Omega-3 Fatty Acids: Foods, Benefits, Facts
Omega-3 fatty acids are essential nutrients, meaning they can’t be produced by the body and need to come from the diet. Despite the importance of omega-3s, most people don’t consume enough of them. Omega-3s provide multiple benefits like protecting eye and brain health.
This article covers the types of omega-3s, benefits, sources, and recommendations.
Verywell / Jessica Olah
What Is Omega-3?
Omega-3 fatty acids are a type of fat that needs to be consumed in foods. The three important types of omega-3s are:
Docosahexaenoic acid (DHA)
Eicosapentaenoic acid (EPA)
Alpha-linolenic acid (ALA)
DHA and EPA are primarily found in algae and fatty fish, such as salmon, sardines, and tuna, while ALA is mostly found in plant foods.
How Much Omega-3 Should You Get Daily?
According to the National Institutes of Health, the recommended adequate intake of omega-3s by age is:
Birth to 1 year: 500 milligrams (mg) daily
1–3 years: 700 mg daily
4–8 years: 900 mg daily
9–13 years: 1,200 mg for males and 1,000 mg for females daily
14–18 years: 1,600 mg for males and 1,100 mg for females daily
18 and older: 1,600 mg for males and 1,100 mg for females daily
During pregnancy: 1,400 mg daily
During lactation (breastfeeding): 1,300 mg daily
The potential benefits of omega-3s include the following:
Protect Eye Health
The DHA type of omega-3 is the primary fatty acid that makes up the eye's retina (layer of tissue in the back of the eye that senses light and signals the brain so you can see). DHA is essential during pregnancy and while breastfeeding to support healthy eye development in the fetus and infant.
It continues to be important throughout your life for eye health. Research suggests adequate omega-3s help reduce the risk of eye problems like age-related macular degeneration (loss of central vision).
Research suggests omega-3s play an important role in preventing inflammation. When the body breaks down omega-3s, it uses them to create anti-inflammatory compounds and antioxidants. So, it helps reduce inflammation and protects cells from damage.
It’s believed that inflammation plays a role in the development of many chronic conditions like heart disease, diabetes, cancer, and arthritis. So reducing inflammation may help lower your risk for these chronic diseases and their symptoms.
Improve Heart Health
Cardiovascular diseases are one of the leading causes of death. Omega 3s may help improve important indicators of heart health and lower the risk of cardiovascular disease. However, the effect may be minor and the evidence is weak.
Raise “good” HDL cholesterol
Reduce blood pressure
May prevent plaques (deposits of fat, cholesterol, and calcium) from forming in arteries
May lower “bad” LDL cholesterol levels
Boost Infant Brain Health
Omega-3s are essential for healthy brain development in the womb and early life. DHA is the main fatty acid used to create the cell membranes in the brain. And most of the brain growth happens during the first six years of life.
Research suggests both EPA and DHA are equally effective at raising DHA levels in the brain. So, consuming adequate amounts of these nutrients is essential during pregnancy and lactation, and in childhood.
Help Autoimmune Diseases
Many autoimmune diseases may be triggered or worsened by chronic inflammation. Reducing inflammation may help to control symptoms and slow disease progression. Inflammation is part of the immune response to infection, disease, and injury.
Autoimmune diseases are conditions in which the immune system mistakes healthy cells for problems and attacks them. Research suggests omega-3s may help reverse the progression of autoimmune and inflammatory diseases like:
Protect Against Alzheimer’s Disease
Changes in brain health and cognitive decline are common side effects of aging. Still, several studies show that omega-3s may protect brain health while aging and lower the risk of Alzheimer’s disease.
One systematic review found that omega-3 supplements may help improve cognitive performance in people with mild Alzheimer’s disease symptoms.
Ease Cancer Treatment Side Effects
Inflammation plays a role in tumor development and the side effects from cancer treatment. Research studies are mixed on whether omega-3s can actually help prevent cancers, such as prostate cancer.
However, a 2013 study showed omega-3 supplementation along with chemotherapy may help improve patient outcomes by reducing inflammation and chemotherapy side effects.
May Reduce Depression
Omega-3s may also protect your brain health by lowering the risk for some mental health conditions, like schizophrenia and depression. A 2019 study found that omega-3 supplements with EPAs helped improve depression symptoms.
14 Foods High in Omega-3s
Usually, it’s best to try and consume essential nutrients through food when possible. In general, animal omega-3 sources provide EPA and DHA, while plant sources tend to have ALA.
Food high in omega-3 fatty acids include:
Fish liver oils, such as cod liver oil and krill oil
How to Take Omega-3
Most of the time, people are able to meet their nutritional needs through a balanced diet. However, sometimes due to food preferences, access to food, or how the body absorbs nutrients, it’s difficult to meet the daily recommendation for nutrients.
If you’re concerned about getting enough omega-3s, talk with your healthcare provider. They may recommend taking a dietary supplement to increase your omega-3s. Your healthcare provider can let you know how much to take and review any potential risks of taking the supplement.
For example, omega-3 supplements may interact with blood thinners, like Coumadin (warfarin), and high doses have been shown to potentially increase the risk of bleeding or stroke (loss of blood supply to the brain or bleeding in the brain).
Potential side effects to taking dietary supplements include digestion discomfort like:
Burping or gas
Diarrhea or constipation
Be sure to research the company before purchasing a dietary supplement. The Food and Drug Administration (FDA) doesn’t regulate supplements as a medication, so the quality, ingredients, and effectiveness aren’t tested.
When to See a Doctor
It’s best to talk with your healthcare provider before starting any dietary supplements. Especially if you are taking it to help manage medical conditions like autoimmune diseases, depression, or heart disease.
Supplements may help manage symptoms, but they aren’t designed to be a sole treatment. And if you’re experiencing new symptoms, talking with a doctor can verify the cause and adjust treatment plans to prevent medication interactions.
Omega-3 fatty acids are essential nutrients consumed through foods or supplements. There are three types of omega-3s; DHA, EPA, and ALA. Potential health benefits of omega-3s include protecting heart health, brain function, eye health, and lowering the risk of some chronic diseases.
Food sources of omega-3s include fatty fish, walnuts, flaxseed, and algae. Dietary supplements are available to help meet omega-3 needs. Talk with your healthcare provider about the potential benefits and risks of omega-3s before starting a new supplement.
A Word From Verywell
A well-balanced diet full of various vitamins, minerals, and other nutrients helps lower the risk of chronic diseases and keep a higher quality of life. Try eating fatty fish or plant-based sources a couple times a week to get the potential health benefits of omega-3s.
5 Benefits of Fish Oil
It’s becoming increasingly evident that many common chronic conditions can be prevented through modifiable lifestyle factors, but did you know that essential fatty acid deficiency is also among the top causes of chronic illness ? Essential fatty acids are termed “essential” because the body isn’t able to produce them on its own, rather, these need to come from our diet.
Fish oil, which is derived from oily fish such as salmon, sardines, tuna, and halibut, is composed primarily of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), concentrated sources of omega-3 fatty acids. Other foods such as flax seeds or borage oil, composed of alpha-linolenic acid and gamma-linolenic acid, serve as precursors for omega-3s and can contribute to the balance of essential fatty acids. Another essential fatty acid is omega-6, which ideally should be consumed in a 2:1 ratio of omega-3s to omega-6, however, the standard American diet can be nearly 10x as high in omega-6s, which can lead to inflammation as well as further omega-3 deficiency .
Several health benefits have been associated with fish oil supplementation and increased omega-3 consumption, such as decreased inflammation, decreased the risk of heart disease, decreased eczema, improvement in ADHD, anxiety, and depression, as well as preventing Alzheimer’s and dementia . Because the brain is composed of 60% fat, the nervous system relies on phospholipids as building blocks, and they’re necessary for eye and neuronal development and function, too.
1. Decreased Inflammation
Omega-3 fatty acids can promote anti-inflammatory effects as EPA is converted to anti-inflammatory prostaglandins, while omega-6s can contribute to increased inflammation, hence, a balanced ratio between the two is key. Additionally, omega-3s are known for helping decrease inflammation, which in turn can prevent blood clotting, preserve brain health, and prevent depression. They’re even capable of causing noticeably reduced levels of pain and swelling due to inflammatory conditions like arthritis . Inflammation is said to be at the root of many chronic illnesses, including cardiovascular disease. Specifically, foods that have shown to promote inflammation include, each of which can contribute to increased omega-6s:
Corn and soybean oils
Pasteurized, conventional dairy
Sugars of all kinds
Foods that help reduce inflammation and prevent oxidative stress:
Fiber-rich and antioxidant-rich foods such as flaxseed, cruciferous vegetables like Brussels sprouts, broccoli, cabbage, cauliflower and kale, dark leafy greens, artichokes, onions, peas, salad greens, mushrooms, sea vegetables and squashes
Fruits (all kinds, especially berries and citrus and other lower-glycemic fruits)
Herbs and spices, especially turmeric (curcumin) and raw garlic (also basil, chili peppers, cinnamon, curry powder, ginger, rosemary and thyme)
Legumes and beans
Healthy fats (rich in omega-3s) found in nuts, seeds, avocados, wild-caught fish, coconut oil and extra virgin olive oil
One study published in the medical journal Circulation found that people who took higher doses of fish oil for six months following the occurrence of a heart attack actually “improved their hearts’ overall functioning and also reduced biomarkers of systemic inflammation” .
2. Improved Skin & Hair Health
EPA and DHA found in fish oil can contribute to improved skin and hair health by increasing the absorption of fat-soluble vitamins necessary for the skin such as Vitamin A, E, and K. Without enough of these essential fatty acids, the skin can become dry, contributing to dandruff, eczema, thinning hair, and even sunspots. Skin health is also related to inflammation, and it’s often said that the “skin is the mirror to the gut,” reflecting the overall health of what’s happening on the inside of the body.
3. Improved Mood and Attention
Fish oil supplementation has been shown to increase nutrient and amino acid content in specific regions of the brain that relate to mood . Additionally, the European Journal of Neuroscience published a study in 2013 showing that fish oil significantly reduced anxiety-like and depression-like behavior changes induced in rats. The study also concludes that these findings indicate the importance of supplementing with fish oil at “critical periods of brain development.” 
4. Supports Brain & Nervous System Function
Essential fatty acids are necessary building blocks of the brain and central nervous system (CNS), specifically DHA. The brain is also the most energy-demanding part of the body and makes up 74% of a newborn’s total energy each day!  Having enough fat in the diet is crucial for a number of functions in the body, and of course, they’re all governed by the brain!
5. Supports Child Development
During fetal development, the baby’s nutrition comes directly from their mom, including the necessary fats, including DHA and EPA. Once the baby is born, omega-3s continue to be vital to healthy brain development and immune function. Additionally, EPA and DHA intake can help support healthy labor and delivery outcomes. During infancy, the primary source of omega-3’s and high concentrations of DHA comes primarily from breastmilk but can vary from mother to mother based on their diet and intake of omega-3’s and omega-6s. During childhood, a diet rich in omega-3s such as from wild caught salmon, egg yolks, flax seeds, walnuts, and coconut can provide these nutrients as well as supplementation with a highly concentrated fish oil.
For more information on supplementing with fish oil, speak to your provider about your options and dosing for both children and adults.
1. The Preventable Causes of Death in the United States: Comparative Risk Assessment of Dietary, Lifestyle, and Metabolic Risk Factors
2. University of Maryland Medical Center: Alternative Medicine
3. ω-3 Supplementation increases amyloid-β phagocytosis and resolvin D1 in patients with minor cognitive impairment
4. 11 Benefits of Cod Liver Oil: The Anti-Inflammatory Disease Fighter
5. Effect of Omega-3 Acid Ethyl Esters on Left Ventricular Remodeling After Acute Myocardial Infarction: The OMEGA-REMODEL Randomized Clinical Trial
6. Effects of fish oil supplementation on prefrontal metabolite concentrations in adolescents with major depressive disorder: a preliminary 1H MRS study
7. Fish oil improves anxiety‐like, depressive‐like and cognitive behaviors in olfactory bulbectomised rats
8. Docosahexaenoic Acid (DHA): An Ancient Nutrient for the Modern Human Brain/
Fish Oil: Health Benefits of Supplementing for Your Body and Brain
I’ve been dragging my feet about writing this article for so long. Not because fish oil isn’t awesome. It is! I’ve been procrastinating, telling myself, “Who doesn’t already know about the importance of fish oil? Everyone’s probably using it already.” In fact, the first time I wrote about it, it was 2009!
Obviously, I came around.
The reality is, you, the person reading this right now, might never have used fish oil before, and might have no clue how important it is for our health.
Or, perhaps you used it for a while, and when you ran out, you didn’t get a refill. You might have been taking fish oil for years, but you’re not using enough to make a difference. Or, you use it consistently but haven’t figured out how to convince your family or friends about why they need to take it too.
Whatever your situation, I’ve got you covered with this article.
What Are The Benefits of Fish Oil?
Fish oil is often advertised for its heart health benefits, but it does so much more than that (not that the health of your heart isn’t important). But I’m getting a little head of myself. Let’s start with a little primer on fish oil, omega-3s, and essential fatty acids, as there’s a lot of confusion out there.
Along with omega-6 fatty acids, omega-3s are part of a special group of fats called essential fatty acids. Like essential amino acids, essential fatty acids are nutrients you need in your diet because your body can’t make them on its own.
You don’t need to give much thought to eating enough omega-6s. They’re prevalent in the diet. Omega-3s…not so much. However, that’s not how things have always been. Long before the days of eating beef and chicken, humans ate a lot more fish, and the average diet was much more balanced with omega-6s and omega-3s.
The imbalance with which we eat those fats today contributes to numerous health problems. But it’s not just about eating less omega-6s. We need more omega-3s in the diet than we consume each day.
Plant foods like flaxseeds, walnuts, soybean, and wheat germ do contain a pretty decent amount of omega-3s, but it isn’t the ideal type of omega-3s for humans. The omega-3 fatty acid in these plants is called alpha-linolenic acid (ALA).
Some animals easily convert ALA to eicosapentaenoic acid (EPA) and docosahexaenoic (DHA). Humans do not. And it’s DHA and EPA that provide the health benefits for which fish oil is known.
We need to consume EPA and DHA directly, either by eating fatty fish or through supplementation.
Of course, if you overeat fatty fish, you do risk eating too much mercury. But high-quality fish oil is filtered to virtually eliminate mercury, so your best bet is to eat wild Alaskan salmon once in a while and take a high-quality fish oil supplement regularly.
Fish oil is part of my Foundational Five, the best supplements to support health. If I had to narrow my list down to just two supplements, it would still make the cut. You’re about to find out why.
An online survey completed by Equation Research showed that only 26 percent of Americans said they take fish oil supplements, even though 63% of the respondents said they felt their diet did not have enough omega-3 fatty acids.
1. Enhances Fat Loss
If you’re into Keto, you’ve no doubt heard people say, “eat fat and lose weight.” And while you can eat fat on Keto and drop body fat, most dietary fat doesn’t cause fat loss. It’s the removal of carbs that leads to fat loss.
However, supplementing with omega-3 fatty acids does enhance fat loss, according to research.
Animal research shows that fish oil consumption causes fat loss by stimulating the sympathetic nervous system, which releases noradrenaline. Noradrenaline stimulates brown adipose tissue, raising metabolic rate and heat production. The researchers used high-EPA fish oil at doses of up to 2.4% of the animals total calorie intake. For an adult on a 2000-calorie diet, that would equate to about 5 grams of fish oil per day.
Fish oil seems to be especially useful for reducing visceral or belly fat.
Since somebody will ask, I’ll address the fact that not all research shows fish oil affects weight loss, but it’s more a case of semantics than bad science. Some studies show that fish oil supplementation doesn’t affect body weight, while still reducing waist-to-hip ratio and visceral fat. In these studies, it’s likely that the fish oil also increased lean body mass while reducing body fat. The scale might not change significantly, but people’s body composition and health risks still do.
A small 2010 study, published in the Journal of the International Society of Sports Nutrition found the following:
Forty-four men and women supplemented with either four grams of safflower oil or four grams of fish oil. Those taking the fish oil decreased body fat and body fat percentage, increased lean body mass, and experienced a decrease in cortisol levels. Interestingly, the study participants were not instructed on diet or exercise. They were encouraged to keep their nutrition and exercise patterns the same as before the study. Noreen, et al. 2010
That isn’t an excuse to just take fish oil and avoid exercise, but it’s still impressive that the study participants saw the changes they did without any instruction on diet or exercise.
Another reason fish oil helps with fat loss is that it causes fuel partitioning. The omega-3s help your body store more calories as glycogen (stored carbohydrate) rather than as fat.
And one final reason fish oil supports fat loss: It improves satiety. If you stay full longer, you eat less.
2. Supports Healthy Lipids and Blood Glucose
Though your doctor probably still focuses his or her attention on your total and LDL cholesterol levels, the more important numbers are your triglycerides and HDL.
TRIGLYCERIDE/HDL RATIO Ratio Risk Level 1:1 or Less Optimal 2:1 Low Risk 3:1 Moderate Risk 4:1 High Risk
Supplementing with omega-3s has been shown to improve insulin sensitivity, lower triglycerides, and in some studies, improve HDL cholesterol levels.
Blood glucose and triglycerides go hand-in-hand, as you need glucose to build triglycerides. The more sugar in your diet, the higher your triglyceride levels rise. So, it’s no surprise that fish oil supplementation, which has consistently been shown to support normal triglyceride levels, also promotes healthy blood sugar levels and better insulin sensitivity.
Between EPA and DHA, it’s EPA that seems to affect triglycerides the most. And it’s been shown to be effective in adults as well as children.
Fish oil supplementation was shown to lower lipids and glucose in people with nonalcoholic fatty liver disease (NAFLD) as well. Again, not surprising, since high-carbohydrate consumption, especially consumption of fructose, is the most common cause of NAFLD. Yet, it’s rarely recommended for obese patients with metabolic syndrome who also almost always have NAFLD.
3. Increases Lean Body Mass and Strength
Research on young and old, exercising and non-exercising adults shows that the addition of fish oil to the diet enhances strength and increases lean body mass. In older adults, it can slow the loss of lean body mass, making it a great complement to a high-protein diet, amino acid supplementation, and other muscle-building supplements.
Of the two most important omega-3s, DHA and EPA, it appears EPA has the most significant effect on protein synthesis.
In research, protein synthesis increased by 30% when fish oil was combined with a sufficient amount of protein or amino acids, compared to amino acids or protein alone! These effects have been shown in healthy young, middle-aged and older men and women.
Muscle growth is a result of increased protein synthesis and/or decreased protein breakdown. The regulation of protein breakdown is controlled by a different process than protein synthesis, and evidence shows that EPA affects both sides of the equation.
4. Supports Healthy Inflammation Levels and Immune Function
Chronic inflammation is considered one of the leading causes of heart disease. Fish oil protects the heart by supporting healthy levels of inflammation.
In a study that used human blood samples, EPA+DHA intake changed the expression of 1040 genes and resulted in a decreased expression of genes involved in inflammatory and atherogenesis-related pathways.” Bouwens M, et al. 2009
Imagine that! The habit of taking fish oil every day has a positive effect on more than 1000 genes that regulate inflammation!
Those who do a lot of chronic cardio or large amounts of endurance training should make their omega-3 supplementation a top priority as they’re more likely to experience inflammation.
Inflammation is an immune response, and fish oil not only helps support normal inflammatory levels, but it’s also been shown to support the function of white blood cells.
The endocannabinoid system regulates inflammation. DHA and EPA can be metabolized into cannabinoids, making these omega-3s important for the function of your endocannabinoid system.
5. Improves Nutrient Delivery To Cells
Higher intakes of omega-3s actually change the composition of the cell membrane, allowing nutrients to flow in and out easier. The percentage of omega-3s in the cell membrane can easily be measured through a finger stick blood test.
Not only does fish oil help with nutrient delivery to the cell, but a multivitamin may also improve the assimilation of omega-3s into the cell membrane:
Taking a multivitamin along with fish oil improved the red blood cell’s ability to take up omega-3s into the cell membrane.
Just another example of why the first two supplements for most people should be a high-quality multivitamin and fish oil.
6. Supports Brain Function
DHA is passed from the mother to her unborn baby, and is crucial for brain development. It then affects brain function throughout life.
Many studies show large differences in later development when comparing babies born from mothers who supplemented with fish oil and those who did not. For example, at 2.5 years after birth, toddlers of mothers who supplemented with fish oil had significantly improved hand and eye coordination compared to toddlers of mothers who did not supplement.
The effect of DHA on brain health continues throughout life. Some research indicates DHA could ward off or slow the effects of Alzheimer’s and other cognitive diseases.
7. Additional Benefits
In addition to the benefits mentioned above, fish oil supplementation may:
Reduce psychological distress*
Reduce some symptoms of depression*
Enhance eye health*
Improve skin health*
Possibly reduce the occurrence of infant allergies if used during pregnancy*
Possibly reduce chest pain (acute coronary syndrome)*
Reduce age-related sight loss*
How Much Fish Oil Should You Eat or Take?
Most of the research showing the benefits mentioned above have participants taking one to two grams of EPA/DHA per day, or two to six fish oil softgels. Conservative recommendations for daily DHA and EPA intake range from one to four grams. Omega-3 softgels vary in their DHA and EPA content, but the label will show you how much is in there.
Lower-quality fish-oil supplements usually have about 300 mg of EPA and DHA per 1 gram softgel. Higher quality softgels often have 500-600 mg of EPA and DHA per softgel.
A typical salmon steak provides about one gram of EPA and DHA. Of course, most people do not eat fatty fish like wild Alaskan salmon every day, so supplementation should be a regular part of the diet.
What about the studies that say fish oil doesn’t work? In recent years, studies have suggested that fish oil may not reduce heart disease risk as once thought. As usual, this is a result of the types of studies used. Also, these studies have only pointed at heart health, not all the other benefits mentioned above. Observational studies haven’t shown a significant effect at reducing heart disease risk. In such a study, groups of people are asked whether they use fish oil or not. Those who say yes are put in the fish oil group and those who say no are placed in the non-fish oil group. Many of those who say “yes” to taking fish oil say yes because they have fish oil in their cupboards, not because they remember to take it every day. The other issue with many of these studies is the low dose that’s considered “using fish oil.” When just a gram of fish oil per day, especially low-quality fish oil is used, it’s unlikely to cause many positive effects.
Several years ago, my wife Vanessa was in the checkout line at the grocery store. A couple of women were in front of her. One was buying a bottle of fish oil.
The other woman saw the bottle and said, “I heard that fish oil is good for you.”
The woman holding the bottle looked at it, and then looked up at the other woman and said, “I wouldn’t know. My vet told me to get it for my dog.”
Sometimes, we take care of the nutrition needs of our pets better than we do for ourselves. Go ahead and share with your dog, but don’t miss out on the benefits of fish oil for yourself.