Thursday, September 4, 2008

Omega-3 Fats and Brain Development

Another interesting study that Dr. Hibbeln sent me is about the link between maternal seafood consumption and neurodevelopmental outcomes in children. The study is about as powerful as epidemiology gets, with an enrollment of 11,875 mothers.

The bottom line is short and sweet: compared to the children of mothers who ate 340 grams or more of fish per week, children whose mothers ate very little fish had an increased risk of low verbal intelligence, poor social behavior, poor motor skills, poor communication skills, and poor social development. These associations remained after adjusting for 28 potential confounders, including social status, level of education, stressful life events, smoking, alcohol, and several others.

In support of this association, in another study the four-year-old children of mothers who were given DHA and arachidonic acid supplements had higher IQs than those given "placebo" (corn oil). There have been a number of trials of varying quality that have shown varying results with n-3 supplementation, so I'll leave you to decide what you think of this. A 2007 review I found on n-3 supplementation and brain development states that "the evidence for potential benefits of LCPUFA [long-chain polyunsaturated fatty acid] supplementation is promising but yet inconclusive".

I do think it's interesting to note that the brain has the highest concentration of long-chain n-3 fats of any organ, and eating n-3 fats in the form of fish, fish oil or cod liver oil increases the amount in tissues. Eating too much n-6 depletes the brain of DHA and adversely affects neuron development in piglets. n-3 deficiency affects the release of serotonin (a neurotransmitter) in rat brains.

Put it all together, including the data from the last two posts, and I think there's some evidence that a good balance of n-3 to n-6 fatty acids is important for optimal brain function and perhaps development.


Robert Andrew Brown said...

I totally agree with Stephan, and thank him for his great work and public spirit in maintaining this blog.

Once you read round the subject of Omega 3 and 6 in brain function it is unavoidable that a good Omega 3:6 balance and an adequate supply of long chain fats is essential to brain formation and function at very many levels.

I have seen a number of trials linking DHA to improved formation of brain components like neurons.

Where DHA is short the body uses DPA Omega 6 22:5 n6. [There is also a DPA Omega 3] A limited number of trials suggest that brain components like astrocytes function less effectively with higher levels of DPA n6.

Omega 6 also increases inflammatory and oxidation pressures which are factors in overall brain function.

Many neurological conditions are now recognised as having an inflammatory element. Some are now saying inflammation is a central factor in neurological conditions such as depression. Current treatments may be in part work by controlling inflammation. Lithium is reported as impacting on the Omega 6 pathways.

Lipid status examination of those with behavioural issues including ADHD often show lipid pathway imbalances. Imbalances in gene expression have also been observed.

A better Omega 3:6 profile means better vascular health and so blood supply.

In animals in the wild Omega 3 and 6s are balanced in the brain. A report about zoo animals suggested diet will alter that fundamental balance.

In approximate terms 60% of the dry weight of the brain is fat of which 25% to 35% is DHA and the balance long chain Omega 6s.

This is a link to my web site and a page with NIH videos on Omega 3 6 issues including mental health.

Robert Brown

Author: Omega Six The Devils Fat

Stephan Guyenet said...


Thanks for the additional information. That's interesting about the lithium.

Jeff said...

Hey All,

Fantastic post series.

Maybe you are getting to this, but could you give some guidance as to foods to feed(and not feed) my children or any supplements you recommend for them? I have 2 munchkins at home(1.5yrs and 5yrs) and I want to make sure they get the best I can offer.

I need to go buy Robert's book now. I just got a gift card to Border's for my anniversary.

thanks again,


Stephan Guyenet said...

Hi Jeff,

I'll be going over practical aspects of the 6/3 ratio soon, but here's a preview: the best is probably to avoid n-6 as much as possible and either eat fish or supplement with modest amounts of fish oil.

The worst offenders are industrially produced vegetable oils like corn, soybean, and cottonseed. Traditional fats like animal fat, tropical oils and olive oil are OK.

Robert Andrew Brown said...

Thanks Stephan and Jeff.

Jeff If you are kind enough to buy a copy hang fire for a week or so I am just finishing an additional section on more of the how too with a simple summary as the book as people have asked for one.

Stephan's summary is succinct and accurate. Rather than pre-empt Stephan's how to posts I will add if I can.

Many thanks

Robert Brown

Dr. B G said...


I love the title of your book!! I agree!

Omega-6s as you're strongly aware are also linked to cancers (esp pancreatic), CAD, autoimmunity issues and many other conditions.

Fish oil is used to treat so many refractory cancers, in particular brain cancers and gliomas esp where no other treatment is effective.

We visited Alaska recently and our tour guide Ruth who is a hunter shared with us that we didn't need to really worry so much about the black bears who ate a lot of salmon off the shore. Their temperaments were much better than inland black bears who foraged more and ate LESS salmon/omega-3s.

Interesting observation, eh?

Thanks for your post Stephan -- fantastic! My kids are on Carlson's kiddie lemon-flavored fish oil -- only $10.99 at They don't mind the flavor at all! We've had almost no colds and asthma since we started Vitamin D3 (also important for the B R A I N and cancer-prevention and CAD) and omega-3.


Stephan Guyenet said...

Interesting, I didn't know about the cancer link!

Robert Andrew Brown said...

Dr b g

Thanks for you observation on bears. The impact of EFA on animal behaviour is an issue I raise and the behaviour of bears when fishing is an example I consider.

Thanks for your comment on brain cancers. I have seen and cite trials suggesting cancers in the brain have abnormal lipid profiles with high omega 6s and low 3s. I had no idea Omega 3 were being used in treatment.

I highly recommend "Omega 3 Fatty Acids in Clinical Nutrition" for any one working in a hospital environment.

I have been long asking about the potential for omega 3 infusions as part of a cancer strategy.

Stephan there is a mass of papers and trials implicating higher Omega 6 and lower 3s in a number of cancers through a number of pathways. This is one of my threads on a breast cancer board

Robert Brown


Omega Six The Devils Fat

Thackray said...

Other Omega-3 books:

I would also recommend one of the earliest (2002) Omega-3 books “The Omega-3 Connection” by Andrew Stoll, MD. Dr Stoll is also linked from Dr Brown’s website – it’s a video on bipolar disorder.

I do not recommend “The Omega Diet: The Lifesaving Nutritional Program Based on the Diet of the Island of Crete” by Artemis P. Simopoulos and Jo Robinson. It’s a high carbohydrate, low fat diet with added Omega 3 and lots of canola oil. If you are LC forget this book. Canola oil has an omega 6 to 3 ratio of between 2 and 3 to one and the omega 3 is in the form of alpha linolenic acid (ALA). In the human body ALA can be converted to DHA via a lengthy process that may only be 20% efficient. In some individuals the conversion may not occur at all. I would leave canola oil out of a healthy diet. With canola oil you are sure to get a lot of omega 6’s but a questionable amount of DHA and EPA.


You mention arachidonic acid (AA) supplementation in the third paragraph of your posting. In the abstract, Dr Hibbein mentions the importance of AA but does not show AA as supplemental when describing the test diets later in the abstract. I know that adults can make AA from commonly available linoleic acid (LA). Perhaps this is true at all stages of life.

Philip Thackray

Stephan Guyenet said...

Thanks Philip. About the AA, I don't know how it fits into all this. It's an n-6 eicosanoid precursor so I don't know why they included it in that study. As you said, we can make it from linoleic acid. Of course, there are things like DHA that we can make from precursor fats but not very efficiently. It's possible that our bodies make only enough to avoid frank deficiency. Perhaps Robert knows more about this.

Stephan Guyenet said...


Interesting. One of the things I disagree with Dr. Simopoulos about is the fiber/antioxidant intake of hunter-gatherers. A large proportion of contemporary HGs were complete or almost complete carnivores. The same is probably true of Paleolithic humans. Neanderthals, one of our closest relatives, were also almost totally carnivorous. Those people were obviously not getting much fiber, and not much antioxidants as well, yet they were healthy. The n-3/6 story I can believe, but I'm highly skeptical of the fiber/antioxidant theories.

Jeff said...


The text from your post came out a little jumbled, but I think I got the message. I will be happy to hold off my purchase until you are ready with your other additions.


Dr. B G said...


Some cancer treatment centers already use omega-3's EPA + DHA like Jefferson...(they may be related to WAPer's) I've been curious myself if their success rate is any higher than more well known onc centers?

Jefferson integrative cancer protocol: 4-20 g standard EPA+DHA
(including also vitamin D 25(OH)D goal: 75 ng/ml)

Good luck with your book -- we need more mainstreaming of these relevant topics. For every age esp pre-conceiving and expectant moms! I wish I knew! At least, it's never too late to start good nutrition and health.

Fish oil and reduction of omega-6s are important but VDRs (vit D receptors) in the brain and overall antioxidant status should be emphasized as well. But I am a irritable B E A R when I have insufficient EPA+DHA!

How this related to heart disease is also discussed here!


Robert Andrew Brown said...


Sorry about the scrambled post. I altered it several times and did not read it properly before posting.

AA manufacture.

In the western diet we have much more omega 6 than 3 plant based fat.

The body seems to prefer to convert plant based Omega 3 to the long chain 3 fats IF there are equal or greater amounts Omega 3 than Omega 6.

Where there is excess plant based Omega 6, the excess skews conversion towards Omega 6 AA.


The AA is converted to the inflammatory chemicals and onward products that tie into the immune system, behaviour, brain function, reproduction, new life and everything.

This Omega 6 chemical cascade process requires less energy to trigger than the Omega 3 downstream cascades


More 6 will result in more AA and more onward downstream product.

IN A FEW - they may have blockages in the fats conversion pathways that could stop production of both DHA and AA. This would be an argument for supplementation. The only way to determine if individuals had poor AA status would be testing, which as yet is not commonplace.

Inappropriate AA supplementation would exacerbate the negatives of Excess Omega 6. Administration of PGE2 (a product of Omega 6) induces immune disturbances etc that look like those that occur in illness.

Dr b.g.

Could you please re post the link re DHA in brain cancer as it does not appear to be working. Many thanks for your interest.


Thanks again for all your hard work and setting this topic out so well and informatively.

From what I have read of Western Price's book and other trials relating to non western diets I believe we have the ability to be healthy on a WIDE range of diets based on what was around in nature, meat dairy fish mixed etc.

I do not know enough about the year round Inuit diet to know what else they ate (stomach contents of caribou?)and so comment on their fibre intake on a year round basis, but I take your general point.

Simopoulous's comments were probably made from a mindset looking at the mixed food eaters. A general comment that a combination of processing and shift away from green foodstuffs is resulting in reduced fibre and antioxidants in mixed foods eaters would be a fair one.

Thackray in defence of Simopolous's book whilst agreeing with your reservations as to the books total enthusiasm for canola, I do not think that Simopolous is either for low fat or low calories. I have just bought the book. The book has some clear insights good explanations and is very readable ( more readable than mine if much less comprehensive and original - a message I have taken clearly on board). BUT my comments apply to the written section and NOT the recipes and diets which as you say use liberal amounts of canola, and may not reflect the views expressed in the body of the book on fats and carbs. I am not a nutritionalist and so cannot comment.

I think we are a bit hung up on antioxidants as a panacea at the moment. Presumably animal and fish meat products contain the antioxidants they use as part of the body processes. They are just not the same antioxidants you find in vegetables.

Antioxidants are fire crews and not miracle workers and have specific functions.

Arguably those functions did not include dealing with oxidative stress arising from imbalances in fats metabolism. Trials suggest that antioxidants are not effective at moderating the down stream effects of excessive Omega 6 overload. They may have an effect on the eicosanoid pathway products as fine regulators where the system in in balance, but are ineffective where the system is out of control.

As stated previously I believe that the body was designed to oxidise long chain Omega 3, but does not cope well with Omega 6 as a fuel.

Many thanks

Robert Brown

Author. Omega Six The Devils Fats

Robert Andrew Brown said...

Re Oxidative stress risk posed by DHA.

DHA seems to have its own protective chemicals and mechanisms like neuroprotectins which would be consistent with the body having systems to deal with the necessary oxidation of DHA with minimal damage.

DHA occurs in the marine food chain about 10 time more freely than AA.

AA does not have the same high energy oxidation roles and so logically may not share the same range of protective mechanisms.

Robert Brown.

Dr. B G said...

Click on any of the cancer treatment strategies/protocols
Jefferson Myrna Brind Cancer protocols

This is the best anti-inflammatory diet/approach that I found thus far.


Stephan Guyenet said...


A fair point about the reduced fiber and antioxidants in mixed food eaters. The question is whether those are relevant changes for health, or whether the health effects are coming from some other aspect of the diet change. I'm of the opinion that they're probably just incidental changes.

Vegetable antioxidants don't consistently raise blood antioxidant status, and sometimes actually reduce it. And then there's the question of whether antioxidants improve health in humans at all, which also hasn't been generally supported by intervention trials. And the fiber thing hasn't been supported by intervention trials either.

So I'm of the opinion that gluten grains, sugar, poor n-6/3, and insufficient fat-soluble vitamins are the big players, and most of the rest is just correlated. And of course there may be other factors that have yet to be identified.

Stephan Guyenet said...

Robert, by the way thanks for your help answering questions about omega fats and their downstream products. You are an encyclopedia!

Unknown said...

I totally agree. My son got very sick and then recovered thanks to dietary changes. Fish Oil high in DHA was recommended by a NYU neurologist who became a homeopathic doctor after mainstream medicine couldn't help her children recover from neurological problems. I have a post on the fish oil she recommended my kids to take. I only mention it because Omega 3s are so important for brain development, yet many parents hesitate to give it to their kids because of the taste.

Stephan Guyenet said...


Interesting. Kids need to stop whining about the taste of fish oil. Our parents had to take cod liver oil that wasn't deodorized like the CLO today. Give them a taste of that and maybe they'll be thankful for the fish oil!

Anonymous said...

I think the raw fermented cod liver oil is preferable to deodorized and distilled varieties. That's the oil used in the past by Roman soldiers, Scandinavians, etc. You fill a huge barrel with raw cod livers and then seal it and let it ferment several months. The oil separates, you skim it off, and bottle the result. This oil is tested for heavy metals and found clean. Processed oil seems to be a dangerous modern food. I would avoid the flavored varieties, since they have additives. The raw oil is just fermented cod liver oil.

Here's the main supplier in the US.

Here's a source in the UK, as well.

Stephan Guyenet said...


I saw that. I'm a little skeptical to be honest. Here's why:

"Green Pastures uses a proprietary cold process extraction and cleaning method to produce this pristine and naturally fresh cod liver oil."

What's the cleaning method? Sounds like it could be refined just like other CLOs.

Anonymous said...

They claim the oil is unheated. for cleaning, they probably use a power washer or something. Also you might need an equal dose of high vitamin butter oil if you take high vitamin cod liver oil. I would avoid oil if it isn't "high vitamin", since they often have only synthetic vitamins. Fermentation concentrates vitamins, and makes them more available. When in doubt, I would choose oils which are made without heat or chemicals.

Jim Nikolaus said...

I enjoyed your comments of omega3. I recently found a new source for omega3 that does not come from fish but from a sea mussel from New Zealand. I started taking this supplement and was amazed that it worked so well on inflammation. In my research on omega3 I read a good book. The Queen of Fats by Susan Allport. There are 18 known different omega3's and fish oil only have two. The new supplement I found has 8 different omega3 and is 158 times more powerful than fish oil. It also contains the strongest anti-oxidant on the planet. Both the mussel oil and anti-oxidants are whole food products. I am new to this and I have started a blog to talk about this new supplement. Go to
to see my little blog. Omega3's are needed by all of us. They have been removed from our diets. This removal of omega3 is one of the main reasons for the obesity in the US. I am just trying to let people know about a newcomer into the omega3 arena that has great promise. Have a good day.