It’s critical to supplement with DHA, a key omega-3 fat, to build and preserve brain health and function for everyone from babies to adults.
The human brain is largely made of fat, 60% by dry weight.
One particular group of fats, the omega-3 essential fatty acids, is the most important for the brain’s structural integrity and performance.
And one omega-3 fatty acid, DHA, may be the single most critical nutrient for brain health throughout life.
DHA: An Essential Building Block of the Brain
Essential fatty acids are the fats we need for health that our body can’t synthesize; we have to get them from food or supplements.
Of all the essential fatty acids, the omega-3s are the most abundant in the brain.
They are the preferred building blocks of brain cell membranes and nerve cells.
When omega-3s aren’t available, the brain will use whatever fats are available, but this leads to suboptimal brain cells.
There are three main kinds of omega-3s — DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid), and ALA (alpha-linolenic acid) — with DHA unarguably being the most important for the brain.
“ According to the US National Institutes of Health, the average North American consumes only 20% of the recommended amounts of DHA and EPA.
DHA accounts for 97% of the omega-3 fatty acids in the brain.
It’s a major structural component of the cerebral cortex, the part of the brain responsible for memory, language, creativity, emotion, and attention.
DHA plays an important role in brain cell communication.
It supports optimal levels of the most important neurotransmitters, including dopamine, serotonin, GABA, norepinephrine, and acetylcholine.
DHA also improves the function of neurotransmitter receptors, allowing the brain to better utilize these brain chemicals.
Interestingly, fossil evidence suggests that the evolution of our large human brains depended on the availability of DHA from seafood.
Benefits of DHA Supplements During All Stages of Life
DHA has proven helpful for a wide range of diseases, including arthritis, atherosclerosis, depression, diabetes, heart disease, and some cancers.
Just as the body needs calcium for strong bones, it needs DHA for a strong central nervous system.
Here’s a look at how DHA is needed throughout all stages of life for a healthy brain and mental well-being.
DHA for Babies’ Brain Development
Optimal levels of DHA are critical for the development of babies’ brains.
New mothers are advised to take supplemental DHA to ensure that there will be adequate amounts available for their baby’s rapidly growing brain; many prenatal vitamins include DHA.
DHA is a natural component of breast milk and is often added to baby formulas to boost its nutritional profile.
It’s not easy to run cognitive tests on babies (!), but formula-fed infants given a DHA supplement perform better on face recognition tests than those babies fed formula without it.
DHA Supplement Benefits for Children
DHA isn’t just for newborns, it’s important during childhood too.
Attention deficit hyperactivity disorder (ADHD) is the most common neurological condition in children.
Numerous studies show that when children with ADHD are given supplemental omega-3s (both DHA and EPA), they experience significant improvement in attention, hyperactivity, defiant behavior, and sleep.
One study found that children with major depressive disorder experienced a 40% decrease in depressive symptoms when given DHA supplements.
DHA Supplements for Better Adult Mental Health
There’s abundant evidence that taking a DHA supplement can make you a happier, smarter adult.
DHA Preserves Brain Volume
The human brain naturally shrinks with age, but DHA helps to preserve brain volume.
People low in DHA have smaller brains that age faster than those with normal levels.
Unfortunately, this is a large group since 80% of the world’s population has a subpar intake of omega-3s.
DHA Increases BDNF
DHA increases brain-derived neurotrophic factor (BDNF).
BDNF is a protein that keeps existing brain cells healthy and stimulates new brain cell formation.
DHA Increases Brain Plasticity
DHA also increases brain plasticity.
Neuroplasticity is the brain’s capacity to form new brain cells and neural connections and improve its capabilities throughout life.
In one clinical trial, healthy adults were given 800 mg of DHA plus 1600 mg of EPA.
Study participants experienced an increase in vigor and a decrease in anger, anxiety, fatigue, depression, and mental confusion after only 35 days of supplementation.
DHA Deficiency Impairs Cognitive and Mental Health
DHA deficiency impairs many cognitive functions such as memory, problem solving, the ability to multitask, and thinking capabilities.
Low DHA levels have been linked to depression, ADHD, anger, and hostility.
Serious psychiatric disorders such as major depressive disorder, suicidal behavior, bipolar disorder, and schizophrenia have also been linked to DHA deficiency.
Military veterans are at increased risk for depression, anxiety, and suicide and those with low levels of DHA are 62% more likely to commit suicide.
Surprisingly, low DHA is a stronger predictor of suicide than combat-related stress.
But omega-3 and DHA supplementation were found to improve anxiety and depression scores and reduce suicidal thinking by 45%.
Additionally, DHA can help prevent postpartum depression which affects 1 in 9 women after they give birth.
DHA Supplements Protect Seniors Against Mental Decline
If you take only one nutritional supplement to help stay mentally sharp as you age, it should be DHA.
Adequate levels of DHA can improve memory and learning and protect against age-related mental decline in healthy older adults.
Numerous studies show that seniors with higher levels of omega-3s, specifically DHA, have significantly less risk of developing dementia or Alzheimer’s.
One landmark study that followed a group of seniors for nine years found that those with higher levels of DHA were 47% less likely to develop dementia and 39% less likely to develop Alzheimer’s than those with low levels.
High intake of DHA is also associated with reduced risk of neuroinflammation, macular degeneration, stroke, and Parkinson’s disease.
Why DHA Supplementation Is Necessary
The evidence is clear: DHA is critical for brain health and function.
But do you really need to supplement?
Or is it possible to get enough DHA from food alone?
According to the US National Institutes of Health, the average North American consumes only 20% of the recommended amounts of DHA and EPA.
This is because few people regularly consume the main dietary sources of DHA and EPA — cold-water fatty fish such as salmon, herring, mackerel, halibut, sardines, and bluefin tuna.
This chart shows the DHA and EPA content of the most commonly eaten seafood items in the United States.
You can see that salmon stands alone with roughly 4-14 times more DHA per serving than the other seafood items on this list.
Unfortunately for vegetarians, there are no good plant food sources of DHA.
Only small amounts of omega-3s are found in nuts, flax, seeds, and sea vegetables, and always in the form of ALA rather than DHA.
Research shows that even large amounts of dietary ALA have little effect on blood levels of DHA.
This is because the process that converts ALA into DHA is extremely inefficient.
In fact, less than 0.5% of ALA found in plants gets converted into the DHA the brain needs.
The bottom line is that unless you eat fatty fish several times a week, it’s impossible to get adequate DHA through diet alone.
But you can remedy this by taking a DHA supplement or an omega-3 supplement.
DHA Supplement Sources Compared
DHA is most commonly found in fish oil supplements.
You can get DHA from supplements in two ways:
- You can buy a single-ingredient DHA supplement. These are almost always extracted from fish oil.
- You can buy a supplement that contains DHA as one of the main ingredients.
Here’s a look at various other sources of DHA.
Each has its own set of benefits and drawbacks.
Why Krill Oil Is an Excellent Source of DHA
Krill oil is an alternative to fish oil that is growing in popularity.
Krill are small shrimp-like crustaceans found in all the world’s oceans.
If you check the label of a krill oil supplement, you’ll notice that it contains less DHA than comparable fish oil supplements.
However, krill oil is more bioavailable and more readily absorbed than fish oil, and consequently often outperforms fish oil in clinical trials.
The DHA molecules in krill oil are attached to phospholipids, which facilitate the passage of DHA through the intestinal wall and increase uptake into the brain.
Since krill oil is absorbed more efficiently, you can achieve benefits similar to fish oil from lower doses.
However, krill oil supplements usually cost more per dose than fish oil.
The Benefits of Algal DHA Supplements
Some DHA supplements are made from algae.
Algal DHA supplements are a good option for people who don’t eat seafood due to food allergies or dietary preference.
But are they as good as DHA sourced from fish oil?
Fish get their DHA from eating smaller fish which, eventually down the food chain, get their DHA from algae.
By getting your DHA from algae directly, you are simply cutting out the middleman (middlefish?).
One potential benefit of algal DHA is that it may contain fewer contaminants like mercury.
And while it seems likely that algal DHA will deliver the same health benefits as DHA from fish oil, this is not known for sure and experts agree that more studies are needed.
Why Flaxseed Oil Is Not a Good Source of DHA
Like all vegetable sources of omega-3s, flaxseed oil contains ALA which is poorly converted to DHA.
Furthermore, research finds that flaxseed oil does not increase blood levels of DHA.
So flaxseed oil should not be considered as a viable source of DHA.
Beware of Foods Fortified With DHA
Hundreds of food items from energy bars to orange juice are now fortified with DHA.
But be forewarned that unless the label specifically states the source, these foods almost certainly contain mostly ALA from inferior sources such as flaxseed, canola oil, or soybean oil, which will not raise your blood levels of DHA.
The Benefits of DHA Compared to EPA
If you read the labels of fish or krill oil supplements, you’ll see that, in addition to DHA, they contain EPA.
EPA is often recommended for heart health, but it has brain benefits too.
While both DHA and EPA are anti-inflammatory, EPA is superior to DHA at calming inflammation, including brain inflammation.
Chronic inflammation of the brain can lead to anxiety, depression, bipolar disorder, schizophrenia, and memory loss.
And EPA is specifically helpful for treating borderline personality disorder.
You need both EPA and DHA, but many experts believe you should look for a supplement that contains a high proportion of DHA or take extra DHA separately for optimal brain function.
For example, award-winning Harvard researcher Datis Kharrazian, PhD, DHSc, author of Why Isn’t My Brain Working?, recommends supplementing with a DHA to EPA ratio as high as 20:1 for issues like depression, bipolar disorder, or memory loss.
DHA Supplement Dosages
There is no Recommended Dietary Allowance (RDA) for DHA and recommended dosages vary widely depending on where you look and who you listen to.
However, experts generally recommend 500-1000 mg of total omega-3s per day to maintain health and avoid deficiency.
But therapeutic doses up to 3 grams daily are generally considered safe.
A US National Institutes of Health workshop that included omega-3 experts from around the world determined that a minimum adequate intake (AI) of 220 mg each of DHA and EPA is required for optimal health in adults.
If you want to learn more about recommended DHA or EPA dosages, the Global Organization for EPA and DHA has published a comprehensive guide, Global Recommendations for EPA and DHA Intake.
If you are pregnant, talk to your doctor about a DHA supplement and stick with products designed for pregnant women.
How to Read an Omega-3 Supplement Label
It’s not always clear which numbers are important when looking at an omega-3 supplement label.
Here’s a typical label:
First, note that there is 2200 mg of total fish oil and 2000 mg of total omega-3 fatty acids per serving size.
Of that, 1400 mg is EPA while only 480 is DHA.
This means that only 22% of this supplement is DHA.
This percentage of DHA is fairly standard.
DHA Side Effects and Interactions
DHA supplements are generally safe but can cause digestive upset.
Taking them with meals can help.
DHA can increase blood sugar levels in type 2 diabetics and can decrease the effectiveness of diabetes medications.
DHA can decrease blood pressure, so taking DHA along with medications for high blood pressure can cause blood pressure to drop too low.
One common warning for fish oil supplements is that they are not to be taken with blood-thinning medications like warfarin or aspirin.
It seems that EPA is largely responsible for the blood-thinning effects of fish oil and that taking DHA alone does not have the same effect.
And, of course, don’t take fish oil or krill oil if you are allergic to seafood.
DHA for Children
If you are planning to take DHA during pregnancy or give it to your kids, I recommend the DHA/EPA Omega-3 Institute as a source of information.
They have an excellent “frequently asked questions” page that covers many aspects of DHA supplementation, including dosages for children.
Talk to your doctor if you are pregnant or nursing, or talk to your pediatrician before giving your child a DHA supplement.
Recommended: Upgrading brain health is key to making your brain work better.
Brain supplement can help you:
- Improve your mental clarity and focus.
- Boost your memory and your ability to learn.
- Increase your capacity to think critically, solve problems, and make decisions.
P.S. Like what you’ve read on this page? Get more like this — Sign up for our emails.
