You may have heard that omega-3 oils are good for you and that good sources of them include fish oil and krill oil. However, there is much more to it than that.
Omega-3 oils are oils that are categorized as essential fatty acids (EFAs). EFAs includes EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid)[1]. These oils are essential because the body is unable to produce these from other sources. You can only get them through your diet. Every living cell in the body needs EFAs, they are essential for rebuilding and producing new cells and the production of chemical messengers and regulators called prostaglandins. The body cannot make EFAs so must be obtained from food sources. According to the Mayo Clinic[2], adults in the United States have lower levels of both EFAs in their bodies than Japanese people and those from other countries with a lower heart disease rate. The higher levels of EFAs are likely due to a greater amount of fish consumed in the daily diet.
Natural sources of EFAs include many vegetables, fatty fish, seeds, nuts, and fruits. Some of the best sources include flaxseed, tuna, salmon, mackerel, walnuts, egg yolks, herring, and hemp seeds.
There are two basic categories of polyunsaturated EFAs; omega-3 and omega-6. Sources of omega-6 are primarily, raw nuts, seeds and unsaturated vegetable oils such as grapeseed oil and primrose oil. There are a number of recommended sources of omega-3; among them are fish oils, flaxseed oil, grapeseed oil and primrose oil.
The daily requirement of essential fatty acids should be an amount equivalent to 10-20% of total calorific intake.
EFAs have several health benefits including:
- Supporting heart health
- Lowering triglyceride levels (types of blood fats)
- Maintaining healthy cholesterol levels
- Helping maintain healthy blood pressure
- Supporting joint and bone health
- Maintaining healthy moods
- Boosting the immune system
Both krill oil and fish oil are capable of supplying your body with helpful omega-3 fatty acids, and both have their benefits. But there are some differences between the two. Here is a comparison of krill oil vs fish oil with their pros and cons.
The Facts About Krill Oil vs Fish Oil
Krill are shrimp-like creatures which are found in oceans throughout the world. Over the past few years, this small crustacean has increased in popularity as a source of omega-3.
Fish oil has been a popular daily supplement for several decades and although krill oil has becoming more popular, it has not been as extensively studied as fish oil.
Krill oil has polyunsaturated fats have the form of phospholipids which are readily absorbed by your body[3]. Krill oil is more shelf stable than fish oil because it contains astaxanthin, an antioxidant which prevents its fats from oxidizing[4]. In spite of the fact that krill oil is thought to have similar effects on the body as fish oil, more research is needed for a thorough assessment. Cleveland clinic[5] recommends sourcing omega-3s from food or fish oil, until more studies have been conducted.
Benefits of Krill Oil vs Fish Oil
Krill oil has a number of benefits including:
- Helping maintain healthy cholesterol levels
- Maintaining a healthy inflammation response
- Balancing moods
- Protecting the health of the brain
- Supporting heart health
- Supporting menopausal health
Precautions of Krill Oil vs Fish Oil
Although krill oil is believed to be safe for most adults if used for no longer than a period of three months, there are certain circumstances in which it may not be advisable to take a krill oil supplement. These are:
- If you are pregnant or nursing
- If you have any seafood allergies
- If you have a scheduled surgery, (because it can reduce blood clotting)
- If you are taking any medications that slow blood clotting
- If you are using the weight loss drug Orlistat, as krill interacts with this medication
The Facts About Fish Oil
Fish oil is a rich source of omega-3 fatty acids and has a higher concentration of the two fatty acids DHA and EPA than krill oil[6]. Unlike other omega-3 oils like flaxseed and krill oil, it also has a high vitamin D content. It, therefore, helps reduce cholesterol, support heart health as well as joint and bone health and to stabilize mood.
Sources include cold-water oily fish such as sardines, anchovies, mackerel, herring and salmon. One significant concern about fish oilis that it is high in vitamin A. Too much vitamin A can cause weakened bones[7]. It may be beneficial to choose a supplement in which the vitamin A content has been reduced. The supplement facts label on each bottle of fish oil should tell you how much Vitamin A it has. Another concern about fish oil is that it may contain toxins or contaminants from the environment, such as heavy metals or PCBs since fish are higher up in the food chain and heavy metals will bioaccumulate accordingly.
Benefits of Fish Oil
The numerous benefits of fish oil include:
- Supporting cholesterol level and heart health
- Helping reduce the build-up of plaque in the arteries
- Balancing blood pressure
- Supporting stable moods
- Protecting eye health
- Supporting a healthy inflammatory response
Precautions of Fish Oil
Because fish oil may lower the blood pressure, it should not be taken along with other blood pressure reducing medications because it may cause blood pressure to fall too low[9].
As little is known about the effects of fish oil on pregnancy and nursing, it should be avoided during these times.
You should not take fish oil if you are also taking medication to slow blood clotting as the two may interact.
Supplementation With EFAs
Krill Supplements: A typical krill oil supplement contains 1,000mg of krill oil, which contains 120 mg DHA and 180 mg EPA[10]. Recommended daily supplementation seems to differ widely between 1-3 grams per day depending on your body weight.
Fish Oil Supplements: While the American Heart Association recommends healthy adults consume two servings of fatty fish per week, they do not have any specific fish oil recommendations. Their recommendations for fish consumption equates to between 1,500 and 3,500 mg of EPA and DHA[11] per week.
Final Thoughts on Krill Oil vs Fish Oil
With these differences of krill oil vs fish oil and how do you decide which one to use? Omega-3s are vital for your normal bodily functions. Clinical research offers mixed advice about how to get them, and exactly how much you need on a daily basis. Although eating sustainable seafood twice a week should provide sufficient EFAs, it’s no guarantee. This is because it’s difficult to ascertain how much omega-3 is present in the fish you eat.
The American Heart Association has recommendations for the consumption of fish in healthy adults but does not have recommendations for krill oil or fish oil. Based on their recommendations for fish consumption containing between 1,500-3,500 mg of EPA and DHA per week, an equivalent amount of omega-3 oil from supplements is between 215-500mg of EPA and DHA per day.
The medical community also has accepted fish oil recommendations for patients with hypertriglyceridemia (high blood triglyceride levels). For patients with hypertriglyceridemia doctors commonly recommend taking 4 grams of prescription strength fish oil (Lovaza) daily.[12] Prescription strength fish oils have > 85% omega-3 oils which is approximately 1,860mg of EPA and 1,500mg of DHA daily[13]. Most over the counter fish oils only have 30-50% omega-3 oils so you will need to take more pills to get the same dose.
Whichever supplement you choose, make sure it is made from safe ingredients and that it is manufactured in an FDA inspected facility.
Also make sure that the fish oil you choose is molecularly distilled to remove heavy metals, toxins, PCBs, mercury, and dioxins.
If you are concerned about experiencing embarrassing fishy burps, simply choose a fish oil supplement with an enteric coating to eliminate the problem. Enteric coatings can be made of all sorts of materials. Make sure your fish oil utilizes a phthalate-free enteric coating. Phthalates are known hormone-disrupting chemicals.
In summary, most professional organizations recommend fish oil to support cardiovascular health. Prescription strength fish oils are available through your doctor. The strength of over-the-counter fish oil supplements varies and so does the quality. If you decide to go with an over-the-counter supplement make sure the ingredients are pure, that the anti-fishy burp enteric coating does not have phthalates, and the fish oil itself is molecularly purified to remove PCBs, mercury, toxins, heavy metals, and dioxins.
[1] http://drhoffman.com/article/what-are-epadha-13/
[2] https://www.mayoclinic.org/drugs-supplements-fish-oil/art-20364810
[3] https://www.nutraingredients-usa.com/Article/2013/12/10/Is-krill-more-effective-than-fish-oil-for-raising-the-omega-3-index
[4] http://www.nutritionaloutlook.com/articles/why-krill-oil-more-stable-fish-oil
[5] https://my.clevelandclinic.org/health/articles/omega-3-fatty-acids-heart-health
[6] https://www.healthline.com/health/food-nutrition/krill-oil-vs-fish-oil
[7] https://www.bones.nih.gov/health-info/bone/bone-health/nutrition/vitamin-and-bone-health
[8] https://www.consumerlab.com/news/ReviewofFishOilandOmega-3SupplmentsbyConsumerLab.com/8_22_2012/
[9] https://medlineplus.gov/druginfo/natural/1040.html
[10] https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
[11] http://www.heart.org/HEARTORG/HealthyLiving/HealthyEating/HealthyDietGoals/Fish-and-Omega-3-Fatty-Acids_UCM_303248_Article.jsp
[12] https://www.uptodate.com/contents/hypertriglyceridemia
[13] https://www.rxlist.com/lovaza-drug.htm
About the Author:
Dr. Bryan Do, D.O. is an osteopathic physician whose research interests include gastroenterology, immunology, and dermatology. He is particularly interested in the role of probiotics in the gut-brain-skin axis and has written many articles on the topic. He graduated from University of California, Los Angeles (UCLA) before graduating from Marian University College of Osteopathic Medicine in Indianapolis, Indiana and becoming a Doctor of Osteopathic Medicine. Osteopathic physicians are taught to take a holistic approach to medicine and to consider mind, body, and spirit when treating a patient. Osteopathic physicians receive training in Osteopathic Manipulative Medicine (OMM) in addition to the standard rigorous medical school curriculum. Both physicians with a Doctor of Osteopathic Medicine (D.O.) degree as well as a Doctor of Medicine (M.D.) can practice medicine.