero and serum levels low, an important question arises: Can vegans sufficiently convert parent fatty acids, LA and LNA to longer chain fatty acids or do they need a direct dietary source?
While conversoin of LA to AA (two essential fatty acids) is rarely a problem for vegans, conversion of LNA to EPA and DHA (three other essential fatty acids) is far less efficient, with rates shown in the chart to the right (chart not included, but you get the idea). DHA consumed directly from microalgae can be converted back to EPA from DHA.

And so forth.

And for what exactly DHA is:

Docosahexaenoic acid (DHA) is not converted to eicosanoids (umm?) but is an important structural component of the gray matter of the brain, the retina of the eye, and specific cell membranes, and is found in high levels in the testes and sperm. Low levels of DHA have been associated with several neurological and behavioral disorders such as depression, schizophrenia, Alzheimer's disease, and Attention Deficit Hyperactivity Disorder. It is also linked to reduced visual and brain development in infants.

But i think it is important to note that "low levels of DHA associated with several neurological disorders" means that folks with these disorders have been observed to have low levels of DHA. Low levels of DHA is not necesarilly the cause of the disorders, and could simply be a symptom.[/quote]

[Pete]

As far as I (or anyone else I've spoken to) know, there is no research on DHA level in vegans. This issue has arisen on the back of the ALA/LA imbalances that are implied in problems that some vegans have encounted, but has no research to back it up, unlike the ALA/LA question.
There is some no evidence that people who get a good balance of ALA/LA have any problems converting sufficient amounts to DHA.
That's not to say that you don't need to supplement, but at the moment I wouldn't put it high on the list of worries. If you have spare cash, & it's causing you worry, then there's no reason not to supplement with DHA, if you wish.

[Scott]

Good for Pete to find a description of the study.

One should always find the source then examine how each study was performed. Which cannot really be done unless you were there overseeing everything.

This particular study is likely done by first year students for one of their weekly assignments.

Seven women participated in the study. This alone renders the study useless, hopefully for obvious reasons.

Unfortunately, very few studies I come across have enough participants from a good cross-section of society/culture/nationalities/location/etc. Additionally, the testing methods are often conducive to inaccuracy, cross-contamination, and a variety of other faults. Numbers can easily be manipulated in favour of the conclusions the study is trying to produce and conclusions can we worded in such a particular manner too. The same study performed hundreds of times will almost always result in completely different outcomes. Every high school student knows this from simple experiments done in the science class. Everyone is getting different numbers doing the exact same experiment. It’s no different for the so-called “scientists”.

Ignoring the only seven participants how was the breast milk collected? Were all these women at the same stages of pregnancy? Was the milk collected at the same time of day? Was the baby hungry or not? Was the baby sick or not? Was the breast milked for 5 minutes or 30 minutes? Was it pumped out, or sucked by the baby? Was the sample taken at the 5 minute mark, or the 30minute mark? The first milk to come out of the breast is watery. It takes perhaps 10 minutes to get to the really milky substance. At night, the milk tends to be much fattier. There is a symbiotic relationship between the mother and baby and whatever the baby needs, the mother’s breast milk will adjust. What was the laboratory technique used to count these fatty acids? Remember, “scientists” count calories by burning things – totally ridiculous!!

I’m just pointing out how grossly inaccurate “studies” are. Never trust them without detailed investigation. Even then, take the conclusions with a grain of salt.

[Pete]

Hi Scott,
welcome to the list mate!
Even with the flaws in the study, if you look at the results. I don't see why Dr. Ann Walker concluded what she did did? Point one the study only noted CHANGE in the DHA levels & those levels remained constant (possibly at the correct levels for their child?).
Also, the studies weren't of vegans, so it would be hard to extrapolate the finding to vegans.
Also you often need to lower the amounts of omega 6, while raising the amounts of ALA to get DHA production going.
Four weeks is a ridiculously short amount of time to show the effects of a change of diet.
From the sounds of it the participants collected their own samples...

...and another subject never collected the baseline breast-milk samples...

Add that to the stuff you pointed out & the study was pretty much inconclusive & didn't really do much to forward our understanding of the needs of either lactating mothers or the general population.
Hopefully we'll get some more indepth & better thought out studies as time goes on.

[Malcolms Billy]

The DHA topic was also discussed on veganbodybuilding, and Pat Reeves gave her expert point of view on it. I assume that there is no problem copying it to this board, as she is not online at the moment. Messages go from most recent down.
Hope this is helpful.

See ya,
Billy

************************************************

Yes, DHA is pretty low in all you mention - as it is in soybean, all
beans, flax and walnuts - so not a totally good source without
supplementation. However, this is NOT an essential fatty acid, a
well-functioning body can make the conversion from a balanced vegan diet,
of which seaweed certainly plays its part. There is only a 2-5% for DHA
and 4-10% for EPA conversion for the average person, so most vegan people
(with conversion problems) require approx 1,000mg each day - not easy from
foods! Also anti-oxidants at a rate of 20iu of Vit E to each 2 grams of
DHA is required . One way of ensuring a good balance is to drastically
reduce ingestion of all omega 6 containing items, whilst increasing
omega-3 intake. Hope this helps.



Not sure of the quantities, but I'm pretty sure that seaweed has very
little DHA, spinach will have a tiny amount as the total fat content is
minute, not sure about walnuts, I know they have both ALA & LA in them,


Hi!
Yes, there are certain conditions under which people will be resistant
to exchange their ALA to DHA,. This is not usually a major problem. One
such situation is a failing thyroid. I have had to put some patients in
this situation directly onto an absorbable form of DHA, though this is
pretty rare. Pat.

[veganmike]

I went very quickly through the Americal Journal of Clinical Nutrition articles and found that the study lasted for 4 weeks.

But in his article "Staying a healthy vegan" (available at veganhealth.org) Jack Norris states:

"Limiting n-6 intake and making intake of LNA 1.5% of calories will enhance conversion of LNA to EPA and DHA; it can sometimes take a few months of following these recommendations to build up DHA".

So maybe it's just a matter of time when your body starts converting LNA int DHA.

Somebody contact Jack about it and his sources.

p.s. I'm new here. My name is Michael, I'm from Poland.

[willpeavy]

At http://www.vegsource.com/campbell/messages/5471.html it says,

"a tablespoon of flax oil would only result in the synthesis of about 30 mg of EPA - far less than the recommended daily intake of 220 mg."

The research cited in the article was done on people who eat beef.

---------------------------------

Does anyone have any links to reliable articles (or some other reliable source) about how much seaweed/algae someone would need to eat to get the recommended allowance of EPA/DHA? I did a search and all I found were links to sites trying to sell me seaweed...

[willpeavy]

"Limiting n-6 intake...

What is "n-6"? And what foods is it in?

[veganmike]

These are Polyunsaturated Fats.

"Omega-6s (n-6):

- Building blocks for hormones that increase inflammation and blood clotting.
- Linoleic acid is the most prevalent omega-6 in plant foods.
- Prevalent in corn, sunflower, "vegetable," soy, and safflower oils.

Most vegans get too much Omega-6 fat, and should limit these oils, especially in cooking."

http://www.veganhealth.org/shv/

[Renecarol25]

Thanks veganmike I did not know that about the Omega-6s. I'm currently taking 2 teaspoons of flax oil a day. Which is better that what I was doing.. 3 pills a day which equal about 1 tsp.. and before that not at all. So I don't guess I'm too worried about not getting enough Omega-3s cause I'm getting more than I was.

Oh yeah.. I like the oil much better than the pills. The vegitabs kept melting in my mouth and the tasted something awful. With the oil I can get it down my throat before I have to taste it.
Rene

[Pete]

The DHA issue has not been conclusively proven one way or the other. It is dependent on thyroid health & EFA (essential fatty acid) intake. Also the question of vegans & DHA hasn't even been studied, so we are all in the dark. The best method might be to look for research on inland cultures that wouldn't have sea-foods or other DHA rich sources available & see if they've had/got problems with low DHA. Here's a quick guide to fats by Jack Norris http://www.veganhealth.org/shv/ for those not knowing their omega 6's from their transfatty acids. As well as links to further reading.
I for one would be glad to donate a sample of blood to have my DHA levels tested as it would be interesting to see (& important for optimum growth I'd have thought) to know if I was producing enough DHA for all my needs?
It's important to remember that all the research has been of side-issues, breast feeding or those with damaged thyroid etc, not on whether a healthy, trained, vegan can produce enough DHA.