The Brain Benefits of Omega-3 Fats

Omega-3s help mood, memory and many brain health issues, but most of us are deficient. Learn to use foods and supplements for a healthy omega-3 to 6 ratio.

The discovery of the importance of essential fatty acids (EFAs) has been hailed as one of the most significant health advances in modern nutrition.

The omega-3 essential fatty acids in particular are one of the most beneficial groups of nutrients for your brain and overall health.

Omega-3s lower your risk of major chronic diseases including heart disease, cancer, and arthritis. (1)

They can also improve your mood and memory and protect your brain against disorders ranging from depression to dementia.

But deficiency is widespread — it’s estimated that 70% of Americans have insufficient levels of omega-3. (2)

Omega-3 deficiency is linked to over 50 diseases and contributes to 96,000 preventable deaths per year. (34)

There’s no doubt that you need omega-3s, but there is a lot of confusion about how to get them from both foods and supplements.

The Top Omega-3 Benefits for Mental Health

Omega-3s are considered essential fatty acids because your body can’t make them — you have to get them in your diet.

The list of diseases and disorders they’ve been found to help is a long one that includes heart disease, rheumatoid arthritis, diabetes, osteoporosis, and various kinds of cancer. (5)

Omega-3s are found in high concentrations in the nervous system and the brain where they are needed to build healthy cell membranes, reduce inflammation, promote new cell formation, form important brain chemicals, and improve nerve transmission. (6)

There are two main omega-3 fatty acids — EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

DHA is unarguably the most important omega-3 for brain health, accounting for 97% of the omega-3 fatty acids found in the brain. (7)

DHA is a critical structural component of the cerebral cortex, the area of the brain responsible for memory, language, abstraction, creativity, judgment, emotion and attention.

It is such an important building block that people with low levels of it actually have measurably smaller brains! (8)

DHA also supports optimal levels of neurotransmitters including dopamine, serotonin, GABA, and acetylcholine. (9)

Now, let’s take a look at research that reveals the benefits of omega-3s for specific mental health issues and brain functions.

Anxiety and Depression

Low levels of omega-3 have been linked to anxiety, depression, and bipolar disorder. (10)

Medical students facing pre-exam stress exhibited a 20% reduction in anxiety when taking omega-3 supplements. (11)

A review of studies in people with mood disorders found that omega-3s have significant antidepressant properties. (12)

One study found that omega-3 supplements are effective, fast-acting antidepressants.

After only three weeks of supplementation, an impressive 67% of study participants no longer met the criteria for being depressed. (13)

Omega-3s have been found helpful for major depressive disorder. (14)

So far, the data suggests that EPA is more effective for treating mild to moderate depression than DHA. (15)

Eight weeks of EPA supplementation was shown to be as effective as the popular prescription antidepressant fluoxetine (Prozac) for treating major depressive disorder. (16)

And when EPA was taken along with fluoxetine, the results were significantly better than either fluoxetine or EPA alone.

Attention deficit hyperactivity disorder (ADHD)

Children and adolescents with ADHD have lower blood levels of omega-3s, suggesting that supplementation could be helpful. (1718)

A systematic review of 52 studies on children with ADHD found that fish oil supplementation and elimination diets are the most promising dietary interventions for ADHD. (19)

One study found that students given omega-3 supplements did better in reading and spelling, were better behaved, and showed a reduction in overall ADHD symptoms.(20)

Another study gave children large doses of omega-3s (up to 16 grams per day) and found that supplements were well tolerated and resulted in significant improvements in inattention, hyperactivity, and defiant behavior. (21)

If you are treating a child with ADHD with omega-3 supplements, be patient.

It can take quite a while for maximum benefits to kick in. (22)

One study found that no real changes occurred after 3 months, but by 6 months significant improvements were noted in restlessness, aggressiveness, academic performance, inattention, impulsiveness, and cooperation with adults.

Autism Spectrum Disorder (ASD)

Omega-3 fatty acids show promise for treating autism. (23)

One study found that when autistic children were given omega-3 supplements, they showed marked improvements in hyperactivity and repetitive behaviors. (24)

However, a major meta analysis of 143 studies determined that there is currently insufficient scientific evidence to determine if omega-3 fatty acids are safe or effective for autistic spectrum disorder.

But researchers concluded that this was largely due to the poor quality of the studies and noted that more high-quality studies are needed.

Brain Development in Children

Omega-3s are essential for both new moms and their babies.

Postpartum depression affects 15% of all new moms.

When new mothers struggling with postpartum depression were given omega-3 supplements they showed at least a 50% reduction in symptoms according to two standard depression scales. (25)

Omega-3s are crucial for brain and nervous system development in infants and children. (26, 27)

Getting enough omega-3s during pregnancy has been associated with numerous benefits for the child, including reduced risk of cerebral palsy, autism spectrum disorder, and attention deficit/hyperactivity disorder. (28)

Brain Injuries

According to emerging science and clinical experience, aggressive intake of omega-3 fatty acids may be beneficial for brain injuries. (29)

Dr. Michael D. Lewis is a leading expert on nutritional interventions for brain health, particularly the use of omega-3 fatty acids for the prevention, management, and rehabilitation of concussions and traumatic brain injury (TBI).

He founded Brain Health Education and Research Institute, a nonprofit organization, and is the author of When Brains Collide: What Every Athlete and Parent Should Know About the Prevention and Treatment of Concussions and Head Injuries.

He has treated brain injury patients with large quantities of omega-3s with impressive results.

You can see his Omega-3 Protocol for Brain Injury here.

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Cognitive Decline and Memory Loss

Omega-3 fatty acids shield against age-related mental decline and can aid learning and memory in adults of all ages. (30, 3132)

A lack of omega-3s can cause your brain to age faster and measurably shrink. (33, 34)

Numerous studies support that seniors with higher levels of omega-3s, specifically DHA, have a significantly lower risk of developing dementia or Alzheimer’s. (35, 363738)

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It seems there are benefits to getting some omega-3s from your diet instead of relying totally on supplements.

Surprisingly, simply eating fish once a week increases the amount of gray matter in the brain. (39)

A diet high in fish, omega-3 oils, fruit, and vegetables reduces the risk of dementia and Alzheimer’s. (40)

Learn more —
DHA Supplements: Why They’re Critical for Your Brain

Psychiatric Disorders

Many major psychiatric disorders have been linked to omega-3 deficiency.

Research confirms that the following disorders can benefit from omega-3 supplementation: major depressive disorder, suicidal behavior, bipolar disorder, psychosis, schizophrenia, and borderline personality disorder. (41, 42, 43, 4445)

Military suicides have been linked to a lack of omega-3s.

Veterans with low blood levels of DHA are 62% more likely to commit suicide than those with the highest levels. (46)

Surprisingly, a low DHA level is a stronger predictor of suicide than battle-related stress.

A Core Omega-3 Benefit: Reduced Inflammation

You might be wondering how omega-3s can alleviate so many different kinds of conditions.

One of the main ways omega-3s work is by effectively curbing chronic inflammation.

Chronic inflammation is a contributing factor in most major diseases including allergies, heart disease, chronic obstructive pulmonary disease, osteoporosis, autoimmune diseases, cancer, diabetes, digestive diseases, and Alzheimer’s disease. (47, 48, 49)

But there’s another group of essential fatty acids that you need to know about that fuel inflammation — the omega-6 fatty acids.

Learn more —
Brain Inflammation May Be the Cause of Your Depression

The Ideal Omega-3 to Omega-6 Ratio

We need some omega-6s in our diet, but most of us consume way more than is healthy.

Our distant ancestors ate a 1-1 ratio of omega-6s to omega-3s. (50)

Ideally, we should be eating at most 2-4 times more omega-6 than omega-3 fats.

A diet with a 10-to-1 ratio is considered detrimental to health. (51)

But the average American eats an alarming 25 times more omega-6 than omega-3 fats! (52)

The major source of omega-6 fats in our diet is from supposedly healthy vegetable oils like canola, safflower, and soy oils.

Learn more —
8 Ways Canola Oil Is Bad for Brain Health

The Mediterranean diet, on the other hand, which is widely considered the healthiest diet of all, has a healthy balance between omega-3 and omega-6 fatty acids.

There is still some debate as to which is more important — the ratio of omega-6 to omega-3 or the absolute intake of omega-3s.

But either way, the experts agree.

We are eating far too much omega-6 and not enough omega-3 fats. (53)

The Best Omega-3 Food Sources and Why Quality Matters

I could simply give you a list of foods high in omega-3s, but getting your omega-3s from food is not that simple.

There are a lot of variables to consider in trying to get your omega-3 fat requirement from food.

How much omega-3 you can obtain from food depends on numerous factors, including the quality of the food source and the omega-3 form that occurs in a food.

(Don’t stress trying to remember the details that follow. There’s a concise summary at the end of this article.)

Plant vs Animal Food Sources of Omega-3s

The first big-picture item to consider is whether you should get your omega-3s from plant or animal food sources.

Omega-3 fats are found in both plants and animals, but each contains different forms of omega-3.

Animal sources are high in health-promoting EPA and DHA.

Plants, on the other hand, contain ALA (alpha-linolenic acid).

ALA gets converted in the body to EPA and DHA, but not very well.

In fact, a minuscule amount gets converted.

Less than 5% of ALA gets converted to EPA and less than 0.5% is converted to DHA. (54)

The Best Land Animal Sources of Omega-3

Meat, poultry and eggs can be good sources of omega-3 depending on how the animals are raised.

Just like us, animals can’t manufacture omega-3 fats; they get them from the food they eat.

Until fairly recently, domesticated animals spent their lives grazing on wild grasses and other natural omega-3 food sources.

But now, most cattle spend their days in feedlots eating mostly corn and other grains — foods that don’t contain omega-3s. (55)

This major change in our food supply is largely responsible for our current epidemic of omega-3 deficiency.

Grass-fed beef and bison, pasture-fed pork and lamb, and free range chicken and their eggs contain significantly more omega-3s than their mass-produced counterparts. (56)

And, of course, wild game is still an excellent source of omega-3s. (57)

The Best Fish Sources of Omega-3 Fats

Fish is sometimes referred to as “brain food” largely due to its high omega-3 content.

But there are many concerns about high levels of mercury, PCBs, pesticides, and other contaminants found in fish.

Fortunately, there are a handful of fish that are high in omega-3s and low in mercury — Alaskan salmon, herring, mackerel, and sardines. (58)

omega-3 benefits

Omega-3 Benefits vs Risks of Eating Fish

Do the benefits of the omega-3s found in fish outweigh the risks of eating them?

Let’s look at the case of salmon, the most popular cold water fish.

Most salmon you’ll find in the supermarket is farm-raised, regardless of how it’s labeled.

According to the Environmental Defense Fund (EDF), a consumer watchdog group, most salmon sold in the US is farm-raised then incorrectly labeled “Atlantic salmon.” (59)

The EDF recommends eating only Alaskan wild salmon, either fresh or canned, since it is low in contaminants and high in omega-3s. (60)

Wild salmon contains fewer contaminants than farm-raised and no antibiotics. (61)

There are some big problems with farm-raised salmon.

Since the production of one pound of farmed salmon requires over six pounds of fish, contaminants accumulate. (62)

Farmed salmon has more fat than wild salmon and, unfortunately, a large part of these fats are the unhealthy omega-6 kind. (63)

The trend is for fish farms to replace fish oil in fish feed with less expensive vegetable oil, so you can expect a worse omega-6 to omega-3 ratio. (64)

Farmed salmon was found to contain high concentrations of dioxins and pesticides and alarmingly more PCBs than any other protein source. (65)

The chart below compares omega-3 content to the levels of mercury found in various kinds of seafood.

Seafood in the upper right hand corner is the healthiest by these two measures.

seafood omega-3 vs mercury chart

Image courtesy of

The information used to compile this infographic comes from a Report of the Joint FAO/WHO Expert Consultation on the Risks and Benefits of Fish Consumption issued by the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO).

So, at least for now, the omega-3 benefits of moderate fish consumption (1-2 times per week) can outweigh the risks, especially if you stick with wild-caught, cold water fish. (66)

Learn more —
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The Best Plant Food Sources of Omega-3

ALA (alpha-linolenic acid) is the omega-3 found in plant foods.

The best food sources of ALA include flax seeds, chia seeds, pumpkin seeds, hemp seeds, walnuts, and soybeans. (67)

Nut and seed oils such as flaxseed oil, canola oil, soybean oil, pumpkin seed oil, and walnut oil also contain ALA.

But these oils are also high in inflammatory omega-6 fats.

You can see in the chart below how the presence of ALA omega-3s (in orange) is accompanied by large amounts of omega-6s (in blue).

Poor ALA conversion into omega-3 fats, plus the presence of omega-6 fats, makes even the best plants poor sources of omega-3s.

vegetable oil chart

Image courtesy of

How to Choose an Omega-3 Supplement

If you’re thinking that it’s hard to get the omega-3 fatty acids you need just from food, you’re absolutely right.

There is little doubt that this is why an estimated 70% of the US population is low in omega-3s. (68)

For most of us, supplementation is the answer.

There are a few popular sources of omega-3 supplements — fish oil, krill oil, flaxseed oil, and algal oil.

Fish Oil — The Original Omega-3 Supplement

Fish oil is one of the most popular nutritional supplements and one of the most widely studied.

Americans spend $2.6 billion yearly on it. (69)

The National Institutes of Health lists over 20,000 published studies on it.

Proven brain health benefits of fish oil include improvements in: (70)

  • ADHD
  • aggression
  • anxiety
  • bipolar disorder
  • cognition in the elderly
  • dementia (decreased risk)
  • depression
  • memory
  • mental processing accuracy
  • mood and general well-being
  • reaction time
  • stress
  • stroke (both preventative and therapeutic)

Other proven health benefits of fish oil include decreased inflammation and associated pain of rheumatoid arthritis, normalized triglyceride, cholesterol, and blood pressure levels, increased bone density, and reduced risk of heart disease, cancer, macular degeneration, and diabetes. (71, 72)

Learn more —
Fish Oil: Liquid Gold for Depression and Mood Disorders

Krill Oil — Possibly Better Than Fish Oil

Until recently, fish oil has been the omega-3 supplement of choice.

But now there’s an alternative that may be superior — krill oil.

Krill are small shrimp found in the waters of the Antarctic.

Krill oil is more bioavailable and more readily absorbed than fish oil. (73)

The DHA molecules in krill oil are attached to phospholipids, which facilitate their passage through the intestinal wall and increase their uptake by the brain. (74)

Since krill oil is absorbed more efficiently, you can achieve similar benefits with lower doses. (75)

This also means it’s easier to digest and is less likely to leave a fishy aftertaste.

Krill oil is also an excellent source of astaxanthin, an extremely potent antioxidant that naturally keeps krill oil fresh. (76)

Astaxanthin is a carotenoid that gives shrimp its pink color and makes krill capsules red.

Astaxanthin readily crosses the blood-brain barrier, allowing it to easily neutralize free radicals and halt oxidative damage to brain cells. (77)

Note that krill oil should be avoided if you’re allergic to shellfish.

Algal Oil Shows Potential

Algal oil is extracted from algae and may provide a viable vegetarian alternative to fish and krill oils.

Omega-3 supplements from algal oil contain mostly DHA, along with smaller amounts of EPA and ALA. (78)

One benefit of algal oil is that it may contain fewer contaminants like mercury. (One study found that taking algal oil for 14 days produced similar blood levels of DHA and EPA as eating cooked salmon. (80)

Another study found that women who took algal oil also had an increase in DHA and EPA levels.

And while it seems likely that algal DHA will deliver the same health benefits as DHA from fish oil, more studies are needed before this is known for sure. (81)

Flaxseed Oil — Skip This!

Flaxseed oil has a low conversion rate of ALA to the more healthy and effective EPA and DHA.

Studies show that flaxseed oil does not increase blood levels of DHA, the most important omega-3 for your brain. (8283)

So flaxseed oil really is not really a contender.

Omega-3 Dosages, Side Effects, and Interactions

There is no Recommended Dietary Allowance (RDA) for omega-3 fatty acids in general or for the individual omega-3s, i.e., EPA or DHA.

Most research studies have found that participants benefited from 500 to 1,000 milligrams of total omega-3s per day, so this is a basic dosage rule of thumb.

Experts generally recommend 500 to 1,000 mg of total omega-3s per day to maintain health and avoid deficiency, but therapeutic doses (to raise low levels or treat a health condition) up to 3 grams are generally considered safe. (84, 85)

However, some studies use much more than this.

Renowned neurology researcher Dr. Datis Kharrazian, author of Why Isn’t My Brain Working?, recommends 5 grams of fish oil daily for patients with issues like depression, bipolar disorder, or memory loss, with the emphasis on DHA rather than EPA.

Note that when considering dosages, you should consider the total amounts of EPA and DHA, not the total amount of fish oil or krill oil. (86)

You can see if you are getting adequate omega-3s with this omega-3 quiz created by, a not-for-profit educational organization.

Omega-3 Supplement Side Effects and Interactions

Omega-3 supplements are considered generally safe, with a few exceptions. (87)

If you regularly take aspirin or a blood-thinning drug like warfarin, talk to your doctor before taking any omega-3 supplement.

Fish oil is known to increase the chance of bruising or bleeding.

Fish oil can decrease blood pressure so taking it with high blood pressure medications may cause blood pressure to drop too low.

In some rare instances, fish oil can worsen the symptoms of depression or bipolar disorder.

And lastly, don’t take fish oil or krill oil if you are allergic to seafood.

Omega-3 Benefits for the Brain: The Bottom Line

Omega-3 essential fatty acids are some of the most important nutrients for your brain health, mental well-being, and overall health.

But deficiency is rampant due to poor dietary choices and the degradation of our food supply.

Here’s a quick summary of what you need to know to get the omega-3s you need:

  • Do not rely on plant sources for omega-3 benefits. Plants are not reliable sources of EPA and DHA, the most effective omega-3 essential fatty acids.
  • To get maximum omega-3 benefits from animal sources, look for products labeled wild-caught, grass-fed, pasture-raised, or free range.
  • The omega-3 benefits of moderate fish consumption can outweigh the risks, especially if you are eating wild-caught, cold water fish.
  • Most people benefit from a high-quality omega-3 supplement. The most popular form is fish oil, but there’s evidence that krill oil may be a better choice.