Omega-3 Fatty Acids

Authored by Robert Chen • 
July 10, 2016
 • 4 min read

Take Home Points

  • The main subtypes of omega-3 fatty acids are eicosapentaenoic acid (EPA), docosahexaneoic acid (DHA), and α-linolenic acid (ALA).

  • Dietary supplementation with omega-3 fatty acids can yield benefits including improved memory, reduced symptoms of depression, decreases in triglyceride levels, and decreases in blood pressure.1

  • The ratios of DHA to EPA in various studies for cognition have ranged from 1-to-2 to 2-to-1. For example, several studies of omega-3 fatty acids on Alzheimer's disease have used blends of 1.7 g DHA and 0.7 g EPA daily as the intervention.2An optimal ratio has yet to be determined via rigorous scientific investigation.


Omega-3 fatty acids.


Omega-3 fatty acids are a class of polyunsaturated fatty acid compounds that have more than one double bond in their backbone.


Examples of omega-3 fatty acids include α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

The omega-3 fatty acids are important constituents of the cell membrane - the dynamic interface between cells and the rest of the body.

DHA Synapse

DHA is >30% of the lipid composition of the neural cell membrane. DHA helps promote fluidity at critical synaptic junctions - allowing dynamic molecular processes to take place


EPA and DHA are typically extracted from fish, while ALA is typically found in vegetable oil, nuts, flaxseed oils and grass-fed animal fats.

Effects on the Brain

Omega-3 fatty acids exhibit various beneficial effects on the brain.


Omega-3 fatty acids (blend of 1.6 g EPA and 0.8 g DHA, taken for a period of 55 days) led to improved sustained attention compared to placebo in healthy adults (measured by Zimmermann & Fimm Attention Test; mean decrease of 50 milliseconds in reaction time in a sustained attention task).3

Executive Function

Omega-3 fatty acids (1320 mg EPA + 880 mg DHA totalling 2.2 g, taken over 26 weeks) led to significantly improved executive function compared to placebo (p = 0.023), in elderly healthy adults (mean age 64, standard deviation 6.5). In particular, improvements in executive function increase nearly in lockstep with increases in EPA levels.4


Omega-3 fatty acids significantly improved performance on memory testing in children (780 school-aged children). In this study, omega-3 fatty acids were given in a blend also consisting of iron, zinc, folate, and vitamins A, B6, B12, C.5

Omega-3 fatty acids (1080 mg EPA and 720 mg DHA) catalyzed an improvement in the Clinician Interview-Based Impression of Change plus caregiver input (CIBIC-plus) evaluation for dementia patients (aged 55 to 90), when compared to placebo.6

Omega-3 fatty acid supplementation has been shown in various studies to correlate with decreased rates of Alzheimer's (a component of which is short-term and long-term memory loss), but the effects were not strongly statistically significant.7,8,9.


Deficiency of omega-3 fatty acids has been correlated with increased risk of depression.10,11

Deficiency of omega-3 fatty acids has been correlated with increased risk of bipolar disorder and schizophrenia.11,12

How to Take

For health, 250mg of EPA + DHA is the minimum dose (this can be obtained by eating a portion of oily fish). The American Heart Association recommends 1g daily. To reduce muscle soreness you can take higher amounts, up to 6 g per day.

Side Effects

No major side effects.

Extreme excess consumption of omega-3 fatty acids may lead to potentially negative cardiovascular effects.

Excess consumption of EPA may lead to up to 15% decrease in neutrophil activation, as shown in one study.13


Omega-3 fatty acids are FDA Generally Regarded As Safe products.

  1. Covington, M. B. (2004). Omega-3 fatty acids. Atlantic, 1, 2-0.

  2. Swanson, D., Block, R., & Mousa, S. A. (2012). Omega-3 fatty acids EPA and DHA: health benefits throughout life. Advances in Nutrition: An International Review Journal, 3(1), 1-7.

  3. Fontani, G., Corradeschi, F., Felici, A., Alfatti, F., Migliorini, S., & Lodi, L. (2005). Cognitive and physiological effects of Omega‐3 polyunsaturated fatty acid supplementation in healthy subjects. European journal of clinical investigation, 35(11), 691-699.

  4. Witte, A. V., Kerti, L., Hermannstädter, H. M., Fiebach, J. B., Schreiber, S. J., Schuchardt, J. P., ... & Flöel, A. (2013). Long-chain omega-3 fatty acids improve brain function and structure in older adults. Cerebral cortex, bht163.

  5. Osendarp, S. J., Baghurst, K. I., Bryan, J., Calvaresi, E., Hughes, D., Hussaini, M., . . . Wilson, C. (2007). Effect of a 12-mo micronutrient intervention on learning and memory in well-nourished and marginally nourished school-aged children: 2 parallel, randomized, placebo-controlled studies in Australia and Indonesia. Am J Clin Nutr, 86(4), 1082-1093.

  6. Chiu, C. C., Su, K. P., Cheng, T. C., Liu, H. C., Chang, C. J., Dewey, M. E., ... & Huang, S. Y. (2008). The effects of omega-3 fatty acids monotherapy in Alzheimer's disease and mild cognitive impairment: a preliminary randomized double-blind placebo-controlled study. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 32(6), 1538-1544.

  7. Morris, M. C., Evans, D. A., Bienias, J. L., Tangney, C. C., Bennett, D. A., Aggarwal, N., ... & Wilson, R. S. (2003). Dietary fats and the risk of incident Alzheimer disease. Archives of neurology, 60(2), 194-200.

  8. Barberger-Gateau, P., Letenneur, L., Deschamps, V., Pérès, K., Dartigues, J. F., & Renaud, S. (2002). Fish, meat, and risk of dementia: cohort study. Bmj, 325(7370), 932-933.

  9. Laurin, D., Verreault, R., Lindsay, J., Dewailly, É., & Holub, B. J. (2003). Omega-3 fatty acids and risk of cognitive impairment and dementia. Journal of Alzheimer's Disease, 5(4), 315-322.

  10. Adams, P. B., Lawson, S., Sanigorski, A., & Sinclair, A. J. (1996). Arachidonic acid to eicosapentaenoic acid ratio in blood correlates positively with clinical symptoms of depression. Lipids, 31 Suppl, S157-161.

  11. Freeman, M. P., Hibbeln, J. R., Wisner, K. L., Davis, J. M., Mischoulon, D., Peet, M., . . . Stoll, A. L. (2006). Omega-3 fatty acids: evidence basis for treatment and future research in psychiatry. J Clin Psychiatry, 67(12), 1954-1967.

  12. Peet, M., Laugharne, J. D., Mellor, J., & Ramchand, C. N. (1996). Essential fatty acid deficiency in erythrocyte membranes from chronic schizophrenic patients, and the clinical effects of dietary supplementation. Prostaglandins Leukot Essent Fatty Acids, 55(1-2), 71-75.

  13. Rees, D., Miles, E. A., Banerjee, T., Wells, S. J., Roynette, C. E., Wahle, K. W., & Calder, P. C. (2006). Dose-related effects of eicosapentaenoic acid on innate immune function in healthy humans: a comparison of young and older men. The American journal of clinical nutrition, 83(2), 331-342.

Editor's Choice
Emails worth reading.

Once a week, we'll send you the most compelling research, stories and updates from the world of human enhancement.