Omega-3 Fatty Acids for Brain Health

by Danny Parr, M.S. CandidateNutrition
Woman's hands slicing a salmon filet.

What are Omega-3 Fatty Acids?

Omega-3 fatty acids are a type of polyunsaturated fatty acid (PUFA) that are an important component of cell membranes and are used to form eicosanoids, signaling molecules involved in inflammation, blood pressure, and more. [1] 

There are three main types of omega-3 fatty acids: 

  • Alpha-linolenic acid (ALA)
  • Eicosapentaenoic acid (EPA)
  • Docosahexaenoic acid (DHA) 

ALA can be found in plant oils such as flaxseed, soybean, and canola oils and is considered essential, meaning it must come from the diet. ALA can be converted into EPA and DHA, but the conversion is very limited. [1] It is recommended to consume EPA and DHA directly from foods and/or dietary supplements.

Why are Omega-3s Important for Brain Health?

Based on evidence from observational studies, researchers believe that omega-3s may protect cognitive function by helping to maintain neuronal function and cell membrane integrity in the brain. An association has been found between fish intake and lower risks of dementia and Alzheimer’s disease. [2] The intake of omega-3s is also associated with a 20% lower risk of dementia or cognitive decline, particularly for DHA intake. [3] A 2022 review of randomized clinical trials looking at omega-3s and brain function found higher cognitive performance with EPA supplementation. [4] The research shows that omega-3 supplementation seems to slow cognitive decline rather than produce improvements. [5]

Meeting Omega-3 Needs

While experts have not determined the required amount of all 3 omega-3s, the average daily recommended amounts for ALA are 1.6 g for men and 1.1 g for women. [1] Some foods that contain higher amounts of omega-3s are: 

  • Fish and other seafood (especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines)
  • Nuts and seeds (such as flaxseed, chia seeds, and walnuts)
  • Plant oils (such as flaxseed oil, soybean oil, and canola oil)
  • Fortified foods (such as certain brands of eggs, yogurt, juices, milk, soy beverages, and infant formulas)

Omega-3 Supplementation

Some of the omega 3 supplements available include:

  • Fish oil supplements contain EPA and DHA.
  • Fish liver oil supplements, such as cod liver oil, contain EPA and DHA.
  • Krill oil contains omega-3s in the form of phospholipids.
  • Algal oils are a vegetarian source of DHA; some also contain EPA.
  • Flaxseed oil contains ALA.

As with any supplement, be sure to talk to your healthcare provider or registered dietitian before implementing it into your routine. Side effects of omega-3 supplements are usually mild and can include unpleasant taste, bad breath, bad-smelling sweat, headache, and gastrointestinal symptoms such as heartburn, nausea, and diarrhea. [6]

According to the FDA, omega-3 supplements that provide no more than 5 g/day of EPA and DHA are safe to use. [7]

References

  1. Omega-3 Fatty Acids, 2024: https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
  2. Zhang et al, 2016: https://doi.org/10.3945/ajcn.115.124081
  3. Dighriri et al: https://doi.org/10.7759/cureus.30091
  4. Wei et al, 2023: https://doi.org/10.1016/j.ajcnut.2023.04.001
  5. Sherzai et al, 2022: https://doi.org/10.1177/15598276221117102
  6. Hopp et al, 2024: https://www.nccih.nih.gov/health/omega3-supplements-what-you-need-to-know
  7. US FDA, 2029: https://www.fda.gov/media/128043/download