Omega-3 Fatty Acids: What You Need to Know
Many people – especially those consuming Western diets – don’t get enough omega-3 fatty acids, including the essential fatty acids DHA and EPA. Omega-3s are important for maintaining a healthy brain and cardiovascular system, reducing inflammation, cutting the risk of a heart attack, lowering the blood pressure, and many other important physiological functions. The good news is that taking a high-quality supplement that’s easily absorbed by the body can boost your omega-3 levels significantly and may improve your health.
Remember the following when it comes to choosing omega-3s:
- People who get enough omega-3s (specifically DHA and EPA) tend to have better long-term health and get fewer diseases over time, all else being equal.
- Unfortunately, our bodies can’t produce omega-3s. As a result, we must get them from plant and animal products that contain them. That means eating fish at least twice a week or taking supplements that contain fish oil, krill oil, or algal oil.
- Fat helps with absorption of all fat-soluble nutrients, including omega-3s. That means eating fats when taking omega-3s is a good idea for maximum benefit and proper absorption.
- Aim for max 2 grams of omega-3s per day from supplements.
- Not all omega 3 supplements are equally absorbable by the body – look for fish oil in triglyceride form. When taking krill oil, note that since it is not concentrated, you may need to take more of it to get the same level of DHA and EPA as fish oil. Algal oil tends to be more concentrated than krill and has higher levels of DHA and low levels of EPA.
- Finally, be sure to refrigerate fish oil and algal oil. Do not refrigerate krill oil as this will cause it to separate and not absorb as well when you take it.
Most people are likely be best served by taking both, alternating:
+ A high-quality and pure fish oil with concentrated omega-3s – high DHA and EPA content – in best-absorbed triglyceride form
+ A krill oil high in astaxanthin, a powerful antioxidant
A high-quality algal oil is a less-researched but excellent option for people with seafood allergies, vegans, and vegetarians.
Overview of Omega 3s – DHA, EPA, and ALA
Omega-3 is a type of polyunsaturated fatty acid that is needed for the body to maintain lipids, one of the four major types of macromolecules found in humans. Maintaining lipids is important for optimal health and preventing disease. In particular, omega-3s seem to improve cardiovascular function by decreasing inflammation and reducing incidents of peripheral artery disease and major coronary events like heart attacks. Studies also show that consuming omega-3s and other fatty acids can reduce the risk of cancer, arthritis, hypertension, diabetes, and neurological problems, as well as improve brain and eye function. Omega 3s are also vital for proper fetal development, and supplementation by pregnant women correlates with decreased unwanted immune responses in infants, such as allergies. Omega 3s accomplish these things in part by affecting gene expression.[1, 2, 3, 4]
Omega 3s come in three types: docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and alpha-linolenic acid (ALA). Marine organisms like fatty fish, krill, and algae contain DHA and EPA, whereas ALA is found in plants and nuts like soybeans, flaxseed, walnuts, and canola oil. People can’t use ALA directly and have to turn it into DHA or EPA, which the human body does inefficiently; only about 10% of plant-based ALA molecules are metabolized into the other types of omega-3s.
Functions and Health Benefits of Omega 3s
The primary job of omega-3 fatty acids is to regulate levels of various forms of lipids in the brain, heart, and other important parts of the body. Omega-3s can increase the HDL (“good cholesterol”), decrease triglycerides, and keep blood pressure at normal levels.
EPA is used throughout the body, whereas DHA is mostly found in the eyes and the brain. The human brain is made up of about 60% fat, half of which is DHA. DHA is also found in the retinas, and studies suggest that Omega 3s are important for healthy retina functioning. Because EPA and DHA have similar molecular structures, EPA can be converted into DHA through a biological pathway called Sprecher’s shunt if the brain, eyes, or other parts of the body need more DHA.
Omega 3s help regulate many processes throughout the body and have been shown to help prevent a variety of diseases and conditions, in large part by reducing inflammation. Studies also show that omega-3s reduce triglycerides, lower total cholesterol, slow the development of blood clots, and reduce high blood pressure, all of which are risk factors for heart disease, heart attack, and stroke.[6, 7, 8, 9, 10] Having good levels of omega 3 may help prevent diabetes by lowering triglycerides and raising HDL cholesterol, may help relieve joint pain associated with rheumatoid arthritis and other inflammatory diseases, and may help increases calcium levels and prevent osteoporosis. Studies also suggest that eating foods rich in omega-3s may help prevent or slow the progression of colon, breast, and prostate cancer. In addition, Omega 3s play a role in hormones secretion, muscle activity regulation, cell division, and blood clotting.
The brain also benefits from DHA in a many ways. In particular, DHA can help fight depression and maintain, or even improve, cognitive functioning.[6, 12, 13] The synapses between neurons contain DHA, indicating that having a sufficient amount of this type of omega-3 is crucial for neurotransmission.[5, 6, 14] As a result, research indicates that abnormally low levels could be a contributor to Alzheimer’s disease and other forms of dementia.[3, 5, 15, 16]
Another important function of omega-3s is to control how genes are expressed. This has a big impact on long-term health. Omega-3s help the body produce energy by undergoing β-oxidation, which splits carbon atoms and releases CO2. This in turn helps produce adenosine triphosphate (ATP), an organic chemical involved with many cellular processes.
Omega-3s are digested in the small intestine, where they pass into the bloodstream and are processed via Sprecher’s shunt. ALA can only be converted into the essential fatty acids EPA and DHA at a rate of about 10 percent. In addition, EPA molecules can be converted into DHA molecules.[14, 17]
Omega 3 Deficiency and Insufficiency
Most Americans currently don’t get enough omega-3s in their diet, mainly because consumption of fatty fish – which is high in omega 3s – has declined significantly over the past century. Many of the fish we do eat are farmed, and farmed fish contain a lot less DHA and EPA than wild fish because of what they are fed. In addition, many farmed fish contain high levels of mercury. Eating fish contaminated with mercury is a particular concern for women who may become pregnant.
At the same time, Americans and other people who consume a typical American diet may be getting too much of another fatty acid called omega-6, which is found in vegetable oils like corn and canola oil. Health practitioners are still not sure about the exact impact of this on health but it’s theorized that the ratio of omega 3 to omega 6 in the diet and body may be important for good health. The typical American diet has 14 to 25 times as many omega-6 fatty acids as omega-3s, which is potentially too high. Omega-6 fatty acids are needed by the body, but too much of them can interfere with the function and absorption of Omega-3s. Having too many omega 6s is theorized to cause inflammation, cardiovascular disease, and other health issues.[1, 12] A related problem is that many vegetable oils contain trans fats, which raise low-density lipoproteins (LDL, or “bad”, cholesterol) and triglycerides.[12, 15] Vegans and vegetarians particularly need to watch their omega-3 levels because they don’t eat fish, the primary food source of EPA and DHA in most people’s diets.
Symptoms of a clinical omega 3 deficiency can include fatigue, memory difficulties, dry skin, heart conditions, circulation problems, abrupt changes in mood, and even depression. Insufficiency of DHA and EPA may be asymptomatic but still have far-reaching negative effects on the body and brain, especially in the longer term.
Getting Omega-3s: Food and Supplement Options
Most natural EPA and DHA comes from fatty fish such as tuna, salmon, and mackerel. To get enough EPA and DHA from food sources, most experts recommend eating fatty fish at least twice a week. Wild fish are preferable to farmed fish because the latter contain fewer omega-3s due to the vegetable oil in their feed. Wild salmon have been found to have a ratio of omega-3s to omega-6s of 14.5, whereas the ratio for farmed salmon can be as low as 1.5. When eating fish, remember that it can be contaminated with heavy metals and other toxins. This is especially true for large fish such as shark, swordfish, tilefish, and king mackerel, which should generally be avoided. [21, 22]
Certain plant-derived products such as olives, soybeans, walnuts, pumpkin seeds, flaxseed, and canola oil contain ALA, a form of omega-3. Beef has low levels of omega 3s, mostly as ALA, with grass-fed beef containing significantly more than grain-fed beef. Although only a small amount of ALA can be converted into DHA and EPA via Sprecher’s shunt, consuming plant-based omega-3 is still recommended, especially for vegetarians who will not be intaking omega-3 from fish. It should be noted that women have higher ability than men to convert ALA to DHA. There are also genetic differences related to an individual’s ability to convert the different omega 3 forms into what the body needs.
Most people won’t have access to enough wild-caught, uncontaminated, fatty fish to get optimal DHA and EPA levels from food. Many choose to take supplements containing fish oil, krill oil, and algal oil. Fish oil should be in triglyceride form for best absorption, sourced from small wild fish, and be processed by a high-quality producer. Krill oil is already in the highly-absorbable phospholipid form and contains astaxanthin, which is excellent for health in its own right.[1, 23, 24] Krill oil is less concentrated however and contains less omega-3 fatty acids. Algal oil is a great option for those with seafood allergies or determined to avoid animal-sources while still getting the omega-3s that are necessary for long term health.
Getting Omega 3 Fatty Acids from Fish Oil Supplements
Fish oils are naturally mostly in the triglyceride form, whereas the fish oil in supplements are most often in the less-absorbable ethyl ester form. One can purchase fish oil in triglyceride form, although it is more expensive because it has to go through additional processing. The added cost is value worth it, however, because fish oil in the triglyceride form is much more absorbable — and goes rancid much more slowly — than the ethyl ester form.
When choosing a fish oil, look for a high-quality manufacturer that uses smaller wild fish as a source for the oil. Fish and krill (see below) don’t produce DHA and EPA on their own. Rather, DHA and EPA are created by microalgae that are consumed by phytoplankton, which in turn are eaten by the fish and krill. All currently marketed fish oil supplements contain more EPA than DHA, although the exact amounts — and their purity — vary by product.
Fish oil supplements have varying amounts of EPA and DHA, and differ in purity and how easily they are absorbed. Fish oil supplements in the not-well-absorbed ethyl ester form are the most common, so assume a given supplement is ethyl ester unless otherwise indicated. Ethyl ester fish oil supplements commonly contain about 180 mg of EPA and 120 mg of DHA, although again this will vary by brand, as some are more concentrated than this.
If you’re one of the many people who don’t get enough omega-3s from your diet, consider taking a fish oil supplement, which can provide enough DHA and EPA to make up for dietary deficiencies. Look for the re-esterified triglyceride form of fish oil as it is readily absorbed. Look for a product that is well-filtered and concentrated when supplied by a high-quality manufacturer, so it provides the most value for the money. Some fish oil manufacturers purify the fish oil and then independently test the final product. Choosing a product made by a high-quality manufacturer is very important to avoid contaminants.
Getting Omega 3 Fatty Acids from Krill Oil Supplements
Antarctic krill, a shrimp-like crustacean, are used to produce krill oil. Although the health benefits of krill oil have not been studied as much as those of fish oil, existing research indicates that many of the benefits are similar. However, krill oil is not concentrated like fish oil, and as a result provides less DHA and EPA per pill or serving. Thus, people who want to increase their high-benefit omega-3 DHA and EPA consumption, triglyceride-form fish oil is a better choice.
However, the EPA and DHA molecules in krill oil might be more easily absorbed by the body than those of fish oil. That’s because EPA and DHA in krill oil are bonded to phospholipids, and those in fish oil are bonded to triglycerides.[8, 9, 27] Phospholipids are more absorbable because they dissolve in water, whereas those in fish oil don’t. That means in order to get the most benefit from fish oil, it must be consumed with fatty foods; no such limitation applies to krill oil.[11, 14, 28]
Krill oil also naturally contains astaxanthin, which is a powerful antioxidant. Astaxanthin is the red pigment, a carotenoid, that gives some marine organisms their red color. Research studies for its health effects on the body are highly promising.[23, 24] Preliminary results indicate that astaxanthin reduces inflammation, reduces oxidative stress, protects cells, and promotes heart and brain health.[29, 30, 31] There are also very promising studies that indicate that it may also help prevent cancer and generally improve improves immune function.[32, 33, 34] Astaxanthin has also been demonstrated to help with eye health, specifically macular degeneration.[35, 36]
In krill oil, astaxanthin helps to keep omega-3s from breaking down and going rancid, and has been shown to generally reduce oxidative stress and inflammation.
Lastly, because krill are easier to harvest than many fish and fish stocks worldwide have been decimated by overfishing, some believe that krill oil is a more sustainable source of omega-3s than fish oil. However, more studies are needed to understand how the omega-3s in krill oil are absorbed and exactly what health benefits they have.
Getting Omega 3 Fatty Acids from Algal Oil Supplements
Algal oil contains significant amounts of DHA and small amounts of EPA. As a result, it’s a great option for vegetarians, vegans, and people allergic to seafood. It’s been noted that these people find it especially hard to get enough of these essential fatty acids in their diets. Algal oil supplementation is considered generally safe and well-tolerated.
Although research on the specific health benefits of algal oil is limited, some studies show that the DHA in algal oil has anti-inflammatory properties and other benefits like fish and krill oil omega-3s. The DHA in algal oil has been found to be just as absorbable as that in fish, and algal oil is also free of the contaminants found in fish, especially those that are farmed. Algae used to source algal oil is grown in laboratory conditions, never actually touching sea water. If a high-quality growing and manufacturing facility is used, algal oil produced in this way has less exposure to potential contaminants. EPA and DHA in algal oil are in triglyceride form and thus well-absorbed by the body.
Another advantage of algal oil is that it can be obtained more sustainably than fish oil, given that wild fisheries are declining worldwide and aquaculture causes pollution and other environmental problems.
Considerations for Omega 3 Supplements and Contraindications
According to the National Heart Association, one should try to eat fatty fish at least twice a week, which provides approximately 400-500 mg per week of EPA and DHA.[3, 16] Americans consume only 10 to 20 mg of EPA and DHA daily, or about 70-140 mg weekly, the Mayo Clinic estimates. Existing human research trials indicate that the health benefits of DHA and EPA generally increase proportionally with amount consumed, with the upper limit at 2,000 mg per day.
Thus, it is safe to consume up to 2,0000 mg of DHA + EPA daily from a high-quality, well-absorbed fish, krill, or algal oil. If consuming a fish oil supplement, eating fat along with it will aid in absorption. According to the Food and Drug Administration, no one should consume more than 3000 mg of omega-3 fatty acids in one day from food and supplements combined, and no more than 2000 mg of that amount should come from supplements.
Taking too much omega-3 can cause a variety of side effects, including burping, a bloated stomach, diarrhea, and gas. The same problems can be caused by specific ingredients in a given supplement, so a smaller dose or different supplement may be the solution if this occurs to you. Talk to your doctor if the side effects don’t go away or if more serious side effects like bleeding or changes in blood pressure or blood sugar occur.
Medications that affect blood pressure, blood sugar, or cholesterol, or increase the risk of bleeding, as well as nonsteroidal anti-inflammatory drugs, can interact with omega-3 supplements in undesirable ways. Individuals taking these medications should always consult with a doctor before beginning omega-3 supplementation to discuss proper dosage.
How to Choose What is Right For You
Omega-3 fatty acids, especially DHA and EPA, are vital for long-term well being. The current best bet to get maximum health benefits is to take fish oil and krill oil at alternating times. This way you get the best of both worlds — high omega-3 content from the concentrated fish oil and high antioxidant action from the astaxanthin in krill.
Krill oil supplements usually contain less EPA and DHA than fish oil because the fatty acids in krill oil cannot be concentrated. However, the body absorbs omega-3s in krill oil very efficiently and the astaxanthin contained within is very promising as a health-promoting substance. Krill oil is a great addition to almost everyone’s supplement regimen for this reason. Make sure to get your krill oil from a highly-reputable source. Exact amounts of DHA, EPA, and astaxanthin contained per serving of krill oil should be listed on the label. The brand should undergo third-party independent testing and review by consumer-watchdog agencies.
To get the health benefits of the omega-3s, triglyceride-form fish oil is the best option due to its concentrated DHA and EPA content. Choose a high-quality brand of fish-oil supplement to ensure that it hasn’t been contaminated by heavy metals or other toxins. Manufacturers should always certify that their products are free from mercury, lead, and cadmium, and these assertions should be backed up by third-party testing. If possible, buy the re-esterified triglyceride form of fish oil because it is well-absorbed, highly filtered and concentrated, and does not go rancid (oxidize) as quickly as the ethyl ester form. As a result, although it costs a bit more, it is a better value when you consider DHA and EPA amount absorbed per dollar paid.
Some omega 3 supplements are also in phospholipid form but sourced from fish roe — these are very well absorbed but will not contain astaxanthin. People with seafood allergies, vegans, and vegetarians, should consider DHA-containing algal oil supplements instead of fish oil and krill oil.