Omega-3: real benefits, sources and how to choose according to goals (EPA, DHA and ALA)

Want to understand omega-3 clearly and based on science?

In this article, you will understand what are they omega-3 fatty acids (EPA, DHA, and ALA), how they act in the body and what does the evidence in different key contexts: cardiovascular health, mental health, pregnancy and lactation, male fertility, and vegetarian or vegan diets. 

We will close with fonts dietary, plant-based alternatives such as algae oil, criteria quality when choosing a supplement and practical conclusions ...so you know when to prioritize EPA, DHA, or ALA depending on your goals and diet.

What is omega-3, how does it work, and what are its potential benefits?

The omega-3 they are a "good" type of fat that our body needs but does not produce in sufficient quantities, so we must obtain them from our diet. The most important are:

• EPA: ayuda a controlar la inflamación en el cuerpo. Está relacionado con beneficios en la salud del corazón y, en algunos estudios, con apoyo en problemas de ánimo como ansiedad o depresión.

• DHA: es un “ladrillo” esencial en la construcción del cerebro y la retina. Participa en la comunicación entre las neuronas y en la visión, y tiene un papel clave en el embarazo, la lactancia y la fertilidad masculina.

• ALA: se encuentra en alimentos vegetales como lino, chía o nueces. Nuestro cuerpo puede transformarlo en EPA y un poco en DHA, aunque esta conversión es limitada.

What does science say? What is it used for? 

Cardiovascular health

In people with high triglycerides on cholesterol medication help improve lipid profiles and reduce triglycerides, thus helping to maintain good cardiovascular health (Mozaffarian & Wu, 2011).

Mental health

Scientific reviews show that the effect of omega-3s on depression is modest yet realistic additional support, especialmente cuando el suplemento contiene más EPA que DHA.

modulation of inflammation and neuronal functionl, aunque los resultados clínicos siguen siendo moderados (Appleton et al., 2021; Su et al., 2018).

Pregnancy and breastfeeding

Increase the consumption of EPA and DHA during pregnancy can reduce the risk of premature birth, y por ello se recomienda que las gestantes y mujeres lactantes cubran bien sus necesidades de DHA (Middleton et al., 2018; Best et al., 2022). 

Male fertility

DHA is essential on sperm membranes. Men who consume more omega-3 have shown better semen quality in some studies, and reviews suggest improvements in sperm motility, although larger trials are still needed (Jensen et al., 2020; Hosseini et al., 2019)

Vegetarians and vegans

ALA, is present in foods such as flaxseed, chia, or walnuts. The body can convert it into EPA and, to a lesser extent, DHA, but this process is not very efficient.

The reason is that the conversion requires several enzymes that also participate in other fat metabolic pathways, meaning only a small portion of ALA is actually converted. In most people, this percentage is around 5%–10% for EPA and less than 1% for DHA (Burdge & Wootton, 2002; Brenna et al., 2009).

although a diet rich in ALA contributes to cardiovascular health, is usually not enough to cover the structural functions of DHA, essential for brain, vision, and fertility.

In vegetarians and vegans, a slight metabolic adaptation may occur: their bodies convert slightly more ALA into EPA, but DHA levels remain low (Rosell et al., 2005). Sanders (2009) confirms this trend and highlights that the algae oil is the most effective and direct way to meet DHA requirements without relying on animal sources (Arterburn et al., 2008).

What to look for when choosing a high-quality omega-3?

If you choose to take an omega-3 supplement, there are several aspects to keep in mind:

• Chemical form: los omega-3 pueden presentarse como triglicéridos naturales, etil ésteres o carboxilatos. Todas son formas válidas y absorbibles, pero los triglicéridos suelen mostrar una biodisponibilidad algo mayor.

• Actual EPA and DHA content: what matters is the exact amount of EPA and DHA per capsule, not the total milligrams of "fish oil" or "algae oil."

• Purity and contaminants: un omega-3 de calidad debe estar libre de metales pesados, dioxinas y PCB.

• Oxidation: fatty acids are highly sensitive; therefore, the product should incorporate natural antioxidants and be stored under appropriate conditions.

• Quality certifications: sellos como IFOS (International Fish Oil Standards) y IAOS (International Algal Oil Standards) y la organización GOED (Global Organization for EPA and DHA Omega-3s) garantizan pureza y trazabilidad.

Specific certifications in algae oils

In the case of plant-based omega-3, in addition to purity seals, you can find certifications that guarantee its vegan status and sustainability:

• V-Label: muy reconocido en Europa, avala que el producto es 100 % libre de ingredientes animales.

• The Vegan Society Trademark: sello británico con presencia internacional que certifica productos veganos en composición y procesado.

• Non-GMO Project Verified: guarantees the absence of genetically modified organisms, which are common in algae oils from the US.

• USP or NSF: certificaciones de laboratorios independientes que validan potencia, pureza y buenas prácticas de fabricación.

Conclusions

EPA, DHA and ALA comply distinct and complementary functions. EPA stands out for inflammation, cardiovascular risk, and anxiety-depressive symptoms; DHA is essential for the brain, vision, and male fertility; ALA contributes to cardiometabolic health, but does not cover the functions of DHA on its own.

En vegetarians and veganss metabolic adaptation slightly improves ALA conversion, but not enough algae oil constituye la mejor opción para garantizar niveles adecuados de DHA. 

Finally, it is very important to know how to choose a high-quality omega-3: it is advisable to look at the chemical form, the actual EPA and DHA content, the purity, the protection against oxidation, and the presence of reliable certifications that guarantee its safety and sustainability.

consult with a professional health who can guide you in your particular case.

References

1. Appleton KM, Voyias PD, Sallis HM, Dawson S, Ness AR, Churchill R, Perry R. Omega-3 fatty acids for depression in adults. Cochrane Database Syst Rev. 2021 Nov 24;11(11):CD004692. doi: 10.1002/14651858.CD004692.pub5. PMID: 34817851; PMCID: PMC8612309.

2. Arterburn LM, Oken HA, Bailey Hall E, Hamersley J, Kuratko CN, Hoffman JP. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of docosahexaenoic acid. J Am Diet Assoc. 2008 Jul;108(7):1204-9. doi: 10.1016/j.jada.2008.04.020. PMID: 18589030.

3. Best KP, Gold M, Kennedy D, Martin J, Makrides M. Omega-3 long-chain PUFA intake during pregnancy and allergic disease outcomes in the offspring: a systematic review and meta-analysis of observational studies and randomized controlled trials. Am J Clin Nutr. 2016 Jan;103(1):128-43. doi: 10.3945/ajcn.115.111104. Epub 2015 Dec 16. PMID: 26675770.

4. Bhatt DL, Steg PG, Miller M, Brinton EA, Jacobson TA, Ketchum SB, Doyle RT Jr, Juliano RA, Jiao L, Granowitz C, Tardif JC, Ballantyne CM; REDUCE-IT Investigators. Cardiovascular Risk Reduction with Icosapent Ethyl for Hypertriglyceridemia. N Engl J Med. 2019 Jan 3;380(1):11-22. doi: 10.1056/NEJMoa1812792. Epub 2018 Nov 10. PMID: 30415628.

5. Brenna JT, Salem N Jr, Sinclair AJ, Cunnane SC; International Society for the Study of Fatty Acids and Lipids, ISSFAL. alpha-Linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans. Prostaglandins Leukot Essent Fatty Acids. 2009 Feb-Mar;80(2-3):85-91. doi: 10.1016/j.plefa.2009.01.004. Epub 2009 Mar 9. PMID: 19269799.

6. Burdge GC, Wootton SA. Conversion of alpha-linolenic acid to eicosapentaenoic, docosapentaenoic and docosahexaenoic acids in young women. Br J Nutr. 2002 Oct;88(4):411-20. doi: 10.1079/BJN2002689. PMID: 12323090.

7. Hosseini B, Nourmohamadi M, Hajipour S, Taghizadeh M, Asemi Z, Keshavarz SA, Jafarnejad S. The Effect of Omega-3 Fatty Acids, EPA, and/or DHA on Male Infertility: A Systematic Review and Meta-analysis. J Diet Suppl. 2019;16(2):245-256. doi: 10.1080/19390211.2018.1431753. Epub 2018 Feb 16. PMID: 29451828.

8. Innis SM. Dietary (n-3) fatty acids and brain development. J Nutr. 2007 Apr;137(4):855-9. doi: 10.1093/jn/137.4.855. PMID: 17374644.

9. Jensen TK, Priskorn L, Holmboe SA, Nassan FL, Andersson AM, Dalgård C, Petersen JH, Chavarro JE, Jørgensen N. Associations of Fish Oil Supplement Use With Testicular Function in Young Men. JAMA Netw Open. 2020 Jan 3;3(1):e1919462. doi: 10.1001/jamanetworkopen.2019.19462. PMID: 31951274; PMCID: PMC6991322.

10. Middleton P, Gomersall JC, Gould JF, Shepherd E, Olsen SF, Makrides M. Omega-3 fatty acid addition during pregnancy. Cochrane Database Syst Rev. 2018 Nov 15;11(11):CD003402. doi: 10.1002/14651858.CD003402.pub3. PMID: 30480773; PMCID: PMC6516961.

11. Mozaffarian D, Wu JH. Omega-3 fatty acids and cardiovascular disease: effects on risk factors, molecular pathways, and clinical events. J Am Coll Cardiol. 2011 Nov 8;58(20):2047-67. doi: 10.1016/j.jacc.2011.06.063. PMID: 22051327.

12. Rosell MS, Lloyd-Wright Z, Appleby PN, Sanders TA, Allen NE, Key TJ. Long-chain n-3 polyunsaturated fatty acids in plasma in British meat-eating, vegetarian, and vegan men. Am J Clin Nutr. 2005 Aug;82(2):327-34. doi: 10.1093/ajcn.82.2.327. PMID: 16087975.

13. Sanders TA. DHA status of vegetarians. Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):137-41. doi: 10.1016/j.plefa.2009.05.013. Epub 2009 Jun 4. PMID: 19500961.

14. Su KP, Tseng PT, Lin PY, Okubo R, Chen TY, Chen YW, Matsuoka YJ. Association of Use of Omega-3 Polyunsaturated Fatty Acids With Changes in Severity of Anxiety Symptoms: A Systematic Review and Meta-analysis. JAMA Netw Open. 2018 Sep 7;1(5):e182327. doi: 10.1001/jamanetworkopen.2018.2327. PMID: 30646157; PMCID: PMC6324500.