Monday, October 20, 2008

Alzheimers and omega 6s

My wife picked this up on the BBC news last night. Again, I think we are looking at the shrapnel of a neurological bomb (in a transgenic mouse!). Shrapnel is nasty stuff but not the cause of the explosion. Still, excellent to see that the medics can see that eating "healthy" "vegetables, fruits and nuts" can kill your brain. Excellent, even if the link is a bit tenuous.

Actually, I don't see a lot of omega sixes in fruit and veg, and even in nuts they're nowhere up near sunflower oil....... Bit of a booboo there. The BBC did manage to blame eggs as a source of omega sixes.

When will the link get made between a heart health diet, cardiologists and brain death? Soon, you can just hope.



susan allport said...

Thought you would be interested in this short omega-3 video:

Taka said...

The experts would recommend you to beat the Omega-6 with the Omega-3 fatty acids. But what do you think is the most unstable type of molecule in the body? It's the highly unsaturated PUFAs such as Omega-3s. Most sensitive to oxidative damage and therefore the species with long life spans try to minimize their use as much as possible. Please see the papers by "Hulbert AJ" or "Barja G" in Medline such as

Also the work by Barja is interesting in showing that it's not the carbohydrate but methionine restriction which prolongs lifespan -

Therefore the logic would be to minimize PUFAs especially Omega-3s and reduce methionine in the diet what translates to eating gelatine rather than meat ...

JohnN said...

Ms Allport,
Welcome to the only forum in the web where SFA is King.

Anna said...

Gelatin instead of meat ... sounds like a nice soup to me :-). I keep telling my friends, the way to save money is to buy the cheap bone-in cuts of meat and braise, stew, and make soup with the bones, but everyone keeps buying boneless chicken breasts.

JohnN said...

Peter - I can't quite follow your analogy of a neurological shrapnel. I'm sure it's worth a post sometime in the future. Personnaly, I'm intrigued by the possibility that misfolded protein (PrP) is implicated in a wide rane of chronic diseases from A (Alzheimer's) through DM, Huntington's, Parkinson's to Zombie (just kidding).
Two other comments:
Cahill and Veech (few years ago) wrote about ketoacids (beta hydroxybutyrate) for neuronal protection against Alzheimer's and Parkinson's. Strangely enough, instead of recommending a hyperlipid diet (or fasting) they planned to prepare esters of the ketone for "therapeutic" application.
The membrane pliability that DHA imparts is probably most needed in the brain. Perhaps some resistance to the formation of AB peptide comes from that property.

Anonymous said...
This comment has been removed by the author.
Anonymous said...

Hi Taka,
Re methionine see also here:

paul said...
This comment has been removed by the author.
paul said...

Please can I get info on why is there controversy over the benefit of Omega-3? I seem to see mostly studies that show benefit e.g. this recent one

I understand there will be some papers arguing against omega-3s, but I get the impression that the overwhelming weight of clinical work shows they are beneficial - is it true?


Anna said...


Not sure if your question about omega 3s was answered (I thought Bruce K might jump in first as this is a favorite topic of his). I'll take a stab at it with my simple interpretation.

The various studies show a benefit to Omega 3 supplementation because the typical industrial diet has a very skewed ratio of omega 3:omega 6 fatty acids. As "Western" diets became more and more industrialized in the 20th century (and extremely rapidly since the 1950s), the amount of omega 3 intake has gone down due to a variety of factors (livestock no longer on pasture for most of their food, farmed fish fed grain and soy pellets instead of their natural diet, reduced naturally saturated fats in the diet, etc.). At the same time, consumption of foods high in omega 6 fatty acids has risen quite high, due to increased reliance on grains, industrial vegetable oils, and predominately grain-fed animals). So the typical SAD (Standard American Diet) has an n-3:n-6 ratio of about 1:20 instead less than 1:1 - 1:4 (give or take).

If one supplements omega 3, then the ratio improves, so the studies show demonstrative benefit. That's why we see the push (plus there is omega 3 product to sell).

What the studies don't address, is that physiological need for polyunsaturates is very, very low anyway, and balancing the ratio is insuficient; we also need to reduce consumption of polyunsaturates. Polyunsaturates are very unstable and are often already rancid by the time they are consumed (refining and deodorizing can hide this) which can create changes in DNA and other harmful effects.

So rather than supplementing with lots of omega 3s, one can greatly reduce or eliminate the need to correct imbalanced ratios by eliminating excessive omega 6 consumption (eliminate grains, "vegetable" oils such as corn, soy, etc., seek pastured livestock products instead of grain-fed, etc.).

paul said...

Thanks a lot Anna. That makes it much clearer to me why there seem to be two intelligent but opposing points of view.

About the physiological need for PUFA being very low though, meat and fish contain PUFAs. If those were the core of traditional paleolithic diets in different places, how would it be that we would not make use of those fats and come to be dependent on them? I'm thinking about an 18th century Inuit whose diet was almost solely fish for example (a small pun on the fish back there), it doesn't seem to quite gel that there were PUFA heavy diets over tens and hundreds of thousands of years, but PUFA is not much required. Then again that isn't a very scientific argument, I should think more about what you said :)


Anna said...


I'm no expert on traditional Inuit diets, but I know Inuit diets included more than just fish flesh - they hunted seals, whales, caribou, polar bears, and other arctic mammals, plus birds (& presumably their eggs). They would have been getting plenty of saturated fats and organ meats from these foods to offset the PUFA omega 3 intake from fish.

This PUFA/omega 3 issue is one that you'll have to dig around in a bit and sift through carefully (this blog and Stephan's Whole Health Source are very good places for interesting interpretations of the research) because you won't find much outside the "pro- Omega 3 consumption) mainstream interpretations in the conventional nutrition circles, though it's out there if you dig for it. Ultimately, it doesn't matter much what someone tells you, you have to sift through it and come to your own conclusions. The key is finding enough good credible information sources, not just summaries of epidemiologicial studies one reads about in the mass media. The more I look into the inconsistencies, the more I find cracks in the "official party line" health recommendations that make little sense when I back away from industrial diet contexts and even traditional crop-based contexts, and instead give primary consideration to pre-agricultural human existence. It seems I'm constantly running into "the Emperor has no clothes" when it comes to much of conventional nutrition advice. Once the paradigm shift occurred in my own mind, it made "interpretation confusion" much easier to deal with, because I now filter out a lot of the "mainstream noise" that masks a more complete view. And having a liberal arts/"generalist" education, I don't have a strong science background, limited to mostly a few biology course, a bit of organic chemistry, some cultural and urban geography, plus one nutrition class at the college level (and I barely keep my head above water understanding some of the more technical discussions on this blog at times, though I try). I've learned a lot about biochemistry, physiology, evolution, genetics, anthropology, botany, geology, and more in the process, though, and it's been really fun, though far from complete. Reading about health in the mainstream media just gives me a headache and makes me grit my teeth, so I tend to avoid it now (I also view with a slanted eye a lot of non-scientifically supported "alternative" views, too, at least until I can find corraborating evidence).

My husband is an NIH-supported research biochemist (not in nutrition, though), so I can bounce a lot off him, which is handy (though he is quite busy with grant proposal writing this year because funding is so scarce).

paul said...


Thanks for the correction about the more varied diet of the Inuit. I think I would still come back to the point that Omega fats were to be found in traditional human diet over a very long period, so why would we not adapt to them as nutrients? Your comment about saturated fat 'offsetting' PUFAs implies there is something inherently bad about PUFAs. But they are molecules that have some good structural properties for building brains, so in that sense they are inherently good, and one would expect us to be adapted to extract them from diet. That's what I am not understanding right now. But yes, I will be digging around, and thanks much for the leads,


Anna said...


Well, n-3 and n-6 are essential fatty acids, because we can't make them, but I don't think we need much.

BTW, at this point, I prefer to consume direct omega 3 from animal sources rather than flax seed oil and plant n-3 precursors.

Peter said...


Another long and frantic weekend!

I just have to stay off line long enough and great people give better answers than I could have done!

Thanks all


Peter said...


Just flicking through excitiotoxin diseases, the triad of AD, ALS and PD but short on time. The pathology here seems quite convincing on an excitotoxin basis and if they are PrP producing, that would support my suspicion that PrPs are a product of neuronal damage which happen to be very toxic in their own right, so amplify the problem of excitotoxin injury. Hard to tie this in with the migration of prion proteins through the GI tract and LNs to the CNS though.

Use of ketones to blunt energy depletion in excitotoxin diseases is logical. I vaguely remember Veet as being pretty sensible but I guess no one wants to suggest people eat a high fat diet. A pill with ketone esters would be so much easier/safer (!) than living on cream and egg yolks...


Taka said...

Look at the PMID: 18063921, it supports my view that if any only the Omega-6 is truly essential in small amounts. And the ALEs don't come from sugar but from the unstable PUFAs (PMID: 18721793) though sugar can facilitate the process of their formation.

Peter said...


Your first reference gives no information in the abstract about the cell system they are using, but their conclusions from their data are clearly wrong. The conclusion is NOT a need for EPA, it is for arachidonic acid, freely available from terrestrial animals, especially their brain and liver. This was anti inflammatory. DHA was pro inflammatory and EPA neutral. In what to me is an unknown in vitro cell culture system. I'm not sure how this supports a blanket statement that omega 6 PUFAS are the only truly essential fatty acids and are only needed in tiny amounts in vivo, any more than it supports the need for high dose EPA. Your citation certainly argues against avoiding AA (you say"if any" about a roll for EFAs in general) in their cell culture system. This is exactly the approach which makes Ray Peat unreadable for me!

AGE RAGE and ALE discussed the roll of glycation in lipid peroxidation. What's your problem?

If you had cited this ref 18703134 by the same author to support your BSE comments I would (and in this ref I still am) have been interested.


Robert Andrew Brown said...

Hi all,

I have posted a few time on Stephan,s site.

I like Susan Allport am an author on the subject of Omega 3 and 6. I am currently updating it - hopefully another month or so and the update will be finished.

It is needless to say an immense subject. Here are a few quick observations on EFAs Omega 3 and 6.

The plant based 18 carbon Omega 3 and 6 can only be obtained from food. Animals cannot make them. They cannot be interconverted. Humans and animals can elongate with with varying success to the longer chain fats of the same family.

1. It is necessary to consider the long chain fats [20-22 carbons] to the plant based fats [18 carbons] as they are found in different food chains.

2. Humans needs between 1/2- 2% each of calories of the plant based Omega 3 and 6 fats. There are healthy populations with an Omega 6 intake of under 1%. These figures mirror food chain availability. The PLANT based fats are are more or less balanced and limited in plant food sources with the exception of seeds and nuts. {So a balance of PLANT FATS of between 1:1 -1:2 is probably the ideal)

3. Omega 6 18 carbon linoleic acid is found in higher quantities in plant reproductive material which are seasonal, competed for and energy expensive to gather.

4. Land based sources of the long chain fats AA EPA DHA etc are limited. Eggs (seasonal) are an exception. (AA arachidonic acid 20:4n6)

5. The marine environment is biased towards Omega 3 and mainly long chain fats by a factor of 10:1 Omega 3 to Omega 6 DHA +EPA : AA.

Marine fats would be available all year.

You can eat as much fish ( long chain Omega 3 with a small amount of long chain 6) as you would have got in natural diet.

6. So as a shore line dweller you would have got quite high amounts of long chain Omega 3 and small balanced amounts of plant based Omega 3 and 6, with a seasonal plant based Omega 6 top up.

Overall you would have eaten much more 3 than 6.

7. Where have swopped an excess of long chain Omega 3 DHA and EPA with a little AA for an excess of 18 carbon Omega 6.

8. This has huge health consequences for a mass of reasons, including the promotion of inflammation through the downstream chemicals made from Omega 6, oxidative stress, hormone imbalance, alteration of cell membrane structures etc.

9 I propose for a variety of reasons that Omega 6 is a master regulator of body function and provides a direct link to the fecundity of the environment.

Omega 6 controls breeding, fat storage and metabolism, behaviour including aggression, neural function etc.

10. Because of primarily vegetable oils which are high in Omega 6 we consume not 1/2 - 2% but 8-13% Omega 6 LA and have taken the body outside its Omega 6 operating parameters with disastrous consequences for health, fertility, mental well-being, and with huge excess of Omega 6 LA are creating ever-increasingly aggressive self interested society, so threatening our very survival.

(In respect of long chain fats being easily oxidised - yes they are - that is the point they are needed for brain and eye function - but the body has developed sophisticated anti oxidation protection systems which we downgrade out on through poor diet (minerals iodine vit K etc) excess alcohol etc. 60% of the brain is fat of which 25% is DHA. - And dolphins seem to do well on a diet very high in long chain Omega 3s minerals and iodine)

Robert Brown

Author Omega SIx The Devils Fat


Taka said...

Hi Robert,
nice site you have built. Could you give some example of the "healthy populations with an Omega 6 intake of under 1%" you mention?
Thanks, Taka

Krissie said...

Hello Peter, I have a few questions.
This press release came out in Aug 2009:
and here is the abstract:
A kaiser study over 4 decades showing that higher serum cholesterol in midlife is associated with Alz.Disease and vascular dementia. Any comments?

Also, since you have moved to Glasgow, is there any chance of you holding the conference/talk/forum on health that you had mentioned before? We will drive up to Glasgow to attend!

and, Lastly, any chance of you posting anything in regards to children's health/diet?...even an account on what you have noticed with your child(ren)'s experiences?

OK, one more, on the topic of these comments: if symptoms of an illness improve with o-3 supplementation...should o-3 be taken until the low o-6 ratio in the body kicks in?(I understand it can take about 2 years).

OK, and another one: I thought Ray Peat was unreadable because of his frustrating writing style, but you are saying his science is flawed?

Thank you - a lot; this blog is a gem,

Peter said...

Hi Krissie,

Thanks for the comment, I'll put up some info but I'm just hitting my third 12h shift so it might be a while and as you know there's a lot of stuff on the stones post to work through...