by Deane Alban
ON AUGUST 25, 2015
The human brain is largely made of fat — 60 percent by dry weight. One particular group of fats, the omega-3 essential fatty acids is most important for the brain’s structural integrity and performance (1). And one omega-3 fatty acid, docosahexaenoic acid (DHA), may be the single most important nutrient you can take for brain health throughout all stages of life. DHA doesn’t sound as exciting as the latest brain supplement but it’s a foundational nutrient needed for a healthy, optimally functioning brain. Trying to build a healthy brain without it is like building a house on a foundation of Legos!
DHA: An Essential Building Block Of The Brain
Essential fatty acids are those your body needs for health that can’t be synthesized by your body — you have to get them from food or supplements. Of all the essential fatty acids, the omega-3s are the most abundant in the brain where they are the preferred building blocks of brain cell membranes and nerve cells (2). There are three kinds of omega-3s — EPA, ALA, and DHA — with DHA unarguably being the most important for your brain. DHA accounts for 97 percent of the omega-3 fatty acids in the brain (3). It’s a major structural component of the cerebral cortex, the part of the brain responsible for memory, language, creativity, emotion and attention (4).
When omega-3s aren’t available, your brain will use whatever other fats are available, leading to suboptimal brain cells. Being low in DHA actually results in a structurally smaller brain (5). Besides being a major structural component, DHA also plays a role in brain cell communication. DHA facilitates neurotransmitter activity and increases the number of neurotransmitter receptors, allowing the brain to optimize the use of its “feel good” brain chemicals like serotonin and dopamine (6).
Benefits Of DHA In All Stages Of Life
Just as you need calcium for strong bones, you need DHA for a strong nervous system. 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 (7). There’s little doubt that pregnant women need more omega-3s and DHA than usual (8). DHA is a natural component in breast milk. New mothers can take a DHA supplement to ensure there will be adequate DHA for their baby’s rapidly growing brain (9). DHA is often added to baby formulas to fill in this nutritional gap (10). Formula-fed infants given a DHA supplement do better on cognitive tests like face recognition than those fed a standard formula (11). Extra DHA is not only good for babies, it’s good for their moms too since it can prevent postpartum depression (12).
DHA For Children: 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 (13, 14). One study found that children with major depressive disorder experienced a 40 percent decrease in depressive symptoms when given DHA supplements (15).
DHA For Seniors And Mental Decline: If you could take only one supplement to stay mentally sharp as you age, it would be DHA. People low in DHA have smaller brains that age faster than those with normal levels (16). DHA can improve memory, learning, and age-related mental decline in healthy older adults. Having adequate levels of DHA can protect you from age-related mental decline and significantly reduce your risk of dementia and Alzheimer’s. Seniors with higher levels of DHA are 47 percent less likely to develop dementia and 39 percent less likely to develop Alzheimer’s as people with low levels (17).
DHA For Mental Health
Having low levels of DHA means having a smaller brain and this shrinkage affects brain function. DHA deficiency impairs functions like memory, problem solving, the ability to multitask, and thinking capabilities (18). Low DHA levels have been linked to depression, ADHD, anger, and hostility (19). Serious psychiatric disorders such as major depressive disorder, suicidal behavior, bipolar disorder, and schizophrenia have been linked to DHA deficiency (20, 21, 22, 23). Military veterans with low levels of DHA are 62 percent more likely to commit suicide (24). Surprisingly, low DHA is a stronger predictor of suicide than battle-related stress.
Why Take A DHA Supplement?
You can see that DHA is one of the most important nutrients for your brain. But do you really need to supplement? Why can’t you get enough from food? The main food sources of DHA are seafood, with the best sources being cold water, oily fish such assalmon, herring, mackerel, halibut, sardines, and bluefin tuna (25). This chart compares the DHA and EPA content of the most commonly consumed seafood in the United States.
You can see how favorably salmon compares to other kinds of seafood, having roughly 4 to 15 times more DHA as the other items on this list. Small amounts of omega-3s are found in plant foods such as nuts, flax, seeds, and sea vegetables, but their omega-3 is in the form of alpha-linolenic acid (ALA), not DHA. ALA gets converted into DHA but this conversion process is quite inefficient (26). In fact, less than than 0.5 percent of ALA found in plants gets converted to the DHA your brain needs (27). Unless you eat fatty fish every day, it’s almost impossible to get enough DHA through diet alone. But you can remedy this by taking a DHA supplement or getting your DHA from a fish oil supplement. Fish oil supplements will contain both DHA and the other main omega-3 — EPA (eicosapentaenoic acid).
How Does DHA Compare To EPA?
You’ll find EPA together with DHA in supplements containing fish oil or krill oil (krill are small crustaceans). EPA is often recommended for heart health but brings its own set of brain benefits to the table (28). EPA is superior to DHA at calming inflammation, including brain inflammation. Chronic inflammation of the brain can lead to brain fog, ADHD, anxiety, depression, and memory loss (29, 30). And EPA is specifically helpful for treating borderline personality disorder (31).
But if you are looking for overall brain enhancement, look for a fish oil supplement that contains a high proportion of DHA or take DHA on its own. Many experts believe in hedging your bets and taking a supplement that contains both. The one important exception is when giving supplements to infants or small children. They should be given DHA alone and not one that contains EPA (32). If you are planning to take DHA during pregnancy or to give it to a small child, I recommend the DHA/EPA Omega-3 Institute as a source for information. They have an excellent “frequently asked questions” area. And, of course, talk to your doctor if you are pregnant or nursing, or talk to your pediatrician before giving a child a DHA or fish oil supplement.
What About Algal DHA?
Some DHA supplements are made from algae. Algal supplements contain only DHA and no EPA making them a safe choice for infants and small children (33). Algal DHA supplements provide a good option for people who do not 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 who, eventually down the food chain, get their DHA from algae. By getting your DHA from algae you are simply cutting out the middleman. One benefit of algal DHA is that it may contain fewer contaminants like mercury (34). However, 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 (35).
There is no Recommended Dietary Allowance (RDA) for DHA and recommended dosages vary widely depending on where you look. If you are taking fish oil, a good rule of thumb is a supplement that contains 700 to 1,000 mg of EPA and 200 to 500 mg of DHA daily (36). If you are taking DHA alone, you can take more — up to 1,000 mg per day (37).
Dr. Datis Kharrazian, author of Why Isn’t My Brain Working?, recommends 5 grams of fish oil daily. And for patients with issues like depression, bipolar disorder, or memory loss, he recommends a supplement with a DHA to EPA ratio as high as 20 to 1. If you are using fish oil, DHA or EPA therapeutically, check out WebMD’s omega-3 dosage information. Here you’ll find specific recommended dosages for a wide variety of health conditions based on the latest scientific research. You can find out if you are getting adequate omega-3s with this omega-3 quiz created by a not-for-profit organization.
The Benefits Of DHA Supplements: The Bottom Line
Docosahexaenoic acid (DHA) is one of the omega-3 essential fatty acids and may be the single most important nutrient for overall brain health and function. It’s a major building block of brain cells and enhances brain cell communication. It’s essential for prenatal brain development, good mental health through all stages of life, and for warding off age-related mental decline. It’s found mainly in seafood, particularly cold water, oily fish like salmon and sardines — foods that few of us eat daily. Virtually every brain can benefit from supplementation either in the form of fish or krill oil or an isolated DHA supplement.