Parents, when questioned about their hopes for their children
commonly respond with two main words – ‘Happiness’ and ‘Success’. Now
both of these are of course dependent upon an individual’s perception of
what makes one happy or successful, but one key factor underlies both
of these – the health and optimal functioning of the brain. To
understand how to support the health and optimal functioning of the
amazing Human brain, we need to take a very terse look at how our
massive brain power originally developed.
The divergence of Humankind from our great ape cousins is thought to
have occurred about 5-7 million years ago. I sketched out the
evolutionary timeframe in a previous article.(1) The two main outcomes
of this evolution was our gradual adaptation towards true bi-pedalism
(we are the only species capable of being able to truly do this – other
species can only do so for short periods and are decidedly awkward in
the position), and the conversion from a dominantly plant eating species
to an omnivore (the consumption of both plant and animal foods) – both
of which occurred as a result of the disappearance of the forests in
Africa to a savannah landscape.
These two adaptations had a huge influence on our brain structure –
the bi-pedalism freed our hands so that we could begin using tools, and
the adoption of a more carnivorous diet provided a much more nutrient
and energy dense food which is required for brain power. Despite our
current habits of eating the muscular tissue of animals, our ancestors
prized the internal organs (heart, liver, kidneys, intestines etc) and
especially the brains of their prey. The organs are the most nutrient
dense tissues in the body, with the brain being packed with high
concentrations of long-chain omega 3 and 6 fatty acids.(2)
These factors combined began to make our brains ever so slightly
different from our primate cousins and the land based mammals. During
mammalian evolution all mammals including primates lost brain size –
except Humans.(3) It is likely that the energy and the supply of long
chained fatty acids prevented our ancestors from succumbing to this
widespread brain drain. However, it doesn’t explain the massive leap in
brain power that occurred in our ancestors 150,000-200,000 years ago.
That particular development requires a large supply of a particular
fatty acid called Docosahexaenoic Acid (DHA).
Modern Human brains are in excess of 60% lipid, almost exclusively
DHA.(4) DHA is essential for neurons and other specialised cells in the
body. We can make DHA from the essential fatty acid alpha-linolenic acid
which is found in plant foods, but the conversion is so low that it’s
insufficient to generate adequate amounts of DHA to promote the massive
encephalisation (Brain growth) that allowed Humans to develop the unique
brain power that we have inherited today. The consumption of brains and
other sources of long chained fatty acids would’ve definitely helped,
but to develop brains to this extent needs a much larger and more
consistent supply – that supply can only come from one place – the sea.
It is likely that our ancestors migrated to the southern coast of
Africa and began to scavenge both algae (a single-celled organism that
synthesises fatty acids, particularly Arachidonic Acid, Eicosapentaenoic
Acid, and Docosahexaenoic Acid) and more importantly shellfish.
Although algae contain a high percentage of fatty acids, the total
amount is relatively low, so requires large amounts to be consumed.(5)
However, algae is the main food source of plankton (zooplankton), which
concentrates the algae derived fatty acids into its own tissues, making
plankton a superior source of nutrition to algae – if you can see them.
Plankton is so tiny as to be invisible to Humans – but to shellfish,
plankton is a gourmet meal. Just as the plankton concentrated the fatty
acids into its structure by consuming algae, the same process occurs in
the shellfish, which are easily seen and were readily available to our
ancestors, who at this point had acquired the ability to use tools which
helped to access the shellfish inside their protective shells, on the
southern and eastern coasts (and rivers) of Africa.
With this newly discovered source of nutrition for their brains, our
ancestors already slightly different brain structure began to expand
rapidly especially the pre-frontal cortex which enables us to make
complex plans, decide upon actions, and moderate our social behaviour.
Just the kind of skills you would need to obtain an even more
concentrated source of these powerful fatty acids – the source being
fish, and the skill being fishing.
With the development of fishing, our brains were being supplied with
large amounts of fatty acids and in particular DHA. It was this
nutritional environment that enabled the huge leap in brain power that
allowed us to develop all of the culture that you see around you today
and in our distant past.
So with DHA being so vital in our evolution, you’d expect our brains today to reflect this need. Let’s take a look.
Childhood is a time of rapid brain maturation, connectivity, and
expansion, all of which are associated with brain DHA accumulation.
Infancy especially is also the key period for visual development which
is also thought to be dependent upon DHA. Deficiency in DHA at this time
has been shown to result in poorer visual acuity in follow up tests 4
years later.(6)
There is also indication that supplementation with long chain
polyunsaturated fatty acids improved performance in problem solving at 9
months of age, which is correlated with later IQ and vocabulary.(7)
Low blood concentrations of Omega 3 have been correlated in children
with ADHD and related behaviour or learning difficulties – and shown to
improve upon re-dressing the deficiency status.(8)
A recent study investigated the effects of dietary supplementation
for 16 weeks with DHA or placebo in healthy school children mainly aged
7–9 years who were initially underperforming in reading. As well as
looking at reading, the study sought to investigate the effects, if any,
on working memory and ADHD-like behaviour.(9)
Depending on the initial reading ability DHA had a variable effect on
improving performance with the most significant benefit for those who
began the study with the lowest scores. The children with the lowest
initial reading score demonstrated a gain up to 50% higher than is
generally expected for that time period.
Again like the reading measure, working memory showed an improvement,
although not statistically significant, with increased DHA intake
especially in the individuals with the highest under-performance
initially.
Parents of the children in the study reported significant reduction
in behavioural symptoms. These included hyperactivity and oppositional
behaviour, mood swings and restless-impulsive behaviour as well as total
ADHD-type symptoms (these children were not diagnosed ADHD). Teachers
of the children with the lowest blood levels of omega 3 also noted
increased anxiety.
This is only a tiny fraction of the research on DHA (and an even
tinier fraction on fatty acids in general), however I hope it’s
sufficiently compelling to at least consider investigating the intake of
marine based omega 3 in your children. From the current evidence
intakes of about 1000mg of combined DHA and EPA appear to be sufficient
for health and performance in individuals without any identifiable
condition. In those who do have certain neuro-developmental conditions,
it’s likely that a higher intake is necessary to create a more optimal
environment.
The best source of omega 3 is from sea-food, however the study above
presented data that indicated that almost 90% consumed fish less than
twice per week, and almost 10% didn’t consume fish at all.(10) Two to
three meals of fatty fish per week would provide sufficient omega 3 for
most individuals, however, for those individuals that do not get this
amount the only reasonable avenue to obtain these fatty acids is via a
supplement. Here’s a supplement I use with younger members of my family:
Kids DHA
References:
1- http://wel-paleo.blogspot.co.uk/2013/08/evolutionary-fitness.html
2 – Cordain L, Watkins BA, Florant GL, Kelher M, Rogers L, Li Y.
Fatty acid analysis of wild ruminant tissues: evolutionary implications
for reducing diet-related chronic disease. Eur J Clin Nutr. 2002
Mar;56(3):181-91. Review. PubMed PMID: 11960292.
3 – Crawford MA, Bloom M, Broadhurst CL, Schmidt WF, Cunnane SC,
Galli C, Gehbremeskel K, Linseisen F, Lloyd-Smith J, Parkington J.
Evidence for the unique function of docosahexaenoic acid during the
evolution of the modern hominid brain. Lipids. 1999;34 Suppl:S39-47.
Review. PubMed PMID: 10419087.
4- Crawford MA. The role of dietary fatty acids in biology: their
place in the evolution of the human brain. Nutr Rev. 1992 Apr;50(4 ( Pt
2)):3-11. Review. PubMed PMID: 1608562.
5- Lang I, Hodac L, Friedl T, Feussner I. Fatty acid profiles and
their distribution patterns in microalgae: a comprehensive analysis of
more than 2000 strains from the SAG culture collection. BMC Plant Biol.
2011 Sep 6;11:124. doi: 10.1186/1471-2229-11-124. PubMed PMID:
21896160; PubMed Central PMCID: PMC3175173.
6- Birch EE, Garfield S, Castañeda Y, Hughbanks-Wheaton D, Uauy R,
Hoffman D. Visual acuity and cognitive outcomes at 4 years of age in a
double-blind, randomized trial of long-chain polyunsaturated fatty
acid-supplemented infant formula. Early Hum Dev. 2007 May;83(5):279-84.
Epub 2007 Jan 18. PubMed PMID: 17240089.
7- Three Randomized Controlled Trials of Early Long-Chain
Polyunsaturated Fatty Acid Supplementation on Means-End Problem Solving
in Nine-Month Olds James R. Drover, Dennis R. Hoffman, Yolanda S.
Castañeda, Sarah E. Morale, Eileen E. Birch Child Dev. Author
manuscript; available in PMC 2010 September 1.Published in final edited
form as: Child Dev. 2009 Sep-Oct; 80(5): 1376–1384. doi:
10.1111/j.1467-8624.2009.01339.x PMCID: PMC2757317
8- Bloch MH, Qawasmi A. Omega-3 fatty acid supplementation for the
treatment of children with attention-deficit/hyperactivity disorder
symptomatology: systematic review and meta-analysis. J Am Acad Child
Adolesc Psychiatry. 2011 Oct;50(10):991-1000. doi:
10.1016/j.jaac.2011.06.008. Epub 2011 Aug 12. Review. PubMed PMID:
21961774; PubMed Central PMCID: PMC3625948.
9- Richardson AJ, Burton JR, Sewell RP, Spreckelsen TF, Montgomery P.
Docosahexaenoic acid for reading, cognition and behavior in children
aged 7-9 years: a randomized, controlled trial (the DOLAB Study). PLoS
One. 2012;7(9):e43909. doi: 10.1371/journal.pone.0043909. Epub 2012 Sep
6. PubMed
PMID: 22970149; PubMed Central PMCID: PMC3435388.
10- Montgomery P, Burton JR, Sewell RP, Spreckelsen TF, Richardson
AJ. Low blood long chain omega-3 fatty acids in UK children are
associated with poor cognitive performance and behavior: a
cross-sectional analysis from the DOLAB study. PLoS One. 2013 Jun
24;8(6):e66697. doi: 10.1371/journal.pone.0066697. Print 2013. PubMed
PMID: 23826114; PubMed Central PMCID: PMC3691187.
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