Omega-3 fatty acids are a family of polyunsaturated fatty acids (PUFAs), which consists of a long chain of carbon atoms with a carboxyl group at one end of the chain and a methyl group at the other end of the chain. You may have heard of monounsaturated fatty acids or saturated fatty acids in addition to the conversation of polyunsaturated fatty acids however, these PUFAs differ from the prior two fatty acids by the amount of double bonds that are found between carbons within the fatty chain (more on this later as to why this is important).

These fatty acids play a role in everything from cell membrane functioning, cardiovascular health, brain health, inflammation, mood support, hormone regulation and so much more. What is unique about omega-3 fatty acids is the fact that the body cannot synthesize them on their own, yet they are classified as essential fats, meaning they are essential to health, yet people must consume them through food or supplementation.1

Essential fatty acids (EFAs) can be broken down into two main categories, omega-3s and omega-6s. The omega numbers (3 or 6) refer to how many carbons away from the (methyl) end of the fatty acid chain the first carbon-carbon double bond appears.4 In regards to omega-3 fatty acids, the first carbon-carbon double bond is the third bond from the methyl end, while in omega-6 fatty acids, the first double bond is sixth from the end.1-3 The body can only form carbon-carbon double bonds after the ninth carbon from the methyl end of a fatty acid, which is ALA (which is later converted to EPA and DHA) is considered to be an essential fatty acid.6

This is important to note, as the double bond introduces a kink in the chain of carbons (hydrocarbon chain), which influences the structure and properties of the fatty acid molecules. These double bonds can influence how many hydrogen atoms can bind to the carbon atoms, meaning that the molecule is not as saturated with hydrogen atoms, thus making it an unsaturated fatty acid. EPA is considered to be a long chain omega-3 fatty acid because it contains 20 carbons, while DHA contains 22 carbons.

For context, monounsaturated fatty acids contain only one double bond (having less kinks, making them have higher oxidative stability), while polyunsaturated (poly meaning several or many) fatty acids contain more than one double bond, making them more susceptible to oxidation and highly reactive to light, heat and oxygen. This is often why we are told to not cook with oils (such as sunflower, corn, soybean, flax, grapeseed etc.), as they can be more chemically unstable and heat can produce more free radicals within these oils.4

While omega-6 fatty acids have received a great deal of negative attention in the past few years in the health world, it is salient to note that both omega-3s and omega-6s are essential for our health, and they both contribute to important physiological functions in the body. Along with omega-3s, omega-6 fatty acids play a critical role in brain functioning, growth and development, reproductive health and metabolic functioning. The caveat here is the balance between the two essential fatty acids, as research has found that excessive amounts of omega-6 fatty acids (relative to the amount of omega-3s) can lead to hyperactive immune response, alterations in inflammatory pathways and increased risk for developing cardiovascular and neurodegenerative diseases. Dietary changes over the past few years in regard to the intake of omega-6 vs. omega-3 shows an increase in the omega-6 to omega-3 ratio, which has led to an increase in chronic inflammatory diseases.1,4

Conversion of Omega-3s

Alpha-linolenic acid (ALA) is the “parent” or dietary precursor form for the long change omega-3 fatty acid; it is found in plants such as flaxseed and soybean oil. ALA is converted into EPA and DHA with the help of an enzyme known as delta-6 desaturase to form stearidonic acid (SDA). While some argue that they can get adequate levels of omega-3s in their diet from plant sources (such as ALA rich foods) the conversion rate of ALA to EPA and DHA in the body is rather low. Roughly only 8 percent of dietary ALA is converted to EPA, while 0-4 percent was converted to DHA. This low rate of conversion suggests that we should look to increase our consumption of animal based omega fatty acids (found in foods such as mackerel, caviar, salmon, sardines, oysters and sardines) or look to supplement with a quality omega-3 fish or krill oil to support healthy levels within the body.1,5

EPA vs. DHA

Omega-3s play an important structural role in our cell membranes and serve as precursors for lipid mediators. These mediators regulate inflammation, such as eicosanoids, prostaglandins, resolvins (metabolic by-products of omega-3 fatty acids that block the production of proinflammatory mediators and regulate clearance of neutrophils) and PPAR (which play a role on cell proliferation/differentiation and regulate gene expression). When omega fatty acids are incorporated into phospholipids (cell membranes), they can affect the fluidity, flexibility and permeability of cell membranes; studies have shown that increasing omega-3 fatty acid intake can increase the omega-3 content of red blood cells, immune cells, atherosclerotic plaque, cardiac tissues and other cells throughout the body.7

These omega-3s are found in different concentrations throughout the body and play different roles. DHA for example, is especially high in the retina, brain and sperm, while much of the research for EPA is around its ability to support healthy immune response, support healthy inflammatory pathways, and is used in the production of DHA in the body. EPA is mainly used to produce signaling molecules (eicosanoids) that contribute to inflammation, blood pressure regulation, fever and blood clotting.

Both EPA and DHA have neuro-protective effects. EPA and DHA have been found to support the production of dopamine, as well as increase neuronal growth in the frontal cortex of your brain (which deals with cognitive behavior, personality, decision making and planning) and increase cerebral circulation.11

DHA (which makes up more than 90 percent of omega fatty acids in the brain and up to 25 percent of its total fat content) has been shown to be supportive for memory and cognitive deficits and EPA can support healthy moods. DHA represents the main PUFA in the retina and neuronal cells (30-40 percent of the phospholipids in the gray matter of cerebral cortex and photoreceptor cells in the retina are made up of DHA). DHA is also essential to pre and postnatal brain development, where EPA seems to play more of a role in its ability to influence behavior and mood, both for the mother and the child.9,1,4

DHA is found in very high concentrations in the cell membranes of the retina, in fact the retina conserves and recycles DHA even when omega-3 levels are low. DHA also increases the release of acetylcholine, which can enhance memory, learning and synaptic plasticity (ability of the brain to change and adapt to new information) and is important for neurotransmitters.10

How Much Should I Take?

There are many factors that can contribute to an individual’s omega-3 status and how much they should take. Most of the clinical trials evaluating the effects of EPA+DHA suggest dose ranges between 250 mg to 1,000 mg per day, while research indicates that doses as large as 5,000 mg per day are safe for daily consumption by adults, but this is highly individual. There is no established upper limit of omega-3 intake and higher amounts may also be necessary when nursing or pregnant, or for individuals with metabolic risk factors.8 You can take a blood test (the omega-3 index) to assess and measure your omega-3 fatty acids if you want to determine personal and individual dietary recommendations. VR

References:

1 https://lpi.oregonstate.edu/mic/other-nutrients/essential-fatty-acids#introduction.

2 www.medicalnewstoday.com/articles/essential-fatty-acids#:~:text=Essential percent20fatty percent20acids percent20are percent20a, percent2D3 percent20and percent20omega percent2D6.

3 www.ncbi.nlm.nih.gov/pmc/articles/PMC6357022/.

4 www.ncbi.nlm.nih.gov/pmc/articles/PMC3335257/.

5 www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/stearidonic-acid.

6 https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/.

7 www.ncbi.nlm.nih.gov/pmc/articles/PMC3509649/.

8 www.medicalnewstoday.com/articles/324240#how-much-is-too-much.

9 https://pubmed.ncbi.nlm.nih.gov/18072818/.

10 www.ncbi.nlm.nih.gov/pmc/articles/PMC3206354/.

11 www.ncbi.nlm.nih.gov/pmc/articles/PMC6563911/.

Brianna Diorio holds a PhD in integrative medicine from the University of Natural Medicine and is a clinical nutritionist with a Master’s of Science in Human Nutrition from the University of Bridgeport. She is also a functional diagnostic nutrition practitioner (FDN), an herbal practitioner through the Herbal Academy, a family herbalist through The School of Natural Healing, a NASM certified personal trainer, and a holistic lifestyle coach from the C.H.E.K Institute. Diorio is the host of the Brianna Approved Podcast, which is a podcast for people who like a holistic approach to real science and clinical research on all things nutrition, botanicals and balance. She currently works as a clinician with her private practice that specializes in alternative health, functional medicine and dietary supplements. Diorio works with a vast array of clients and businesses to educate and improve their health and dietary needs.