You’ve probably heard that DHA, EPA, and omega-3 are important for good health and wellbeing. But what are they exactly? How does one differ from another? Which do you really need?

Here’s a quick overview of how these valuable nutrients work.

 

What are omega-3 fatty acids?

Fatty acids are generally divided into two groups: saturated and unsaturated fatty acids. Unsaturated fatty acids have one or more double bonds between carbon atoms, while saturated fatty acids have no double bond. A double bond creates a “bend” in the molecule, which makes it more fluid and flexible.^[1] This flexibility helps fatty acids integrate into cell membranes in the brain and heart, supporting their structure and function.

Saturated fats have no bend and are solid at room temperature, which can impair the function of cells including their ability to clear cholesterol, and may also contribute to increased inflammation.^[2]

Omega-3 fatty acids are referred to as polyunsaturated fatty acids (PUFAs) because they have more than one double bond, while monounsaturated fats have one double bond.
The most readily available PUFAs are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). These two fatty acids have a wide range of health benefits – as we’ll explain here.

 

Docosahexaenoic acid (DHA): Vision and cognition

DHA plays critical roles in all stages of life, from fetal development to elderly cognitive function.

DHA has a longer carbon chain and more double bonds than EPA, which makes it even more unsaturated. It is more concentrated in the brain and eyes than EPA, comprising around 97% and 93% of the omega-3 fatty acids in these organs, and has greater influence on these tissues.^[3]

 

Benefits of DHA^[4],[5]

• Essential for neural tissue and membrane structure, including synaptic terminals (the ‘sending station’ for signals between neurons)
• Precursor to several bioactive metabolites including those involved in the resolution phase of inflammation
• Regulates the central nervous system by supporting neuronal membrane structure, enhancing synaptic plasticity, and balancing neurotransmitters such as dopamine and serotonin.
• Enhances membrane fluidity, neuronal differentiation, and growth
• Essential for fetal and infant brain and eye development
• Helps prevent preterm delivery
• Reduces the risk of cardiovascular disease
• Supports healthy cognitive function throughout adulthood
• Supports eye health across all ages
• May play a role in supporting healthy gut microbiota

 

Eicosapentaenoic Acid (EPA): Heart and circulation

Like DHA, EPA’s unique structure has important benefits. It can change the composition of cell membranes by replacing arachidonic acid, an omega-6 fat, which may influence various biological processes.^[6] The breakdown of EPA generates valuable antithrombotic and anti-inflammatory lipid mediators, as opposed to the prothrombotic and pro-inflammatory factors produced by arachidonic acid.^[7] These benefits have been observed with EPA either when taken alone or alongside statins.^[8]

Benefits of EPA^[9],[10]

• Lowers triglyceride and cholesterol levels by blocking production of very-low-density lipoprotein (the primary carrier of triglycerides)
• Protects cells against oxidative damage and reduces neuronal cell death
• Supports endothelium function and reduces plaque buildup in the arteries by reducing foam cell formation
• Forms anti-inflammatory nanomolecules called resolvins around the body
• Enhances antioxidant and anti-inflammatory functions of high-density lipoproteins
• Helps remove excess cholesterol from immune cells and lowers blood pressure by improving endothelial function
• Improves focus and attention in children with ADHD, particularly those with low EPA levels.
• Supports memory and learning by becoming a vital component of brain cell membranes, facilitating communication between neurons, and reducing inflammation in the brain
• May improve blood flow to the prefrontal cortex, the area involved in executive functions such as planning and decision-making.
• Improves mood disorders by reducing inflammation in the brain and increasing the expression of neurotrophins, as well as improving membrane fluidity and the binding of neurotransmitters

 

Which omega-3 is best for you?

Memory function, learning, and overall brain health: DHA

Mood, attention span, and mental health: EPA

Foetal development, healthy pregnancy, infant brain health: EPA & DHA

Cardiovascular health: EPA

Vegetarians and vegans: Algae-based DHA

 

Good sources of DHA and EPA

Dietary sources of omega-3 fatty acids include oily, cold-water fish, such as salmon, mackerel, sardines, herring, canned light tuna, and shellfish. Krill oil and algal oil are also excellent sources of DHA.

Omega-3 supplements are widely available, but it’s important to note that not all supplements are the same. Evidence suggests the bioavailability of EPA and DHA depends on the source and processing of the oil. Emulsified fish oils are a concentrated form of oil that improves the digestion and absorption of EPA and DHA, while purification reduces mercury contamination.^[11]

It’s also been found that DHA in phospholipid and triglyceride forms is more readily absorbed by the body than those in ethyl ester form (a synthetic form of fish oil).^[12]

 

The importance of DHA-to-EPA ratios

Research has suggested that different ratios of DHA:EPA can have different benefits.

For example, a 1:2 DHA/EPA ratio has been found most effective at alleviating liver damage and inflammatory risk factors, while a higher EPA content (such as 2:1) is linked to improved focus in children with ADHD.^[13],[14]  A large meta-analysis also found that combining  EPA and DHA with GLA (an omega-6 fatty acid) in a 9:3:1 ratio was most effective in improving ADHD symptoms.^[15]

Dosages of 2 g/day EPA is most effective in patients with severe mood disorders.^[16]

Both DHA and EPA are essential for health, but it’s helpful to know how each of these incredible nutrients support your wellbeing. Choosing the right balance based on your needs – whether for brain function, mood, or cardiovascular health – can provide lifelong benefits.

 

This content is for educational purposes only and is not a substitute for health professional advice.

 

^[1] Roche H. M. (1999). Unsaturated fatty acids. The Proceedings of the Nutrition Society, 58(2), 397–401. https://doi.org/10.1017/s002966519900052x

^[2] Linton MRF, Yancey PG, Davies SS, et al. The Role of Lipids and Lipoproteins in Atherosclerosis. [Updated 2019 Jan 3]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK343489

^[3] Li, J., Pora, B. L. R., Dong, K., & Hasjim, J. (2021). Health benefits of docosahexaenoic acid and its bioavailability: A review. Food science & nutrition, 9(9), 5229–5243. https://doi.org/10.1002/fsn3.2299

^[4] Li, J., Pora, B. L. R., Dong, K., & Hasjim, J. (2021). Health benefits of docosahexaenoic acid and its bioavailability: A review. Food science & nutrition, 9(9), 5229–5243. https://doi.org/10.1002/fsn3.2299

^[5] Lauritzen, L., Brambilla, P., Mazzocchi, A., Harsløf, L. B., Ciappolino, V., & Agostoni, C. (2016). DHA Effects in Brain Development and Function. Nutrients, 8(1), 6. https://doi.org/10.3390/nu8010006

^[6] Crupi, R., & Cuzzocrea, S. (2022). Role of EPA in Inflammation: Mechanisms, Effects, and Clinical Relevance. Biomolecules, 12(2), 242. https://doi.org/10.3390/biom12020242

^[7] Weintraub H. S. (2014). Overview of prescription omega-3 fatty acid products for hypertriglyceridemia. Postgraduate medicine, 126(7), 7–18. https://doi.org/10.3810/pgm.2014.11.2828

^[8] Mozaffarian, D., & Wu, J. H. (2011). Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events. Journal of the American College of Cardiology, 58(20), 2047–2067. https://doi.org/10.1016/j.jacc.2011.06.063

^[9] Dighriri, I. M., Alsubaie, A. M., Hakami, F. M., Hamithi, D. M., Alshekh, M. M., Khobrani, F. A., Dalak, F. E., Hakami, A. A., Alsueaadi, E. H., Alsaawi, L. S., Alshammari, S. F., Alqahtani, A. S., Alawi, I. A., Aljuaid, A. A., & Tawhari, M. Q. (2022). Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review. Cureus, 14(10), e30091. https://doi.org/10.7759/cureus.30091

^[10] Kaur, N., Chugh, V., & Gupta, A. K. (2014). Essential fatty acids as functional components of foods- a review. Journal of food science and technology, 51(10), 2289–2303. https://doi.org/10.1007/s13197-012-0677-0

^[11] Garaiova, I., Guschina, I. A., Plummer, S. F., Tang, J., Wang, D., & Plummer, N. T. (2007). A randomised cross-over trial in healthy adults indicating improved absorption of omega-3 fatty acids by pre-emulsification. Nutrition journal, 6, 4. https://doi.org/10.1186/1475-2891-6-4

^[12] Davidson, M. H., Johnson, J., Rooney, M. W., Kyle, M. L., & Kling, D. F. (2012). A novel omega-3 free fatty acid formulation has dramatically improved bioavailability during a low-fat diet compared with omega-3-acid ethyl esters: the ECLIPSE (Epanova(®) compared to Lovaza(®) in a pharmacokinetic single-dose evaluation) study. Journal of clinical lipidology, 6(6), 573–584. https://doi.org/10.1016/j.jacl.2012.01.002

^[13] Shang, T., Liu, L., Zhou, J., Zhang, M., Hu, Q., Fang, M., Wu, Y., Yao, P., & Gong, Z. (2017). Protective effects of various ratios of DHA/EPA supplementation on high-fat diet-induced liver damage in mice. Lipids in health and disease, 16(1), 65. https://doi.org/10.1186/s12944-017-0461-2

^[14] Pei-Chen Chang J. (2021). Personalised medicine in child and Adolescent Psychiatry: Focus on omega-3 polyunsaturated fatty acids and ADHD. Brain, behavior, & immunity – health, 16, 100310. https://doi.org/10.1016/j.bbih.2021.100310

^[15] D’Helft, J., Caccialanza, R., Derbyshire, E., & Maes, M. (2022). Relevance of ω-6 GLA Added to ω-3 PUFAs Supplements for ADHD: A Narrative Review. Nutrients, 14(16), 3273. https://doi.org/10.3390/nu14163273

^[16] Peet, M., Horrobin, D. F., & E-E Multicentre Study Group (2002). A dose-ranging exploratory study of the effects of ethyl-eicosapentaenoate in patients with persistent schizophrenic symptoms. Journal of psychiatric research, 36(1), 7–18. https://doi.org/10.1016/s0022-3956(01)00048-6