In this Ultimate Supplement Guide, we summarize the scientific literature and answer all of the questions about omega-3 that people are asking the most. Find out what are omega-3 fatty acids, what are their health benefits and how much omega-3 you actually need.
There are very few nutrients that medical scientists have studied more than omega-3 essential fatty acids. Even generations before most of the studies, people supplemented with cod liver oil for the numerous health benefits omega-3 provides.
This article contains more than 50 citations from reputable medical websites and scientific studies. We dug through mountains of medical literature so you don’t have to.
If you have any questions, concerns, or even rebuttals, please contact us or leave a comment below. Don’t be a stranger.
The term omega-3 refers to a group of fatty acids. Three forms of it are considered essential fatty acids. The word “essential” means your body needs them. They are important parts of the membrane of each of your body’s cells. Your body doesn’t make omega-3. You have to get it from foods and/or supplements. (1)
Omega-3 comes in 11 forms. The three normally regarded as the most important forms are considered essential fatty acids. They are called alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA – which is found in plant foods like flax, nuts, and soy – is far less bioavailable than the other two. This means your body will absorb and use a smaller percentage of it by weight. (1)
This does not mean vegetarians or vegans will not get enough omega-3 from plant sources that provide only ALA. They just need more ALA than they would EPA or DHA, both of which come primarily from fish and seafood. The body will turn some ALA into EPA and a smaller amount of it into DHA.
The percentage of ALA your body will absorb may vary a lot, depending on factors such as:
- Being a young woman of reproductive age (2)
- Being pregnant
- Being a young and healthy man (3)
- Whether you consume large amounts of omega-6 fatty acids (4)
The unused ALA will be stored and/or used for energy like other fats. (5)
To elaborate, high omega-6 intake decreases your ability to convert ALA to the more usable omega-3 forms. So does being a young male instead of a young female. Young men may need to consume twice as much ALA as young women for the same effects.
Keep reading, and you’ll learn what omega-3 fatty acids do for you, the benefits they provide, proper dosages, side effects, and more.
DPA: The “Newest” Omega-3 Fatty Acid
There is a fourth omega-3 compound that scientists have recently begun studying more frequently, and that is docosapentaenoic acid (DPA). Babies typically get equal portions of DPA and DHA – and a smaller portion of EPA – from human breast milk. From fish oils and seafood – the primary sources of DHA and EPA – you will get DPA, too, but far less of it than the others. However, your body absorbs and uses DPA more efficiently than others. (6)
DPA can convert to EPA and DHA in the body.
Like the other omega-3 types, DPA is a polyunsaturated fatty acid (PUFA). It is sometimes considered an “intermediary” essential fatty acid and sometimes just a PUFA. Scientists still argue about whether it should be considered a type of omega-3 at all.
The more DPA is studied in medical science, the more important it is reported to be. New studies tend to reveal new benefits.
How do Omega-3 Essential Fatty Acids Work?
While there is a lot of overlap between DHA, EPA, DPA, and ALA, they all have different functions as well.
- Your skin, brain, and eye cells have a lot of DHA. (7)
- EPA may play a bigger role in fighting inflammation than the others because your body uses it to produce anti-inflammatory molecules called eicosanoids. It is also widely recognized for its role in cardiovascular health. (8)
- DPA is increasingly being recognized for its anti-inflammatory, cognitive, and cardiovascular benefits, but the knowledge base is young.
Omega-3 is involved in so many body processes that you won’t begin to get a clear picture of their numerous jobs until you get to the What are the Benefits section below.
Your brain is 60% fat. A significant percentage of this fat is omega-3 in the form of DHA.
According to animal studies, deficiency in omega-3’s DHA form in developing brains can cause: (9)
- Problems generating new brain cells
- Learning disabilities
- Vision problems
- Neurotransmitter metabolism issues.
Your brain cells contain DPA and EPA. However, the amount of DHA is hundreds of times greater. All of them play a role in brain health. DHA helps keep your brain cell membranes more fluid and elastic and ensures they can signal to other brain cells properly. (10)(11)
List of Plant-Based ALA-Rich Foods
The top plant sources of ALA are: (12)(13)
- Flaxseed oil
- Chia seeds
These are the clear winners among plant sources of ALA omega-3.
One U.S. tablespoon, or 14.8mL, of flaxseed oil, can give you 6,700mg to 7,300mg.
An ounce (28.35g) of dried chia seeds provides 5,100mg.
An ounce of walnuts can give you 2,600mg.
Honorable mentions go to hemp seeds, hemp hearts, walnut oil, canola oil, and soybean oil. Be mindful that canola and soybean oils are also high in omega-6 fatty acids. They decrease your body’s absorption of omega-3 because these two groups compete with each other. Safflower and sunflower oils are also high in omega-6.
Plant-Based DHA-Rich & EPA-Rich Foods
If you do a quick internet search on plants that deliver the DHA and EPA forms of omega-3, you may find websites that tout seaweed as a good source. If you look a little closer, you’ll find that 10g of nori seaweed will yield only 10mg-20mg of omega-3. Wakame seaweed will yield the same amount. You will need to eat hundreds of grams of seaweed to meet daily omega-3 standards. On the bright side, seaweed has far more omega-3 than omega-6. (14)
If you’re a vegetarian looking for direct sources of DHA and/or EPA, your best bet is to go with algae-based (algal) oil. Most algal oil supplements provide DHA and very little EPA. However, some do deliver a lot of both. The human body absorbs the DHA in algal oil fairly easily. (15)
List of Non-Plant DHA-Rich & EPA-Rich Foods
The foods highest in DHA and EPA are seafood like fatty fish and shellfish.
The top non-plant food sources of DHA and EPA are: (16)
- Cod liver oil
100g (3.5oz) of salmon gives you 2,260mg of total omega-3. Herring and anchovy supply a similar amount. Compare that to 1,480mg from sardines. 100g of oysters will yield 435mg of omega-3, roughly a full day’s worth for the average person. Cod liver oil provides almost 2,700mg per tablespoon (14.8mL).
Omega-3 Relieves Depression Symptoms
In a Norwegian study of nearly 22,000 participants in their 40’s and 70’s found that 2.5% of those who used cod liver oil daily had “High levels of depressive symptoms.” 3.8% of non-users had these symptoms, so they experienced the symptoms at 1.5 times the rate of users. Those who used cod liver oil for longer periods had symptoms at lower rates than those who used it for shorter periods. (17)
In a 2016 analysis of existing randomized placebo studies of people with major depressive disorder, scientists concluded that high-dose (1,000mg-6,000mg) omega-3 supplementation improved symptoms significantly. Omega-3 supplements with antidepressants were even more successful. Omega-3’s EPA form and combinations of EPA and DHA proved more successful than DHA alone. (18)
Another analysis of studies singled out EPA as a mood-improver and anti-inflammatory agent in cases of major depressive disorder. They noted that successful supplements were limited to those with EPA levels of at least 60% of total omega-3. Any supplement with a ratio lower than 60/40 EPA/DHA was ineffective at improving depression symptoms. (19)
This is why Ultra Pure Omega-3 by Intelligent Labs is 60/40 EPA/DHA.
Omega-3 Lowers Anxiety
Healthy medical students tested 20% lower for anxiety symptoms than those who took a placebo in a 12-week 2011 study. The omega-3 supplement they took daily was over 2,000mg EPA and 348mg DHA. The best results occurred in those with higher omega-3 to omega-6 ratios in blood samples. (20)
A 2018 analysis of studies demonstrated that omega-3 successfully reduced anxiety in those with and without anxiety-related diagnoses. Researchers noted that the placebo studies bringing significant results used omega-3 doses of 2,000mg or more per day. Those with specific anxiety-related diagnoses received the greatest benefits. There was a total of 1,203 participants in the studies they looked at. (21)
Omega-3 Reduces Severity of ADHD Symptoms
In a 2017 review of 16 controlled studies of children and young people with Attention Deficit Hyperactivity Disorder (ADHD), researchers reported improvements in impulsive behaviour, hyperactivity, attention span, reading, visual learning, working memory, and short-term memory. They said supplementation with omega-3 and omega-6, depending on dosages, can help reduce the above ADHD symptoms alone and alongside traditional drug-based treatments. (22)
Omega-3 Lowers Inflammation
Omega-3’s EPA form has gained attention for its ability to fight chronic inflammation.
A 2017 animal study demonstrated that some of your omega-3 converts to anti-inflammatory cannabinoids in the body. (23)
Scientists are creating ongoing studies to determine omega-3’s ability to help prevent or alleviate a variety of inflammation-related diseases.
Researchers at the Norwegian University of Science and Technology (NTNU) suggested that omega-3 may help patients with Alzheimer’s Disease, multiple sclerosis, meningitis, and even some forms of cancer while calling for more studies. They examined its anti-inflammatory processes and how they work. The research includes reviews of existing studies. (24)
Studies of EPA’s effects on depression symptoms point to anti-inflammatory mechanisms that are responsible for the results. They also suggest that these same mechanisms slow the ageing process.
Protects the Brain & Slows Cognitive Decline
Studies of multiple forms of omega-3 confirmed that high blood levels of Omega-3 help protect the brain from cognitive decline. Omega-3 strengthens the integrity of neural circuits and leads to healthy cognitive ability in healthy older adults. One study found that even Omega-3’s ALA form from plant sources can improve brain health in old age. (25)
People with Alzheimer’s Disease tend to have low levels of omega-3 in the brain. However, a 2016 review of studies did not find much benefit from omega-3 for people who already have Alzheimer’s. The researchers did suggest that some people may experience improvements in some daily living tasks after supplementing for a year or more. They recommended more studies to test the effects of different dosages and durations. (26)
Scientists probably haven’t studied all the different dosage levels of EPA/DHA combinations that could help people with Alzheimer’s. None of them says that no more research is needed to settle the issue.
Omega-3 Promotes Learning, Memory & Cerebral Blood Flow
A 2017 study noted higher cerebral blood flow in particular brain regions, along with improved memory and learning ability, in humans with higher levels of omega-3. Scientists looked at EPA and DHA omega-3 forms specifically. (27)
A smaller 2018 study of those with mild cognitive impairment noted improved blood flow and blood volume in cerebral areas normally associated with cognitive impairment. They looked at five omega-3 users and eight people who took a placebo. (28)
People 50-75 years old who took 2,200mg daily for 26 weeks scored significantly better in object-location memory tests than a placebo group in a 2017 study of 44 people. (29)
A study of 11 healthy women and men, 18-25 years old, measured omega-3’s ability to improve working memory. Those who took fish oil capsules for six months improved working memory by an average of 23%. (30)
A 2015 study looked at 485 people with an average age of 70 and normal levels of age-related memory complaints. The omega-3 group took 900mg of omega-3’s DHA form from an algae-based supplement daily for 24 weeks. Everyone took a memory test that required them to recall where certain patterns appeared on a computer screen. At first, both the DHA and placebo groups averaged 13 out of 30 possible mistakes. After 24 weeks, the DHA people averaged 8.5 (13 – 4.5). The placebo people averaged 10.6 (13 – 2.4) mistakes. Both groups improved, but the omega-3 group improved more. (31)(32)
Omega-3 Slows Skin Aging
Omega-3’s EPA and DHA forms are considered essential skin nutrients. Multiple studies show that both oral and topical use helps keep skin healthy and wrinkle-free. They provide anti-inflammatory benefits and act as antioxidants. They also improve moisture levels, elasticity, firmness, and other measures of skin health. One study gave credit to 2,200mg daily oral doses of ALA from flaxseed oil for improved skin health as well. (33)
Helps Prevent Hair Loss
Omega-3 helps keep the scalp hydrated, increases hair density, and reduces hair brittleness and hair loss.
A 6-month study of 120 healthy women in 2015 examined their hair after supplementing with omega-3, omega-6, and specific antioxidants for six months. The vast majority of them experienced lower hair loss, higher hair density, and improved hair diameter compared to placebos. (34)
Medical scientists in 2018 examined the effects of omega-3’s DHA form on hair growth in mice. They used fermented fish oil extract from mackerel. The extract promoted hair growth similarly to the way minoxidil, the “Hair Club for Men” drug, does. (35)
Soothes Stiff & Painful Joints in Arthritis Patients
Arthritis Today Magazine noted a lot of studies that show omega-3 can reduce inflammation-related symptoms like pain, soreness, and stiffness. (36)
One 2013 study looked at rheumatoid arthritis sufferers who took high doses of fish oil along with the standard “triple therapy” of methotrexate, sulfasalazine, and hydroxychloroquine. The fish oil group achieved remission at double the rate and enjoyed overall better outcomes than the group receiving only the standard treatment.
Other studies demonstrate that omega-3 reduces joint pain but has little or no effect on joint tissue damage. However, it may produce chemicals that help prevent joint damage caused by immune responses.
Boosts Athletic Performance
In 2011, Spanish researchers found that DHA can improve complex reaction time and related abilities in elite female soccer players. Complex reaction time is also known as decision-reaction time, elite soccer players already score well for that skill. They tested 24 players who had to use both hands and both feet to react to simulated events by pushing buttons and pedals. (37)
One group took 3.5g of high-DHA fish oil daily, and the other took olive oil. The fish oil improved performance significantly. (37)
The authors also noted other studies proving DHA’s ability to decrease and delay fatigue and reduce muscle-related oxidative stress in athletes. These benefits are well-known.
Omega-3 Quickens Sports Recovery
Omega-3 can make workouts and sports games feel easier to perform by increasing endurance and reducing the energy needed to get the job done. The anti-inflammatory effects can help prevent a lot of muscle soreness and swelling.
In 2011, researchers looked at inflammation caused by eccentric arm curl exercises. In two trials, they measured arm swelling, temperature, self-reports of soreness, and other indicators of inflammation before exercise and 48 hours later. In trial 1, participants restricted omega-3 intake for 14 days. In trial 2, they took 3,000mg of omega-3 from fish oil daily for seven days. Trial 2 exercises caused 15% less soreness than those in trial 1. Arm circumference increased in trial 1 but not in trial 2. Omega-3 did not affect temperature. (38)
In 2011, another study examined 20 rugby players during pre-season training. The omega-3 fish oil dose contained 551mg each of the DHA and EPA forms, and they took it twice daily for five weeks. The placebo was protein-based. Researchers measured soreness, fatigue, sleep, stress, and mood each morning. They also measured countermovement jump performance (CMJ) once or twice weekly. Omega-3 users did moderately better in tests of muscle soreness, CMJ, and fatigue. (39)
Does Omega-3 Improve Blood Sugar Levels & Insulin Resistance?
Studies of omega-3’s effects on blood sugar and insulin resistance are all over the place. We include this section because there is a lot of confusion in conversations on this topic.
In 2015, researchers performed 20 randomized controlled trials and found more questions than answers. Factors that affect blood sugar may include the ratio of omega-3’s DHA and EPA forms, medical conditions, dosages, duration of use, ethnicity, and hormones created in the body by omega-3 use. (40)
Supports Fetal Development During Pregnancy
According to the American Pregnancy Association, omega-3’s DHA and EPA forms are important during pregnancy: (41)
“Research has confirmed that adding EPA and DHA to the diet of pregnant women has a positive effect on the visual and cognitive development of the baby. Studies have also shown that higher consumption of omega-3 may reduce the risk of allergies in infants.
“Omega-3 fatty acids have positive effects on the pregnancy itself. Increased intake of EPA and DHA has been shown to prevent pre-term labour and delivery, lower the risk of preeclampsia, and may increase birth weight. Omega-3 deficiency also increases the mother’s risk of depression. This may explain why postpartum mood disorders may become worse and begin earlier with subsequent pregnancies.”
A 2003 study published in the journal Pediatrics showed that mothers who supplemented daily with 2,500mg of omega-3 during pregnancy had children who scored higher on IQ tests at four years of age than other kids. (42)
Always talk to your doctor before using supplements or eating fish if you are pregnant. Mercury is abundant in some omega-3 foods and supplements. On the other hand, an omega-3 deficiency could cause more damage to your baby’s cognitive health than mercury poisoning. (43)
Your doctor may help you determine proper dosages and omega-3 sources to optimize health and avoid problems. Nothing in this article should act as a substitute for sound and personalized medical advice.
Lowers Blood Pressure
In 2015, Cleveland HeartLab’s blog touted an analysis of studies of the effects of omega-3 on blood pressure that was published in the American Journal of Hypertension that same year. (44)
In the blog, they noted, “Omega-3 fatty acids EPA and DHA – found in fatty fish and fish oil supplements – reduce blood pressure as effectively as lifestyle changes such as exercising more, cutting back on salt, or limiting alcohol.” (45)
Promotes Muscle Growth
Omega-3 fuels protein synthesis. Washington School of Medicine researchers tested a prescription supplement more concentrated with omega-3 than fish oil on nine healthy adults between the ages of 25 and 45. The supplement increased their muscle-building ability within the 8-week study. (46)
Optimizes Heart Health
Omega-3 can help those with high blood pressure, which increases the risk of heart attacks. Inflammation can damage blood vessels and increase the risk of heart disease. Omega-3 lowers inflammation. It also reduces blood clotting. (47)
Omega-3 also lowers “bad” cholesterol and slows plaque growth in your arteries. (48)
Relieves Dry Eye Symptoms
A 2011 study of 36 patients with dry eye found that a 750mg daily serving of omega-3 (450mg EPA, 300mg DHA) eliminated symptoms in 70% of patients within 90 days. In the placebo group, 37% became symptom-free during the same period. (49)
Different government agencies give different guidelines or no guidelines.
The U.S. Academy of Nutrition and Dietetics recommends 500mg, split between the DHA and EPA forms, each day. This guidance is generic and designed to prevent deficiency, which causes upwards of 100,000 American deaths each year. The American Heart Association recommends 2,000-4,000 total milligrams of omega-3’s DHA and EPA forms, under the care of a physician, for those who wish to lower triglycerides. The 2015–2020 Dietary Guidelines for Americans recommends 250mg per day from seafood to lower the risk of cardiovascular diseases. That’s approximately 1/2lb (227g) of seafood weekly. They also say this can reduce the risk of death in people who already have cardiovascular diseases. (50)
The U.S. Food and Drug Administration requires that supplement labels recommend a daily total of no more than 2,000mg of DHA and EPA. (50)
The truth is, the amount of omega-3 you need daily may vary a lot, depending on medical conditions and other factors. Many of the dosages in the above studies were much higher than 500mg.
For symptom control and disease prevention, you might need high doses, depending on what you want to achieve. Omega-3 is generally safe enough to allow you to aim much higher than 500mg per day, especially if you’re currently healthy. (51)
Talk to your healthcare provider about optimal dosages for preventing or treating particular health conditions. Some goals may require specific ratios of EPA to DHA or omega-3 to omega-6.
How Much Omega-3 vs Omega-6 Do We Need Each Day?
Just like omega-3 dosage, your optimal omega-3 to omega-6 ratio may depend on a lot of factors. Generally, the higher the omega-3 to omega-6 ratio, the better. Standard western diets these days are much higher in omega-6 compared to omega-3, and it should be the other way around.
A standard generic recommendation is a 4 to 1 or lower ratio of omega-6 to omega-3. (52)
This doesn’t mean omega-6 is bad. Some of the recommended treatments in the above studies include omega-6 because these compounds enhance the effectiveness of omega-3 for some conditions.
Like omega-3, omega-6 is a group of polyunsaturated fatty acids (PUFA’s) that are considered essential fatty acids. They produce chemicals that help your immune system, but eating too much of them can increase inflammation and harm your health. (53)
Omega-6 also competes with omega-3 and reduces the amount of omega-3 your body absorbs and uses.
To summarize: Talk to your healthcare provider if you want to optimize the omega-3 to omega-6 ratio to fight or prevent a particular health condition. Otherwise, consume no more than four times as much omega-6 than omega-3 to optimize your overall health.