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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 13 of 13. This is the beginning of the thread.
Posted by saturn on January 17, 2007, at 9:34:06
I have read that DHA is just a 2-step conversion from EPA, and moreover that a high EPA/DHA ratio is best for treating ADHD, mood disorders, etc...
So would it be sufficient to simply take 100% EPA in order to achieve the mental and cardiovascular benefits of omega 3's? Would you have plenty of EPA and your body would simply synthesize from this the necessary DHA?
Thanks.
Posted by Tom Twilight on January 17, 2007, at 16:28:11
In reply to Is DHA necessary?, posted by saturn on January 17, 2007, at 9:34:06
I'd also really like to know the answer to this one!
I've heard that EPA is the oil you need and that DHA can actually be counter productive, (for mental health at least)
I've also heard that this nonsense and that a balanced blend is best.
I'm so confused..........
Posted by saturn on January 17, 2007, at 17:16:25
In reply to EPA vs DHA-Please explain, posted by Tom Twilight on January 17, 2007, at 16:28:11
> I'd also really like to know the answer to this one!
>
> I've heard that EPA is the oil you need and that DHA can actually be counter productive, (for mental health at least)
>
> I've also heard that this nonsense and that a balanced blend is best.
>
> I'm so confused..........My understanding is that the vast majority of studies using omega 3's for psychiatric disorders such as depresssion, adhd... use either no DHA or a very high EPA/DHA ratio. And yes, I've also read that too much DHA may be counterproductive. Now perhaps the ratio is not as important with respect to non-psychiatric conditions, ie cardiovascular health. I'm still curious as to the efficiency of conversion of EPA to DHA.
You may find this link interesting:
http://www.fattyacidtrip.com/dha-useless-for-treating-adhd/
Posted by Jimmyboy on January 17, 2007, at 17:47:50
In reply to Re: EPA vs DHA-Please explain » Tom Twilight, posted by saturn on January 17, 2007, at 17:16:25
I would like to know this too.. I am not quite sure that no DHA is a good thing though. Seems to me that everyone jumped on that Stoll guy from Harvard's brand "Omega Brite" that is almost all EPA as the model of fish oil for mood disorders.
But , here is a simplistic argument , so feel free to shred it :
Proponents say that "countries that eat a lot of fatty fish have less depression/bipolar". Ok , I believe that.. but.. Do they breed special fish in those countries that only contain EPA in them.. no , it has DHA in there also . I think there is some marketing going on with these 100% EPA formulas , notice how ridiculously much more they are than regular fish oil?
Anyway, don;t know much about it, but its just a hunch, I would like to hear from people who know more ..
JB
Posted by saturn on January 17, 2007, at 20:03:12
In reply to Re: EPA vs DHA-Please explain, posted by Jimmyboy on January 17, 2007, at 17:47:50
>>>
> Proponents say that "countries that eat a lot of fatty fish have less depression/bipolar". Ok , I believe that.. but.. Do they breed special fish in those countries that only contain EPA in them.. no , it has DHA in there also .
Hmmm...Good point. Never thought about that. Actually, I'd be curious to know of any scientific studies actually showing that people who eat lots of fatty fish have less depression/bipolar. I wonder if this is actually the case. Please if anyone is aware of any such studies I'd be grateful for such information.
Posted by Meri-Tuuli on January 18, 2007, at 17:40:08
In reply to Re: EPA vs DHA-Please explain, posted by saturn on January 17, 2007, at 20:03:12
I was wondering why I saw some EPA only fish oil supplements here. Perhaps I'll try some.
Posted by Larry Hoover on January 21, 2007, at 9:38:59
In reply to Is DHA necessary?, posted by saturn on January 17, 2007, at 9:34:06
> I have read that DHA is just a 2-step conversion from EPA, and moreover that a high EPA/DHA ratio is best for treating ADHD, mood disorders, etc...
That "just a 2-step conversion" is really a major hurdle. The efficiency of that conversion is really quite low. It was once believed that plant sources of omega-3 (as alpha-linolenic acid) were sufficient to provide for EPA and DHA requirements, leading to the designation of alpha-linolenic as an essential fatty acid.....but, actual tests showed that DHA yield from labelled alpha-linolenic varied from 0-7%. The real bottle-neck in that conversion was found to be conversion of EPA to DHA. Recent literature has designated DHA as conditionally essential, but the trend is towards fully essential. I lean towards the latter. Getting it pre-formed makes the argument moot, non?
> So would it be sufficient to simply take 100% EPA in order to achieve the mental and cardiovascular benefits of omega 3's?
One of the confounders in understanding what happens is that EPA has an immediate effect (via eicosanoids, which are regulatory or signalling molecules), whereas DHA has long-term influences on the structure and function of membranes. I'm not surprised that DHA effects are not significant over six-week trials, or the like.
> Would you have plenty of EPA and your body would simply synthesize from this the necessary DHA?
If you're lucky.
> Thanks.
Welcome.
Lar
Posted by Larry Hoover on January 21, 2007, at 9:54:42
In reply to Re: EPA vs DHA-Please explain, posted by Jimmyboy on January 17, 2007, at 17:47:50
> I would like to know this too.. I am not quite sure that no DHA is a good thing though. Seems to me that everyone jumped on that Stoll guy from Harvard's brand "Omega Brite" that is almost all EPA as the model of fish oil for mood disorders.
EPA and DHA serve very distinct functions in the brain. EPA is cyclyzed via COX enzymes to produce regulatory molecules such as prostaglandins. These have immediate effect, so that was what was targetted in the mood studies.
> But , here is a simplistic argument , so feel free to shred it :
>
> Proponents say that "countries that eat a lot of fatty fish have less depression/bipolar". Ok , I believe that.. but.. Do they breed special fish in those countries that only contain EPA in them.. no , it has DHA in there also .Indeed. And other psychologically good substances, too. DMAE, for example. And, again blowing nutritional myths out of the water, proteins are not bioequivalent. It has long been held by nutritionists that complete proteins are bioequivalent. Soy protein is the same as meat protein is the same as fish.....well, maybe not so. Rodents fed supposedly bioequivalent complete diets, with the only difference being soy vs. fish protein, had significantly different performance on cognitive tasks. Yes, fish is brain food. Just why is still a major controversy, but the practical difference has been demonstrated.
> I think there is some marketing going on with these 100% EPA formulas , notice how ridiculously much more they are than regular fish oil?
The isolation process is complicated, but you can be sure that price margins are such that profit is made on each part of the cost.
> Anyway, don;t know much about it, but its just a hunch, I would like to hear from people who know more ..
>
> JBI am opinionated. Does that count?
Lar
Posted by Larry Hoover on January 21, 2007, at 10:02:48
In reply to Re: EPA vs DHA-Please explain, posted by saturn on January 17, 2007, at 20:03:12
> Hmmm...Good point. Never thought about that. Actually, I'd be curious to know of any scientific studies actually showing that people who eat lots of fatty fish have less depression/bipolar. I wonder if this is actually the case. Please if anyone is aware of any such studies I'd be grateful for such information.
I haven't seen any studies relating fish intake to bipolar, but there are studies demonstrating relationship between fish intake and depression. For some unknown reason, the effect is more robust in women. Moreover, the effect is non-linear, with higher intakes leading to diminished benefit. That suggests a threshold vulnerability, with declining numbers of people on the below-threshold value side of the normal distribution as the intake level increases. At higher intakes, only those with high standard deviations from the norm still exhibit the vulnerability.
Lar
Posted by saturn on January 22, 2007, at 20:43:12
In reply to Re: Is DHA necessary? » saturn, posted by Larry Hoover on January 21, 2007, at 9:38:59
> > I have read that DHA is just a 2-step conversion from EPA, and moreover that a high EPA/DHA ratio is best for treating ADHD, mood disorders, etc...
>
> That "just a 2-step conversion" is really a major hurdle. The efficiency of that conversion is really quite low. It was once believed that plant sources of omega-3 (as alpha-linolenic acid) were sufficient to provide for EPA and DHA requirements, leading to the designation of alpha-linolenic as an essential fatty acid.....but, actual tests showed that DHA yield from labelled alpha-linolenic varied from 0-7%. The real bottle-neck in that conversion was found to be conversion of EPA to DHA. Recent literature has designated DHA as conditionally essential, but the trend is towards fully essential. I lean towards the latter. Getting it pre-formed makes the argument moot, non?
>
> > So would it be sufficient to simply take 100% EPA in order to achieve the mental and cardiovascular benefits of omega 3's?
>
> One of the confounders in understanding what happens is that EPA has an immediate effect (via eicosanoids, which are regulatory or signalling molecules), whereas DHA has long-term influences on the structure and function of membranes. I'm not surprised that DHA effects are not significant over six-week trials, or the like.
>
> > Would you have plenty of EPA and your body would simply synthesize from this the necessary DHA?
>
> If you're lucky.
>
> > Thanks.
>
> Welcome.
>
> Lar
Hey Lar. Thanks for all the input. I have a further question: Even if the EPA to DHA conversion is inefficient and DHA is fully conditional, is it still not possible (or perhaps even likely) that a high EPA/DHA ratio might be more favorable than a lower one?Thanks...Peace...Saturn
Posted by Larry Hoover on January 23, 2007, at 11:36:10
In reply to Re: Is DHA necessary? » Larry Hoover, posted by saturn on January 22, 2007, at 20:43:12
> Hey Lar. Thanks for all the input. I have a further question: Even if the EPA to DHA conversion is inefficient and DHA is fully conditional, is it still not possible (or perhaps even likely) that a high EPA/DHA ratio might be more favorable than a lower one?
>
> Thanks...Peace...SaturnSure, it's possible. EPA is up against arichidonic acid (AA), the omega-6 eicosanoid precursor. We're flooded with the latter, from vegetable oil sources, and animals fed thereon. It may well be that the best functional defense is high EPA intake. However, DHA effects are not as obvious, and it might be a mistake to adjust intake based on what seems to have an obvious effect.
For example, there is a significant inverse relationship between DHA levels and the risk of dementia: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17101822
Also, a newly discovered substance derived from DHA released from neural membranes, neuroprotectin D1, can only be formed if there is DHA in the membrane to begin with.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16151530Lar
Posted by saturn on January 23, 2007, at 20:58:08
In reply to Re: Is DHA necessary? » saturn, posted by Larry Hoover on January 23, 2007, at 11:36:10
Thanks for the interesting links Lar (btw, do you mind if I call you Lar?).
You've convinced me that DHA is, well, essential. What I am not sure about is the optimum amount of DHA relative to EPA. It has been suggested that too low of an EPA/DHA ratio may be ineffective or even counterproductive for cognitive purposes.
Do you have an opinion on this? For example a company Minami Nutrition boasts a capsule containing 581 mg EPA and 70 mg DHA. That's a ratio of about 7. Nordic Naturals makes one with 850 mg EPA and 200 EPA (ratio of 4.25).
Thanks...Peace...Saturn.
Posted by Larry Hoover on January 24, 2007, at 11:09:23
In reply to Maybe just a *little* DHA? » Larry Hoover, posted by saturn on January 23, 2007, at 20:58:08
> Thanks for the interesting links Lar (btw, do you mind if I call you Lar?).
Of course you may.
> You've convinced me that DHA is, well, essential. What I am not sure about is the optimum amount of DHA relative to EPA. It has been suggested that too low of an EPA/DHA ratio may be ineffective or even counterproductive for cognitive purposes.
Okay, so there's your hypothesis.
> Do you have an opinion on this?
Yes.
> For example a company Minami Nutrition boasts a capsule containing 581 mg EPA and 70 mg DHA. That's a ratio of about 7. Nordic Naturals makes one with 850 mg EPA and 200 EPA (ratio of 4.25).
>
>
> Thanks...Peace...Saturn.I'm leary of reductionist science. The idea that the only beneficial substance in fish is EPA seems unreasonable, to me. The idea that we can isolate one active ingredient.....
I don't think there's an answer for you available solely through intellectual analysis. At some point, you must do the experiment(s).
Lar
This is the end of the thread.
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