Hello everyone,
If you are sure you getting enough Omega-3 - Kudos. But I think that still this article can help you realize how good you are doing to your body.
If you are sure you getting enough Omega-3 - Kudos. But I think that still this article can help you realize how good you are doing to your body.
If you are not getting enough or perhaps you don't know or are not sure - please read on! it's important!!
Why am I saying that it's important?
Because one should nourish his body with everything that that the body needs. If one nutrient is missing, be it a vitamin, a mineral, a fatty acid or a phytochemical - then we are not even in a position to say exactly what is the damage. You see - each nutrient is being used in multiple functions in our body. It's not about 'eat this nutrient in order to improve your blood circulation' - no! if you eat 'this nutrient' - it's going to enable your body to do multiple functions and most of them are not even related!! If you don't provide the nutrient then your body is disabled, you are crippling your body.
Now most of my readers are young enough not to care - they are saying that if they managed to live 30-40 years w/o omega-3 then everything is going to be cool in the future too and there's no need to worry about it. Nothing could be further from the truth. If you misbehave nutritionally then your body can tolerate it for years before you discover that you are in for a big problem.
So after this 'positive' introduction - let's focus now on Omega-3 fatty acids. But first let's get to know the players - the fatty acids.
What is Omega-3? What is Omega-6? What is DHA? What is EPA?
All of the above are unsaturated fatty acids.
Let me explain…
A fatty acid is a long molecule containing a tail built of
many C (carbon) and H (Hydrogen). It can be either saturated or unsaturated
and the following figure demonstrates the difference between saturated and unsaturated fats.
Carbons in saturated
fatty acids are always attached to two hydrogens except for the end of the tail. Unsaturated fatty acids contain at least one
carbon-carbon double bond (The '==' in he figure).
The following table shows the fatty acids that we are going to talk about today. In the table you can see one omega-6 fatty acid and 3 omega-3 fatty acids.
One end of the chain is always CH3 and is called the methyl end or omega. The right end side is always COOH and is called alpha.
If you count the number of carbons ('C') from the omega side of an Omega-3 fatty acid to the first link then you will see 3 such carbons - hence the name: 'Omega 3'. If you do the smae for an Omega-6 fatty acid then you will see that there are 6 carbons.
What are the main benefits of Omega-3 fatty acids?
The Omega-3 fatty acid ALA is defined by the medical world as an essential fatty acids. That is the body needs it but can’t create it – the body needs to get them somehow from an external source be it through food or supplementation.
ALA's major role is to convert to EPA & DHA - which are Omega-3 fatty acids. There's a debate whether it has other roles but with your permission let's focus on the DHA today because this *is* a really important fatty acid.
DHA plays an important role in neural function. Decreases in
plasma DHA are associated with cognitive decline in healthy elderly adults and
in patients with Alzheimer's disease.
A 2010 research conducted over 24 weeks period on 485 elderly people suffering from age-related
cognitive decline (ARCD) demonstrated
improved learning and memory functions which proves that DHA is a
beneficial supplement that supports cognitive health with aging. [1]
A 4 years study involving 815 individuals, reported in the July 2003 archives of Neurology, concluded that "dietary intake of n-3 fatty acids and weekly consumption of fish may reduce the risk of incident Alzheimer's disease" [2]
n-3 fatty acid is the most abundant fatty acid in the mammalian brain. More than 2/3 of the dry weight of the human brain is fat
and ¼ of this is DHA. Structurally it’s
an important building block for the membranes surrounding the brain cell and in
particular the synapses which lie at the heart of the brain function. It is a precursor of membrane lipids and as such is an important component of brain growth and myelination. [3]
Our brain contains ~100,000,000,000 neurons and these neurons are communicating through synapses. Synaptic plasticity is the capability of these synapses to strengthen or weaken over time in response to their activity. Since memories are assumed to be represented by vastly interconnected networks of synapses in the brain - synaptic plasticity is one of the important neurochemical foundations of learning and memory.
Our brain has a protein called BDNF, short for "Brain-derived neurotrophic factor". This BDNF supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses.
Exercise and DHA are linked to the action of BDNF and thus promoting memory and cognition. The following chart says it all [4]
Look! If you are given two options: (1) work on a mathematic puzzle (2) go for a brisk walk - which of the two is going to contribute more to your brain? The correct answer is (2) - indeed! Going into the details of this is beyond the scope of this essay - but I encourage you to read more about it or just to... well.. trust me!
Our brain contains ~100,000,000,000 neurons and these neurons are communicating through synapses. Synaptic plasticity is the capability of these synapses to strengthen or weaken over time in response to their activity. Since memories are assumed to be represented by vastly interconnected networks of synapses in the brain - synaptic plasticity is one of the important neurochemical foundations of learning and memory.
Our brain has a protein called BDNF, short for "Brain-derived neurotrophic factor". This BDNF supports the survival of existing neurons and encourages the growth and differentiation of new neurons and synapses.
Exercise and DHA are linked to the action of BDNF and thus promoting memory and cognition. The following chart says it all [4]
Look! If you are given two options: (1) work on a mathematic puzzle (2) go for a brisk walk - which of the two is going to contribute more to your brain? The correct answer is (2) - indeed! Going into the details of this is beyond the scope of this essay - but I encourage you to read more about it or just to... well.. trust me!
DHA is also essential for eye function (Retina) [5]. It also protects against cardio vascular risks as result of diabetes [6] and has many other functions. As I said generally - one single nutrient can affect multiple functions in the human body. You can't ask what a specific nutrient is good for... because each nutrient is good for so many functions.
How much EPA+DHA do we need?
The American heart association are recommending about 1 gram
of EPA+DHA per day for patients with document coronary heart disease. Other
patients are advised to eat fish at least twice a week. For people without
heart problems they recommend two oily fish meals per week which would provide
400-500 mg EPA+DHA per day.[7]
The Australians heart foundation recommends that people with
heart disease consume 1000 mgs omega-3 per day.[8]
The European Food Safety Authority published a scientific opinion in their 2012 journal were they state that Dietary recommendations for EPA and DHA based on cardiovascular risk considerations for European adults are between 250 and 500 mg/day.
As for the upper bound they are saying that there's not enough data however taking combined EPA & DHA at doses up to 5 g/day do not raise safety concerns for the adult population. [9]
While there's a debate whether Omega-3 supplementation can help with diabetes, it is well established already that Omega-3 doesn't have bad effect on diabetes. Among those taking Omega-3 fatty acids, triglyceride levels were significantly lowered and no significant change was registered in total cholesterol, HDL cholesteol, HbA1c, fasting plasman glucose, fasting insulin or body weight. [10] This fact allows me, as someone who was diagnosed as diabetic - to double down my DHA consumption :)
How can we increase our DHA ?
There are two solutions:
1.
Eat foods rich in ALA and
rely on the body converting from ALA to DHA
2.
Eat foods or consume
supplements rich in DHA directly.
Let’s explore the two options.
The ALA to DHA path
Using this solution we consume food rich in ALA and rely on our body to convert from ALA to DHA. There are two problems with this solution:
- The sources for this ALA are limited and unstable
- The conversion is poblematic and in the process ALA is competing against LA over the same enzymes.
Let's dive in -
Sources of ALA are limited and unstable
ALA is found in green leaves and some oils used for cooking
such as rapeseed oil and soybean oil. Some nuts are particularly rich in ALA. I
constructed the following table based on the USDA data base as it is presented
in the nutritiondata.com web site:
Omega-3
|
Omega-6
|
mono
|
saturated
|
sum
|
||
Sunflower Seeds
|
100 grams
|
0.07
|
23
|
18.5
|
4.5
|
46.07
|
Flax Seeds
|
100 grams
|
53.3
|
12.7
|
20.2
|
9.4
|
95.6
|
Chia Seeds
|
100 grams
|
17.5
|
5.8
|
2.1
|
3.2
|
28.6
|
Cashew nuts
|
100 grams
|
0.06
|
7.8
|
23.8
|
7.8
|
39.46
|
Almonds
|
100 grams
|
5.7
|
11.5
|
29.3
|
11.5
|
58
|
Brazil Nuts
|
100 grams
|
0.018
|
20.5
|
24.6
|
15.1
|
60.218
|
Peanuts
|
100 grams
|
0.19
|
10.535
|
31.4
|
6.9
|
49.025
|
According to the above table flax seeds are a very potent
source for ALA that can later be converted to DHA. But apparently not so…
flax oil is oxidized in 20 minutes at room temperature [11]. Flax oil absorption is
problematic. If you do want to consume flax seeds then you have to grind them and then store them in an opaque container in the fridge. Unsaturated fats are oxydized very fast at room temperature.
A rare type of oil extracted from Clary sage (Salvia
Sclarea) was discovered after a 7 year research conducted at the Volcani
Institute by a team of researchers headed by Dr. Nativ Dudai. This plant is
native to the middle east with some areas in north Africa and central asia.
It’s much more stable and can be absorbed more efficiently by the body.
If we to follow the World Health Organization (WHO) for an
intake of 1-2% of calories from omega-3 fatty acids [12] then for a diet of say 2000
calories per day we shall have to consume 20-40 calories from ALA. Dividing by
9 calories per gram (one gram of fat equals 9 calories), we get 2-4 grams of ALA source per day.
The price for 300 grams Clary sage is 1000 IS here so for a daily
consumption of 3 grams one has to pay 10 IS or 3650 IS per year =~ 1000$. I
think this is prohibitive.
ALA is competing against ALA for the same enzymes used for the conversion
Humans are not good in
the absorption of ALA into EPA & DHA. A paper [13] aggregating data from several studies points out that only 8% of ALA turns
into EPA and only 4% of ALA turns into DHA and claims that “Overall, ALA
appears to be a limited source of longer chain n-3 PUFA in humans. Thus
adequate intakes of preformed long chain n-3 PUFA, in particular DHA, may be
important for maintaining optimal tissue function”
Enzymes that are used for the conversion of ALA are also
used for the conversion of LA, so these two fatty acids are competing on the
same enzymes.
Further more – papers are showing that ALA to DHA conversion is reduced by 40% if LA consumption is
doubled. Apparently both ALA to DHA and LA are fighting for the same de-saturate
and elongate enzymes. It means that there should be a ratio between LA and ALA
consumption in order that conversion shall succeed.[14]
Moreover – some people are limited in their ability to
produce these enzymes, e.g. people with diabetics [15]
As I already mentioned the World Health Organization (WHO) recommends an intake of
5-8% calories from omega-6 fatty acids, and 1-2% of calories from omega-3 fatty
acids. This means that the recommended amount of omega-6 fatty acids relative
to omega-3 fatty acids (or the ratio of omega-6 to omega-3) is 2.5:1 to 8:1. This is a recommendation made for the general
public – and is based on direct intake from EPA and DHA.
Unfortunately the ratio in the standard American diet (SAD)
is between 1:5.5 (In Denmark) and 1:28.8 (in Spain…)[13].
This ratio doesn’t get better with standard vegetarian/vegan diet. Vegans
consume tons of nuts and seeds and you can see from the above table that most
of them contain tons of omega-6 (LA) and not enough enough omega-3(ALA). And indeed a research conducted in 1992 shows that the EPA
plasma levels for vegans were 38% [16]. That's one common mistake for vegans - they think that if they are vegans then they can enjoy as many cashew nuts as they want. No! One should always limit the amount of omega-6 oils.
Consuming DHA directly
Fish are a very good source for DHA which is good news…
however the bad news is that all of them contain mercury which is a very
poisonous metal. Some fish contain more and some fish contain less. For example Mackerels, sharks, swordfish and Tuna have the highest mercury concentration while Anchovies, clams, crabs, herrings, oysters & salmons for example have the least amount of mercury. [17]. By the way other mammals and birds are very low on Omega-3.
So while we want to boost our memory & cognition by consuming more DHA, the mercury in the fish has an adverse effect. A research actually compared the impact of 33 fish species on the IQ of children and found out that in total consuming DHA as well as... Mercury had a negative effect of up to 10 points on the IQ score!!! [18] - so eating fish is not such a good idea.
But there’s no need to eat fish – we can consume DHA from
supplements. For example an Alsepa supplement that contains 180 mg EPA and 120 mg DHA in each
1000 mg capsule. Such DHA supplements have no traces of mercury. ConsumerLab
performed a survey on 68 companies selling DHA supplements out of which 11 had
contamination. Mercury was not found in ANY of the companies surveyed!! [19]
Actually fish don’t produce long-chain omega-3 fatty acids, fish
get their EPA & DHA from plants of the sea: micro algae and seaweed. The
problem is that most of these are not concentrated sources. However micro algae
are a good source. There are many products providing vegan or 'so called vegan' EPA & DHA supplementation of which some are listed in [20]. Some of them are not completely vegan because they are using gel caps.
O-Mega-Zen by NuTru [21] are totally vegan
and contain 300 mg per capsule. These capsules are unfortunately expensive. A combined capsule
containing 40 capsules each containing 100 mg EPA and 200 mg DHA costs 24$ here.
Consuming two such capsules per day should cost 432$ (2 x 9 x 24$) per year + shipping.
Comparing this to
the fish based alternative of Alsepa – we are talking about 100 capsules by Alsepa each containing 450 mg EPA
and 340 mg DHA cost ~90 IS = 26$ and for one year it should cost 26$ x 100 / 30
= 86$.
My personal conclusions
I am going to consume two Alsefa capsule per day
in order to get conbind 600 mg Omega-3 oil per day. This is even more than recommended but surely far from reaching the upper intake limit.
The alternative of converting ALA to EPA/DHA is not
efficient, not stable and not is not for anyone. The ALA sources such as flax
seed are not reliable and the clary sage option costs 1000$ per year.
As for the alternative of getting DHA directly – the alga
vegan option costs 432$ per year comparing to a fish based supplement that
costs only 86$ per year. Getting DHA from micro alga is probably an expensive
business and it indicates that this is not the natural way of consuming DHA.
Our ancestors didn’t collect esoteric micro alga – they were eating fish. Fish
mercury level may be problematic these days so getting the DHA from a quality supplement
makes more sense.
As for the moral aspect of killing fish. I am vegan and I
feel very bad about murdering animals – there’s not a single reason in the
world to eat a poor turkey, I can survive and flourish without the poor turkey,
but if by avoiding these marine based DHA capsules – I may suffer cognitive
decline and memory loss and there’s no reasonable way out of it – then yes, in this case I
shall consume these capsules. In this very specific case - it’s either me or
them.
So by taking 2 grams of fish oil for Omega-3 and 545 mg for Vitman D - I am taking 2.545 grams of fish oil fat per day which translates to 22.9 calories out of ~2500 calories per day - which makes me only 99% vegan...
Aviel.
Sources:
- Yuro-Mauro K. Beneficial effects of docasahexaenoic acid on cognition in age-related cognitive decline. Alzheimers Dement 2010 Nov ; 6(6) (LINK)
- Morris MC Consumption of fish and n-3 fatty acids and risk of incident Alzheimer disease. Arch Neurol 2003 Jul; 60(7) (LINK)
- Petra S. Huppi Nutrition for the brain Pediatric research 2008 (PDF)
- Aiguo Wu DHA dietary supplementation enhances the effects of exercise on synaptic plasticity and cognition. Neuroscience 2008 June 17 (LINK)
- Brett G. Jeffrey, The role of docashexaenoic acid in retinal function; Lipids Sep 2001, volume 36, issue 9, pp 859-871 (LINK)
- McEwen B, Effect of omega-3 fish oil on cardiovascular risk in diabetes. Diabetes Duc. 2010 Jul-Aug 36(4) (LINK)
- American Heart Association Fish 101 Updated Mar 20, 2013 (LINK)
- Australian Heart Foundation Q&A Omega-3: General.
- European Food Safety Authority, Scientifi Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docasahexaenoic acid (DHA) and docosapentaenoic acid (DPA). (PDF)
- Suzanne Hendrich (n-3) Fatty Acids: Clinical Trials in People with Type 2 Diabetes, Advances in Nutrition, an international review journal. (LINK)
- GOTOSEE.co.uk The health & Therapy guide Clary sage seeds - a unique Omega-3 source (LINK)
- WHO Technical Report Series 916 Diet, Nutrition and the prevention of chronic diseases, Geneva 2003
- Graham C. Burdge, Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults, February 2005 (PDF)
- Emken EA Dietary linolic acid influences desaturation and acylation of deuterium-labeled linoleic and linolenic acids in young adult males. 1994 Aug 4 (LINK)
- Artemis P Simpopoulos Essential fatty acids in health and chronic disease, 1999 American Society for Clinical Nutrition
- Sanders, T.A.B. & Roshanai, F. (1992), Platelet phospholipid fatty acid composition and function in vegan compared with age- and sex-matched omnivore controls, Euro. J.Clin. Nutr., Vol 46, 823-31. (LINK)
- Natural resources defense council - protect yourself and your family consumer guide to Mercury in Fish. (LINK)
- Zeilmaker et. al. Fish consumption during child bearing age: a quantitative risk-benefit analysis on neurodevelopment, Food Chem Toxicol 2013 Apr 5 (LINK)
- Natural products Insider - ConsumerLab Tests show Omega-3 Contamination (LINK)
- Tanya Carr - Nutrition and health - Current Topics, table 2 on page 38 (LINK)
- NuTru manufacturer of O-Mega-Zen Web site (LINK)
