Food Freedom Friday Edition 319 - Understanding Omega-3
Omega-3 fatty acids belong to the group of polyunsaturated fatty acids or PUFAs. All PUFAs, including omega-3 and omega-6, consist of long carbon- atom chains. PUFAs have at least two double bonds between carbons in their chain. Both omega-3 and omega-6 fatty acids have important roles in the structure of cell membranes, acting as a source of energy and precursors to bioactive lipid mediators. Omega-3 and omega-6 are considered essential nutrients - the body cannot manufacture them.
Aside from sharing certain characteristics, omega-3 appear to have a more multilayered and complex role in human health including supporting anti-inflammatory activity. Research suggests that a common Western diet includes much more omega-6 than omega-3, which is not optimal for achieving the right ratios for balanced nutrition.
Aside from their structural role in cell membranes, these fatty acids are important in the production of hormones responsible for blood clotting and in the integrity of arterial walls, as well as dampening the inflammatory processes. The three main groups of omega-3 fatty acids are Alpha-linolenic acid (ALA), Eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). They all have different, yet significant roles in the body.
One of the most prominent benefits of omega-3 fatty acids is in regards to cardiovascular health by aiding in the management of optimal heart rate and blood pressure. Boosting omega-3 levels has been associated with lowered inflammation and triglycerides, thus improving blood vessel function and overall heart health. Omega- 3s also fight inflammation, support brain health and normal cognitive function, are imperative for healthy fetal development, combat depression, while impacting diseases of mental decline such as Alzheimer's - just to name a few.
DHA and EPA are the biologically active forms of the Omega 3 fatty acid and, therefore, important for your health.
However, when it comes to omega 3s it’s the ALA, a short-fatty acid, that’s essential. The good news is that ALA, or alpha-linolenic acid, is readily found in many foods!
The less good news is that, while ALA is technically the only “essential” omega 3 (in that you are unable to produce it within the body), DHA and EPA are the biologically active forms of the Omega 3 fatty acid and, therefore, the 2 that are physiologically essential.
What is EPA?
Eicosapentaenoic acid (EPA) has a wide range of applications in the management of numerous health conditions. Along with DHA, EPA belongs to the group of the most abundant fatty acids in the brain and the retina, and it is necessary for optimal brain development and nerve functions.
EPA is commonly found in cold-water fatty fish, including salmon, as well as in fish oil supplements. While fish and seafood are the most abundant dietary sources of EPA, and plant-derived oils and fats do not naturally contain any, lab-grown algae includes a sufficient amount due to the way it is produced.
EPA can also be found in poultry and eggs, but the amount of fatty acids available in these dietary sources is minimal. The recommended dosage of omega-3 fatty acids is 400–600 mg/day, which is often impossible to obtain through diet - especially for those following a plant-based diet.
Functions Of EPA
The main function of EPA concerns lowering inflammation levels through multiple pathways, primarily by inhibiting arachidonic acid (AA), a well-known mediator of inflammation on a cellular level. By increasing EPA consumption, you are limiting the production of AA, which is something DHA cannot do due to its size.
Furthermore, it appears that optimal levels of EPA also support multiple benefits of corticosteroids while avoiding their side effects.
When it comes to depression, brain trauma, and other issues related to brain functions, EPA has an irreplaceable role to play. EPA aids in the management of inflammation of brain cells. Once it has entered the brain, EPA is immediately oxidized. Balanced EPA levels are necessary in order to preserve .
What Is DHA?
Docosahexaenoic acid (DHA) is one of the three main types of omega-3 fatty acids. DHA can be synthesized from ALA, but the amount received through this conversion is minor (only 0.1–0.5% of ALA in the body can be converted into DHA). DHA is mostly present in the membranes of cells, where it has significant structural roles. In addition, DHA is one of the main elements of cellular communication.
Functions Of DHA
DHA is a crucial factor in brain development, tissue growth, and function - especially in infants. Aside from brain tissue, DHA is necessary for the development of eyes in the process of fetal development. DHA levels are of crucially important for fetal and infant development in all phases - especially in the third trimester, and the first few months of the baby’s life.
Furthermore, DHA levels can determine numerous brain functions and cognitive processes in a child, including attention, problem-solving, as well as social, emotional, and behavioral development. A DHA deficiency at an early age can be linked to cognitive issues and disorders, such as learning disabilities.
The importance of DHA stretches far beyond children’s cognitive development. As with an aging body, an aging brain undergoes both physical and functional changes. Consistent, quality DHA consumption through diet or supplementation has been associated with significant improvement in areas such as memory, learning ability, and even verbal fluency, which appears to be a frequent issue with the elderly. Alternatively, low levels of DHA have been linked to cognitive issues such as dementia.
Optimal levels of DHA are also associated with vision development and eye health. DHA has been found to activate an ocular membrane protein, rhodopsin which is responsible for numerous ocular functions, including the thickness and fluidity of membranes, which affects the way the brain perceives the images you see. DHA is also largely present in the retina, optimising its fluidity, integrity, and visual function.
EPA & DHA Together
Obtaining an adequate ratio of EPA and DHA is key to all the benefits omega-3 fatty acids have to offer. One of the benefits achieved only by combining EPA and DHA is optimal fetal development. Research concludes that the optimal amount of fish or seafood for pregnant women would be 8-12 oz a week in order to obtain enough omega-3 fatty acids. Luckily for women who are expecting, especially those experiencing sickness or who simply do not or cannot consume fish, supplementing with ~300–900mg EPA+DHA a day helps obtain sufficient levels of these fatty acids.
Boosting the levels of both EPA and DHA levels through maternal nutrition has been associated with longer gestation and a higher concentration of both fatty acids in newborns. What’s more, combining EPA and DHA has been shown to benefit a healthy pregnancy and support optimal pregnancy length, and reduced risk of preterm delivery. Studies have also highlighted the link between consistent EPA + DHA supplementation and a lowered risk of development of allergies in children due to improved immune function.
Finally, obtaining sufficient EPA and DHA has been associated with strengthened immunity, improved cardiovascular function, promoted overall cognitive functioning, as well as weight management.
What is ALA?
Alpha-linolenic acid (ALA) is one of the primary omega-3 fatty acids, containing 18 carbon atoms. ALA can be converted into EPA, from which DHA can be synthesized, but the conversion is rather limited. Therefore, it is necessary to consume sufficient EPA and DHA. ALA has been recognized as a potential nutraceutical which may have neuroprotective properties. Nevertheless, research concludes that “diet supplementation with high levels of ALA has been seen of little interest as compared to supplementation with preformed EPA or DHA”.
EPA & DHA Synthesis
It takes three reactions in the body to make EPA from ALA and another four reactions to change that EPA into DHA.
In order to successfully complete these reactions, the body needs an adequate supply of B3 and B6 vitamins, magnesium, and zinc.
Without enzymes, converting ALA into DHA and EPA would not be possible.
The greatest inhibitor of this lengthy chemical process for most people is not the absence of nutrients, however, it’s the enzymatic activity (or lack thereof) required to make it all happen.
Enzymes act as catalysts to get things rolling; think of them as the spark needed to ignite the gas on that old stovetop. Without enzymes, converting ALA into DHA and EPA would not be possible.
The enzymes needed in this particular series of reactions are unstable and easily disrupted.
Additionally, enzymatic activity is negatively affected by genetics, age, health, and diet. Too many omega 6 fatty acids, for example, throw off the entire EPA/DHA conversion process.
In Western diets, this problem is more common than given that the omega 6 to omega 3 ratio is seriously out of balance. (For those interested: a healthy ratio of omega 6 to omega 3 is 1:1 or 4:1 at a stretch. Because of the prevalence of vegetable oils, fried foods, and processed fats in the modern diet, however, the current average ratio appears to be closer to 16:1).
Converting ALA to DHA & EPA
As previously mentioned, the rate of conversion from ALA to EPA and then DHA is, unfortunately, not particularly high.
It’s estimated to be around 6% for EPA and 3.8% for DHA.
Factor in the declined rate of conversion when too much omega 6 is present and those (already small) percentages decrease by an additional 40-50%.
When doing the calculations, assuming that most people are at least somewhat out of balance in the omega 6: omega 3 department, that’s a conversion rate of roughly 3% for EPA and 1.9% for DHA.
This is a huge cause for concern because
· Your brain is made up of 60% fat by dry weight.
Of those fats, omega 3s are the most important for ensuring good brain function and structural integrity. DHA makes up 97% of those omega 3s.
Your brain is approximately 58% DHA, but your body is only converting it at a rate of 1.9%.
DHA deficiencies may result in learning deficiencies. A lack of DHA may also lead to sudden-onset Alzheimer’s.
Ensuring you consume even 200mg of Omega 3 DHA a day (through diet or supplementation)) has been shown in some studies to lower the risk of heart attack by 50% (grandma was onto something).
EPA prevents inflammation by inhibiting synthesis of the molecules responsible for the inflammation in the first place.
Inflammation may be responsible for a whole host of diseases including, but not limited to, stroke, heart disease, multiple sclerosis, eczema, and Crohn’s.
Consuming ALA
ALA is not biologically active unless converted into EPA or DHA. For this reason it is unnecessary for your diet or a supplement to include it - as long as you can ensure adequate amounts of both EPA and DHA. Although ALA can be transformed into EPA, and an even smaller portion of EPA gets converted into DHA, this process cannot be relied upon to prevent deficiency, let alone reach optimal levels. A more efficient way to obtain EPA and DHA would be to consume them directly.
How Much EPA & DHA
While there certainly are different opinions and estimations on how much EPA & DHA should be consumed on a daily basis, the golden standard for healthy adults seems to be a minimum of 250–500 mg of combined EPA & DHA, but therapeutic and restorative dosage can be significantly higher.