Do you know your omega-3 from your omega-6?

We need both: but most of us are getting too much of one and not enough of the other. This imbalance has been linked to inflammation, chronic health conditions, pain conditions, behavioural disorders, and cognitive decline.^[1]

Both are necessary to our health, but they must be in the right balance.

 

What are omega-3 and omega-6 fatty acids?

Omega-3 and omega-6 are the two main types of polyunsaturated fatty acids (PUFAs) that our bodies require but cannot make, so they must be obtained from food or supplements.

The most common PUFAS in the diet are linoleic acid (LA, omega-6) and alpha-linolenic acid (ALA, omega-3). The body uses LA to make arachidonic acid (AA), and ALA to make omega-3 fats EPA and DHA, which are vital for normal function of the brain, heart, and immune system.

However, modern farming methods have led to decreases in omega-3 and increases in omega-6 in our diet.^[2] Omega-6 competes for the same enzyme, and can ‘block’ the conversion of omega-3 into EPA and DHA.^[3] High omega-6 intake shifts the balance toward arachidonic acid (AA) production, increasing the synthesis of pro-inflammatory eicosanoids.^[4] Over time, this imbalance of omega-6 can contribute to chronic health conditions such as cardiovascular disease, allergies, asthma, and arthritis.^[5]

 

Why do we need omega-3 fatty acids?

Brain and eye health

DHA is the main omega-3 fatty acid in the brain and retina. It plays a key role in vision and cognitive development, especially during pregnancy.^[6] Numerous studies show that DHA supports brain function, protects nerve cells, and helps regulate key neurotransmitters serotonin and acetylcholine. DHA is also required for foetal brain and eye development; supplementation during pregnancy may improve cognitive outcomes in children.^[7]

Mood and behaviour

Meta-analyses suggest that those with higher EPA + DHA intake are at lower risk of developing mood disorders such as depression.^[8] Studies involving high EPA supplementation (either alone or with DHA) appear to have positive results for depressive symptoms; taking DHA alone appears less effective.^[9]

Lower blood levels of EPA and DHA have been observed in children with ADHD and autism spectrum conditions; omega-3 supplementation is shown to improve clinical symptoms and cognitive performance.^[10]

Higher DHA intake is also associated with better memory and reduced risk of dementia.^[11]

 

Why do we need omega-6 fatty acids?

Skin health

Linoleic acid (LA) is a precursor for other omega-6 PUFAs. It is required for the fluidity and integrity of the skin barrier; a role that cannot be substituted by other fatty acids. An imbalance in eicosanoid production is implicated in chronic skin disorders such as atopic dermatitis and psoriasis.^[12]

 

Cholesterol and cardiovascular health

LA helps to lower total and LDL cholesterol by upregulating hepatic LDL receptors and increasing bile acid synthesis, as well as influencing LDL receptor activity.^[13] Higher intakes of LA have been associated with a reduced risk of cardiovascular disease and cancer mortality in several studies.^[14]

 

 

Omega-3 and omega-6: why the ratio matters

Maintaining a healthy balance of omega-3 and omega-6 is essential. While both are necessary, studies suggest that an omega-6 to omega-3 ratio of 2:1 or lower is ideal. Unfortunately, the standard Western diets skew heavily toward omega-6, with ratios ranging from 10:1 to 25:1.^[15]

Although individual needs may differ, consistently lower omega-6 to omega-3 ratios have been associated with reduced inflammation and improved outcomes across a range of health conditions.

In patients with heart disease, a ratio of 4:1 was found to reduce total mortality by 70%.^[16]  Patients with rheumatoid arthritis experienced reduced inflammation when taking a ratio of 2–3:1.^[17] Children with ADHD supplemented with a 9:3:1 ratio of EPA, DHA, and GLA showed significant improvement in behaviour, attention, and learning.^[18] Long-term omega-3 supplementation in older adults reduced the risk of developing Alzheimer’s by  64%.^[19]

Higher concentrations of omega-3 may also reduce the risk of obesity, relieve skin conditions such as dermatitis, and improve asthma control.^{[20],[21],[22]}

 

How to support an “optimal” ratio of omega-3 and omega-6

• Increase your intake of omega-3 rich foods. Good sources of omega-3 include oily fish (salmon, mackerel, sardines, trout) chia seeds, flaxseeds, walnuts, spirulina, and seaweeds.
• Reduce intake of omega-6 foods. These include vegetable oils (sunflower, safflower, soy, sesame, and corn oils), and processed snacks and fast foods that use these oils.
• Supplement with quality omega-3 fish oil. Look for a product with high EPA/DHA content sourced from cold water marine fish that has been independently tested for impurities.

 

This information is provided for educational purposes only and is not a substitute for professional medical advice. Always seek the guidance of your physician or qualified healthcare provider with any questions you may have regarding your health or a medical condition.

 

References

^[1] Sibille, K. T., King, C., Garrett, T. J., Glover, T. L., Zhang, H., Chen, H., Reddy, D., Goodin, B. R., Sotolongo, A., Petrov, M. E., Cruz-Almeida, Y., Herbert, M., Bartley, E. J., Edberg, J. C., Staud, R., Redden, D. T., Bradley, L. A., & Fillingim, R. B. (2018). Omega-6: Omega-3 PUFA Ratio, Pain, Functioning, and Distress in Adults With Knee Pain. The Clinical journal of pain, 34(2), 182–189. https://doi.org/10.1097/AJP.0000000000000517

^[2] Simopoulos A. P. (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 56(8), 365–379. https://doi.org/10.1016/s0753-3322(02)00253-6

^[3] DiNicolantonio, J. J., & O’Keefe, J. (2021). The Importance of Maintaining a Low Omega-6/Omega-3 Ratio for Reducing the Risk of Autoimmune Diseases, Asthma, and Allergies. Missouri medicine, 118(5), 453–459.

^[4] Simopoulos A. P. (2002). The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 56(8), 365–379. https://doi.org/10.1016/s0753-3322(02)00253-6

^[5] Mariamenatu, A. H., & Abdu, E. M. (2021). Overconsumption of Omega-6 Polyunsaturated Fatty Acids (PUFAs) versus Deficiency of Omega-3 PUFAs in Modern-Day Diets: The Disturbing Factor for Their “Balanced Antagonistic Metabolic Functions” in the Human Body. Journal of lipids, 2021, 8848161. https://doi.org/10.1155/2021/8848161

^[6] Calder P. C. (2016). Docosahexaenoic Acid. Annals of nutrition & metabolism, 69 Suppl 1, 7–21. https://doi.org/10.1159/000448262

^[7] Scientific Opinion on the essential composition of infant and follow-on formulae. (2014). EFSA Journal, 12(7), 3760. https://doi.org/10.2903/j.efsa.2014.3760

^[8] Grosso, G., Micek, A., Marventano, S., Castellano, S., Mistretta, A., Pajak, A., & Galvano, F. (2016). Dietary n-3 PUFA, fish consumption and depression: A systematic review and meta-analysis of observational studies. Journal of affective disorders, 205, 269–281. https://doi.org/10.1016/j.jad.2016.08.011

^[9] Liao, Y., Xie, B., Zhang, H., He, Q., Guo, L., Subramanieapillai, M., Fan, B., Lu, C., & McIntyre, R. S. (2019). Efficacy of omega-3 PUFAs in depression: A meta-analysis. Translational psychiatry, 9(1), 190. https://doi.org/10.1038/s41398-019-0515-5

^[10] Chang, JC., Su, KP., Mondelli, V. et al. Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder: a Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies. Neuropsychopharmacol. 43, 534–545 (2018). https://doi.org/10.1038/npp.2017.160

^[11] Yurko-Mauro, K., Alexander, D. D., & Van Elswyk, M. E. (2015). Docosahexaenoic acid and adult memory: a systematic review and meta-analysis. PloS one, 10(3), e0120391. https://doi.org/10.1371/journal.pone.0120391

^[12] Balić, A., Vlašić, D., Žužul, K., Marinović, B., & Bukvić Mokos, Z. (2020). Omega-3 Versus Omega-6 Polyunsaturated Fatty Acids in the Prevention and Treatment of Inflammatory Skin Diseases. International journal of molecular sciences, 21(3), 741. https://doi.org/10.3390/ijms21030741

^[13] Froyen, E., & Burns-Whitmore, B. (2020). The Effects of Linoleic Acid Consumption on Lipid Risk Markers for Cardiovascular Disease in Healthy Individuals: A Review of Human Intervention Trials. Nutrients, 12(8), 2329. https://doi.org/10.3390/nu12082329

^[14] Li, J., Guasch-Ferré, M., Li, Y., & Hu, F. B. (2020). Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies. The American journal of clinical nutrition, 112(1), 150–167. https://doi.org/10.1093/ajcn/nqz349

^[15] Brenna, J. T., & Diau, G. Y. (2007). The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition. Prostaglandins, leukotrienes, and essential fatty acids, 77(5-6), 247–250. https://doi.org/10.1016/j.plefa.2007.10.016

^[16] de Lorgeril, M., Renaud, S., Mamelle, N., Salen, P., Martin, J. L., Monjaud, I., Guidollet, J., Touboul, P., & Delaye, J. (1994). Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease. Lancet (London, England), 343(8911), 1454–1459. https://doi.org/10.1016/s0140-6736(94)92580-1

^[17] James, M. J., & Cleland, L. G. (1997). Dietary n-3 fatty acids and therapy for rheumatoid arthritis. Seminars in arthritis and rheumatism, 27(2), 85–97. https://doi.org/10.1016/s0049-0172(97)80009-1

^[18] 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

^[19] Wei, B. Z., Li, L., Dong, C. W., Tan, C. C., Alzheimer’s Disease Neuroimaging Initiative, & Xu, W. (2023). The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers. The American journal of clinical nutrition, 117(6), 1096–1109. https://doi.org/10.1016/j.ajcnut.2023.04.001

^[20] Balić, A., Vlašić, D., Žužul, K., Marinović, B., & Bukvić Mokos, Z. (2020). Omega-3 Versus Omega-6 Polyunsaturated Fatty Acids in the Prevention and Treatment of Inflammatory Skin Diseases. International journal of molecular sciences, 21(3), 741. https://doi.org/10.3390/ijms21030741

^[21] Wang, L., Manson, J. E., Rautiainen, S., Gaziano, J. M., Buring, J. E., Tsai, M. Y., & Sesso, H. D. (2016). A prospective study of erythrocyte polyunsaturated fatty acid, weight gain, and risk of becoming overweight or obese in middle-aged and older women. European journal of nutrition, 55(2), 687–697. https://doi.org/10.1007/s00394-015-0889-y

^[22] Stoodley, I., Garg, M., Scott, H., Macdonald-Wicks, L., Berthon, B., & Wood, L. (2019). Higher Omega-3 Index Is Associated with Better Asthma Control and Lower Medication Dose: A Cross-Sectional Study. Nutrients, 12(1), 74. https://doi.org/10.3390/nu12010074