The development of the human cerebral cortex has been linked with multigenerational consumption of oily fish containing essential fatty acids, in particular, DHA and EPA. A decline in proportionate consumption over the last century correlates with the marked rise in lifestyle-diseases, and perhaps even a dumbing-down of the population. Without essential fatty acids (DHA and EPA), humans fall prey to a host of debilitating and lethal chronic diseases, including the big C.
Our focus today is on two long chain Omega-3 essential fatty acids known as EPA and DHA. They are essential because our bodies can’t manufacture them so we must obtain them exogenously, i.e. in our food (1). And when we don’t get them, we're in a whole lot of trouble. Note: ALA and DPA are two additional forms of Omega-3. ALA is typically found in plant sources, however, research suggests the liver's ability to convert ALA into the usable forms (EPA, DHA and DPA) is inefficient (15%) and can be 2.5x lower in men than in women.
Studies of Paleolithic nutrition and hunter-gatherer populations show that human beings evolved consuming a diet containing roughly equal amounts of Omega-6 and Omega-3 fats, and much lower amounts of trans fats than today (2). Historically the best sources of EPA and DHA have been fatty deep-sea fish like tuna, mackerel and salmon. Highland populations would have likely got their DHA and EPA from consumption of wild grazing animals. A newer source includes krill oil which has been inaccurately marketed as more sustainable and bioavailable (14). However, today there is a shift towards consumption of a genuinely sustainable, marine algae source. Interestingly, we find both DHA and EPA in breast milk, so as humans, we're feeding on them from the moment we draw our first breath (3).
In the past 150 years our Western diet has seen the consumption of poisonous Omega-6 fats eclipse that of the life-sustaining Omega-3s. These rancid Omega-6 fats come from vegetable oils and soybeans and from industrial seed oils.
How and why were we lured off the golden Omega-3 path only to find ourselves pinned down in the brambles of an Omega-6 wasteland? Well, like many sad stories of this world, we need look no further than big business to find the cause of our nutritional demise.
The 1970s saw the course of human nutrition steered onto the rocks on the back of Ancel Keys' fraudulent Seven Countries Study which heralded the deadly dangers of animal fat in all its guises. Large industrial seed oil producers in both the U.S and Australia leveraged Keys’ falsified findings, and colluded with government (aka lobbying) to convince the citizens that they should swap out all forms of animal fat for their “heart healthy” chemically processed seed oils (which just so happened to be ultra-cheap to manufacture).
The mainstream media, alongside marketing and advertising propaganda machines went into overdrive to ram the “saturated animal fat is bad” message down our throats, until everyone was eating margarine, cooking with vegetable oil, avoiding fatty meats and fish and only consuming nutrition deficient, denatured, low fat, pasteurized, homogenised dairy. We were hoodwinked on a grand scale.
Omega-6 oils compete with Omega-3 oils for the same enzymes in the body. Excessive Omega-6 intake displaces from cell membranes. The resulting metabolites have opposite effects. Omega-6 oils are the proverbial wolf in sheep’s clothing. Here’s why:
The Central Nervous System
The brain is comprised of a whopping 60% fat (12), of which DHA is the most abundant. DHA is so important to the human body in fact, that it is taken up into the brain and the retina in preference to any other fatty acids and it is found concentrated in the nerve terminals, myelin sheath and mitochondria. It makes up the structure of all nerve transmission membranes.
Prenatal and Postnatal Neurological Development
DHA is essential for the growth and development of the foetal and infant brain and the maintenance of normal brain function in adults. DHA and EPA in the mother’s diet is the best way to enrich those fatty acids in developing brains (4). After giving birth, a woman has half her normal blood levels of DHA. If she fails to replenish these, she will have inadequate levels for breastfeeding.
In the twelve weeks after birth the baby’s brain and nervous system development triples – during this time the infant just can’t make enough DHA for it growth needs, so it is vital that it receives it from the mother (5).
Age related cognitive decline, alcoholic dementia and neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease have been shown to exhibit brain membrane loss of Omega-3s, especially DHA. Patients with low levels of DHA have twice the risk of developing dementia (6).
Depressive patients show significant red blood cell membrane depletion of EPA and DHA and have also suffered membrane oxidative damage (8). Chronic alcohol consumption reduces brain DHA levels with an increased tendency towards depression and violence. Supplementation with DHA in these cases may prevent brain damage from chronic alcohol ingestion (9).
It has been suggested that the large increase in the Omega-6:Omega-3 ratio in the last thirty years has contributed to the rise in asthma, eczema and allergic rhinitis and other inflammatory conditions such as Crohn’s Disease (9,10).
It's estimated that Australians are getting about 160mg of DHA + EPA per day. For disease prevention, the Heart Foundation recommends at least 500mg DHA + EPA per day for children and adults.
You can take higher dosages of up to 2,000 mg DHA/day to address depression, dementia, inflammation and cardiovascular disease. For arthritis pain relief, 3000mg DHA+ EPA per day is recommended, and the Heart Foundation suggests 1000mg from a marine source (DHA + EPA) for those with coronary heart disease, plus 2000mg from plant sources such as ALA. For children, a common starting recommended is 135-400 mg DHA/day. Note that these are not prescriptions. It is best that you consult with a qualified healthcare practitioner, especially if you are currently taking other medication. There is no one-size-fits-all model when it comes to diet, supplementation and medication. For example, Omega 3s taken in conjunction with aspirin can result in an increased risk of bleeding.
Avoid Heavy Metals
The cruel irony is that the precious EPA and DHA are found in the adipose tissue (fat cells) of the fish – the very same tissue where environmental contaminates (read: poisons) bioaccumulate. In this tissue, scientists have found heavy metals such as arsenic, cadmium, lead and mercury, all courtesy of industrial pollutants.
Heavy metals build up in the body over time. If you ingest enough heavy metals, you’re very likely to suffer from cognitive impairment, nervous system dysfunction, blindness, loss of coordination, deafness, development of certain cancers, irreversible liver damage, and eventually, the big D (13).
And as if the heavy metal wasn’t bad enough, some other industrially-created nasties bioaccumulating in fish include Polychlorinated biphenyls (PCBs) that can cause skin problems, muscle spasms, chronic bronchitis and nervous system disorders. There are also dioxins and furans which wreak havoc on the skin, liver and immune system, cause endocrine and reproductive disruptions and encourage the development of some cancers.
I’m not telling you all this to scare you away from fish oil supplements. The market is full of poor quality products so it is vital that you find omega 3 capsules that have been molecularly distilled and purified. Check the manufacturer’s website if they don’t put it on the packaging. Molecularly distilled and purified capsules will be free from toxins and contain higher concentrations of EPA and DHA than you’ll be able to ingest from eating fish. Ask to see the results of a recent lab test. You have a right to know.
A good indicator that a specific brand is of poor quality and has oxidized (become rancid) is that it will taste and smell 'fishy'. This product will have limited health benefits and may even be harmful.
I would also suggest that you purchase from companies that support sustainable fishing/harvesting and who show concern for their environmental impact. WWF and FAO studies suggest global fisheries are at tipping point. Even low-trophic species like krill, first thought to have less of an impact, are now being overfished to feed larger, farm-bred fish species. One option is this Omega 3 supplement from Marine Algae Oil.
Studies are also showing that if you increase PUFAs (polyunsaturated fatty acids) in your diet you also need to eat more vitamin E, as it’s a lipid antioxidant. You should look for a DHA/EPA formula that contains a small amount of vitamin E (aka tocopherols). If you can’t find DHA and EPA combined, you can always supplement separately.
And finally, you’ll know it is time to upgrade from fish oils when, after taking the recommended dose, you find yourself burping some pretty unpleasant (for both you and anyone in your vicinity) fish odours after ingestion! Enteric coated, delayed release formula oil capsules could help.
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7. Ancestral Health Society 2015, Retrieved 1st December 2015, http://www.ancestralhealth.org/
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Retrieved 8th December, 2015.
12. Mercola. com, Fascinating Facts You Never Knew About the Human Brain, http://articles.mercola.com/sites/articles/archive/2009/01/22/fascinating-facts-you-never-knew-about-the-human-brain.aspx, retrieved 8th December, 2015
13. Breyer, M., 2015, The Truth About Fish Oil, http://www.mnn.com/health/fitness-well-being/stories/the-truth-about-fish-oil, retrieved 8th December, 2015.
14. Yurko-Mauro K et al, 2015, Similar eicosapentaenoic acid and docosahexaenoic acid plasma levels achieved with fish oil or krill oil in a randomized double-blind four-week bioavailability study. http://www.ncbi.nlm.nih.gov/pubmed/26328782