14 replies to this topic

[zoolander]

Hold the press! DHA is important for brain function during aging

Omega-3 fatty acids, energy substrates, and brain function during aging.

Freemantle E, Vandal M, Tremblay-Mercier J, Tremblay S, Blachere JC, Begin ME, Thomas Brenna J, Windust A, Cunnane SC.

Research Centre on Aging, 1036 Belvedere Street South, Universite de Sherbrooke, Sherbrooke, Que., Canada J1H 4C4.

The maintenance of optimal cognitive function is a central feature of healthy aging. Impairment in brain glucose uptake is common in aging associated cognitive deterioration, but little is known of how this problem arises or whether it can be corrected or bypassed. Several aspects of the challenge to providing the brain with an adequate supply of fuel during aging seem to relate to omega-3 fatty acids. For instance, low intake of omega-3 fatty acids, especially docosahexaenoic acid (DHA), is becoming increasingly associated with several forms of cognitive decline in the elderly, particularly Alzheimer's disease. Brain DHA level seems to be an important regulator of brain glucose uptake, possibly by affecting the activity of some but not all the glucose transporters. DHA synthesis from either alpha-linolenic acid (ALA) or eicosapentaenoic acid (EPA) is very low in humans begging the question of whether these DHA precursors are likely to be helpful in maintaining cognition during aging. We speculate that ALA and EPA may well have useful supporting roles in maintaining brain function during aging but not by their conversion to DHA. ALA is an efficient ketogenic fatty acid, while EPA promotes fatty acid oxidation. By helping to produce ketone bodies, the effects of ALA and EPA could well be useful in strategies intended to use ketones to bypass problems of impaired glucose access to the brain during aging. Hence, it may be time to consider whether the main omega-3 fatty acids have distinct but complementary roles in brain function.

PMID: 16829066 [PubMed - as supplied by publisher]

[opales]

Very interestesting. This seems to directly oppose the accelerated aging through fish-oil hypothesis.

[scottl]

:-)

This reinforces my point. Stick to the known..."physiology level" benefits we are sure of to optimize health here and now vs theoretical molecular level stuff which may or may not do anything for extending life. I can't think of examples now, but as I said in Michael's supp regimen thread, I wonder if this a systematic error some make (to be sure perhaps I'm overly biased in favor of the "physiology level" stuff, given my background).

This would also support the case for fish oil over flax, no?

[opales]

:-)

This reinforces my point.  Stick to the known..."physiology level" benefits we are sure of to optimize health here and now vs theoretical molecular level stuff which may or may not do anything for extending life.  I can't think of examples now, but as I said in Michael's supp regimen thread, I wonder if this a systematic error some make (to be sure perhaps I'm overly biased in favor of the "physiology level" stuff, given my background).

This would also support the case for fish oil over flax, no?

Actually it seemed they contend that ALA itself has value beyond conversion to EPA & DHA, so both flax and fish would be needed.

Regarding "systematic mistake" I think you are being black and white here. Obviously proven (short term) benefits carry more weight than molecular (or animal data) speculations, but that does not mean we have to totally ignore that speculation. It's like putting your head into the sand because not wanting to face the reality but some wishful interpretation of it. And obviously some "molecuar speculations" have better groundings than others. But granted it is possible that due to nature of human cognition the speculative parts get weighted too high, IMO this might stem from a common human bias of assigning equal probabilities (in ones mind) to all presented options, thus the likely events get weighted too low and unlikely events get weighted too high. I can't remember the name of that particular bias.

I would estimate though that positive speculations based on preliminary in vitro and animal studies is more rampant than any negative speculations based on data of similar weight.

However, regarding discussions here, I would say mostly the issue has been the interpretation of "known" rather than any speculations about long term effects. You asserting beneficial "short term" effects of say high amount C or B vitamins are not approved by scientific community (and it appears that even fish oils benefits have been overestimated at least in heart disease), and are IMO based on your rather wishful interpretation of evidence for efficacy, in addition to assigning unforeseen adverse consequences having neglible probability (it might help and it can't hurt fallacy). As Michael mentioned in his personal regime post (which is what I have been trying to futilily point out) is that even seemingly safe substances such as vitamins might have unforeseeable consequences as shown by various examples he provided. To believe that we have discovered all of adverse consequences relating those substances (and making Ortho Core is the final word in vitamin supplementation) seems naive. Still, it might be that the possible corrections of deficiencies that stem from individual variations in genetics and eating habits are enough to offset the possible misdosings in other vits & mins, thus making the net effect positive. However, we don't have actual studies proving that, so it's a leap of faith, especially for most people here who make an effort of eating a healthy diet and thus (more) unlikely being deficient in any particular vitamin.

With such high uncertainties regarding many current interventions (outside the basics everyone should know from high-school) and the rather neglible expected positive value anyway, especially for non-CR people, I honestly feel most people efforts would be better spent in advocacy, spreading the meme and enhancing the science of future therapies (with whatever means they have), rather than trying to optimize every single aspect of one's lifestyle.

Sorry for drifting a little off topic, I have not ranted for a while..

[scottl]

Feel free to rant.

“You asserting beneficial "short term" effects of say high amount C or B vitamins are not approved by scientific community (and it appears that even fish oils benefits have been overestimated at least in heart disease), and are IMO based on your rather wishful interpretation of evidence for efficacy”

Opales,

What you seem not to have grasped is that my enthusiasm for supplements arises in part from the major difference they have made in my health and the health of many people I have recommended them to. In addition, consuming 500 mg hourly of vit c at the start of most illness and feeling the illness fade i.e. I feel instead of sick, almost normal within a few hours…just a bit tired, is a reminder if I need any, of the power of supps. If I stop taking the vitamins, I feel shitty again.

Nobel Prize winning scientist Max Planck on the scientific community:

"An important scientific innovation rarely makes its way by gradually winning over and converting its opponents… What happens is that its opponents gradually die out and that the next generation is familiarized with the ideas from the beginning"

Please read up on the story behind the acceptance of H. Pylori as the cause of ulcer disease to see how science progresses. More needs to be said, but not tonight.

[opales]

What you seem not to have grasped is that my enthusiasm for supplements arises in part from the major difference they have made in my health and the health of many people I have recommended them to.  In addition, consuming 500 mg hourly of vit c at the start of most illness and feeling the illness fade i.e. I feel instead of sick, almost normal within a few hours…just a bit tired, is a reminder if I need any, of the power of supps.  If I stop taking  the vitamins, I feel shitty again.

I am not saying anecdotal evidence, which you are describing here, is *absolutely useless* (certainly many medical science innovations probably stem from individual clinical observations that accumulate into hypothesis in the mind of some researcher), but it is VERY weak evidence. Especially in this case as vitamins have been in focus of science for last thirty years and there have been various trials showing nothing of the effects you describe. And anyway long term effects are almost impossible to detect via such method.

Nobel Prize winning scientist Max Planck on the scientific community:

"An important scientific innovation rarely makes its way by gradually winning over and converting its opponents… What happens is that its opponents gradually die out and that the next generation is familiarized with the ideas from the beginning"

Please read up on the story behind the acceptance of H. Pylori as the cause of ulcer disease to see how science progresses.  More needs to be said, but not tonight.

I do think it is rather amusing you cite Planck, a proponent and follower of rigorous scientific method, as somehow supporting your case. Sure on some level new science has to go againts existing paradigms for progress to take place, but there certainly are limits to that too. Many alties stuff very clearly surpass that limit, such as some claims of homeopathy.

[FunkOdyssey]

Very interestesting. This seems to directly oppose the accelerated aging through fish-oil hypothesis.

I don't think so. This study suggests to me that older people might have an increased need for DHA compared to younger people in order to ensure optimal brain function. That idea is not incompatible with MR's "DHA accelerates aging" hypothesis, which would apply to the entire organism over its lifetime.

[scottl]

I don't think so.  This study suggests to me that older people might have an increased need for DHA compared to younger people in order to ensure optimal brain function.  That idea is not incompatible with MR's "DHA accelerates aging" hypothesis, which would apply to the entire organism over its lifetime.

So exactly when does brain aging and increased need for DHA begin? To be clear, if one starts to see obvious evidence for cognitive decline at a certain age, then the process that produced gross evidence of it has been going on for some time, unnoticed.

Edit: plus there is evidence that fetuses/infants need DHA for optimal brain developement. So we have evidence that people at both ends of the age spectrum need DHA but on theoretical grounds you'll skip it in the middle. Ohhhkey.

[jaydfox]

Very interestesting. This seems to directly oppose the accelerated aging through fish-oil hypothesis.

I'd like to hear MR's response, but at first blush, I get the impression that this doesn't really discredit MR's hypothesis, it only shows that in addition to mitochondrially-driven aging (which should be slowed slightly by DHA restriction), there are forms/aspects of aging which are accelerated by DHA restriction. This latter aspect might have been properly guessed by those who point to the short term benefits of DHA consumption, but the short term benefits didn't make a proper case that there was a long-term analog (prevention of cognitive decline, AD, etc., considered part of the aging suite).

[FunkOdyssey]

So exactly when does brain aging and increased need for DHA begin? To be clear, if one starts to see obvious evidence for cognitive decline at a certain age, then the process that produced gross evidence of it has been going on for some time, unnoticed.

Edit: plus there is evidence that fetuses/infants need DHA for optimal brain developement. So we have evidence that people at both ends of the age spectrum need DHA but on theoretical grounds you'll skip it in the middle. Ohhhkey.

You raise some good points. I think you are assuming that I have full confidence in the accuracy of MR's hypothesis, which I do not. I have allowed it to influence me to the extent that I supplement with a much lower dose of DHA than is typical (200mg daily). I reason that amount is sufficient to avoid any impairments or symptoms of deficiency without saturating my membranes with DHA and inviting oxidative catastrophe if MR is correct. Hedging my bets, in other words.

[Athanasios]

Remember that MR also saw the value of eating 2-3 servings a fish a week, as have many others. Since there seems to be many gains at this level of intake, and I havent seen much for mega-dosing, it does seem to be a good level of intake to shoot for.

[scottl]

Jay,

I let Michael know of this thread, though we both know how busy he is.


Funk (dang, don't typo when writing your screen name),

I take 400-800 DHA depending (more EPA). I'll hedge my bets by increasing my dose of mitochondrial antioxidants to 600 NAC twice a day and....probably about 300 R-ALA/DHALA/day ....probably should take more.

Cnor,

The term mega-dosing as far as I can tell is a term used by people skeptical of high doses of any nutrient to put a negative spin on it.

Given the DHA infant data, the data above, and the women who survived brain injury (see thread "doctors discover DHA" posted somewhere on the board) my bias is to be sure to have sufficient, if that means I get abit more then necessary, it is worth it to avoid being sure to avoid not getting sufficient.--correction not sufficient, but more optimal.

[xanadu]

I think the term "anecdote" to describe reports of benefits noticed by people using a compound is a perjorative meant to discredit those reports. When something works for you, it's not an anecdote, it's proof positive. It is not weak evidence at all. For the person experiencing the benefits, it is the final word on the subject. It may not be the final word for someone else who hasn't tried it. However, when you hear from a physician who has seen benefits in not only himself but in hundreds of patients, to disregard that is pure foolishness.

I think what people are overlooking or misusing is the risk to benefit ratio. If the benefits are small and the risks great, it's usually better not to try something. If the risks are small and the benefits great, it might be worth looking into. If the risks are zero and the benefits are potentially considerable, it's very foolish not to try it. Take vitamin C for example. The risks of using it, even in large amounts, are next to zero. No one that I know of has died from using C, certainly not in any reasonable dose which would include using a dozen grams a day. How can you not experiment with something like that if you have a condition that "anecdotal evidence" has shown to be treated by it? You have nothing to lose because it's non toxic. The only time it would seem prudent not to try something that there are credible reports of benefits from is when there are known toxicities or when there just is not enough data to know either way.

[scottl]

In case Michael gets to this thread, he should read this also:

http://www.imminst.o...=ST&f=6&t=11534

[zoolander]

FunkOdessey and Michael sitting in a tree.

K. I. S.S. I. N. G

[tung]