Taking a supplement is often the best way to get omega-3 fatty acids that are vital for good health, and knowing what to look for is the key to finding a product that delivers what you need.
The ideal source of omega-3 fatty acids is fresh, fatty fish, but most people don’t eat enough to get adequate amounts.
Fish oil supplements have grown in popularity as the benefits of omega-3 fatty acids become more widely known; many different forms are available, and choosing the right one can be a confusing proposition.
We’ll take a look here at the types of omega-3 supplements, which ones are easiest for the body to absorb, how to decipher labeling information, as well as options for vegetarians and vegans.
When you eat whole, fatty fish, omega-3 fatty acids occur as triglycerides, phospholipids and free fatty acids.
Fish oils containing omega-3 fatty acids are available in two forms: natural and processed.
- Conventional fish oil offers omega-3 fatty acids primarily in the form of triglycerides.
- Fish oils that have been processed are changed into ethyl esters; these aren’t found in nature. Processing can purify the oils of contaminants as well as concentrating nutrients.
- The term “reformed triglycerides” indicates that ethyl esters have been changed back into triglycerides.
Studies indicate that the free fatty acids found in whole foods like fish are absorbed by the body at rates about 50% higher than supplements containing triglycerides, and triglyceride absorption runs 50% more than ethyl ester absorption. (3, 4, 5)
Natural fish oil is triglycerides taken from fish tissue, and is basically the closest match to what you would get from eating fish.
Vitamins A and D are also present, and any product that has been fermented will also contain vitamin K2.
Examples of natural fish oils are cod liver oil, sardine oil and salmon oil. Usually sold in a liquid preparation, these oils resist oxidation better than processed oils.
The fats in processed fish oils have been converted into ethyl esters, and are purified, concentrated or both. DHA and EPA levels may be higher in processed oils, and PCBs, mercury and other contaminants have been removed.
Processed fish oils can deliver between 50% and 90% DHA and/or EFA; these supplements are usually reasonably priced and make up most of the omega-3 supplements on the market.
Ethyl esters are not as well absorbed by the body, but some products have been further processed back into a form of synthetic triglyceride, which is better absorbed than ethyl esters. (8)
These re-formed triglycerides, also referred to as re-esterified, are pricey, making up a small percentage of supplements sold.
Sources of Omega-3 Supplements
Omega-3 supplements can be made from a variety of sources, including fish, shellfish, sea mammals, algae and other plants.
These are the five most common supplements you’ll find on the market:
- Krill Oil
Extracted from a small creature similar to shrimp, the omega-3 content of krill oil is in both phospholipid and triglyceride form. (9)
Astaxanthin, a powerful antioxidant naturally occurring in krill oil, helps protect against oxidation. (12) These tiny creatures don’t live long, so toxin accumulation in their bodies is minimal; this means purification isn’t necessary, and it’s rare to find krill oil in ethyl ester form.
- Green-Lipped Mussel Oil
This mussel is native to New Zealand, and oil from this source is considered an environmentally friendly choice for omega-3 supplements.
The oils usually occur in the form of free fatty acids and triglycerides, and deliver eicosatetraenoic acid (ETA) in addition to DHA and EPA.
- Mammalian Oil
Derived from seal blubber, the omega-3 oils in this type of supplement are natural triglycerides consisting of EPA, DHA, docosapentaenoic acid (DPA), which is also a rare fatty acid with several known health benefits. (15)
Another plus in choosing mammalian oil is its very low level of omega-6 fatty acids, which can promote a more beneficial ratio between omega-3 and omega-6 fatty acid levels.
- Alpha-lipoic Acid Oil
This plant source of omega-3 fatty acids is especially abundant in hemp seed, flax seed and chia seed. The drawback is that ALA isn’t active in humans, and needs to be converted into DHA or EPA to be utilized.
Oils from plants are also much higher in omega-6 fatty acids, which can lead to unfavorable ratios of omega-6 and omega-3 fatty acids.
- Algal Oil
The DHA and EPA contained in marine algae are triglyceride sources of omega-3s, and algal oil is one of the most concentrated sources available, higher even than fish oils.
Algae is the original source of EPA and DHA found in fish; small fish eat algae, and in turn are eaten by larger fish, with fatty acids moving up the food chain in that manner.
Important minerals, including iodine, can also be found in algal oil, and it’s a great source of omega-3s for vegetarians and vegans. (18)
Besides being free of contaminants, algal oil is an environmentally responsible choice and could help to meet the growing need for omega-3 supplementation worldwide.
Consumers usually prefer taking omega-3 supplements in capsules because they are tasteless and easy to swallow; enteric-coated capsules are also available, and the coating protects contents from being released into the digestive system until it reaches the small intestine.
This prevents fish-flavored burps, but can also hide the smell of rancid oils. Opening a capsule now and then can tip you off if the oil has gone rancid.
When looking for a good supplement, make certain it has EPA and DHA, which are the most important types of omega-3s. Labels list total amount of fish oil, but check amounts of EPA and DHA in nutritional facts so you’ll know how much of these are in each capsule.
Ethel esters are the least desirable form of omega-3s, so choose a supplement that lists free fatty acids (FFA), triglycerides (TG), reformed triglycerides (rTG), or phospholipids (PLs).
Products with a stamp proclaiming they adhere to the GOED standard for purity and/or “tested by a third party” are more likely to contain what they have listed on labels.
Sustainability and freshness are also considerations. Products certified by the Environmental Defense Fund (or similar organizations) are a good bet, added antioxidants like vitamin E can help keep fish oils fresh longer.
Always check for “best by” dates, and don’t stock up on this type of supplement because they lose potency over time, as well as becoming potentially harmful if rancid.
Animal-based omega-3 supplements will generally deliver more bio-available fatty acids, with algol oil being the notable exception.
Taking supplements with a meal containing generous quantities of fat will aid in absorption. (19)
Summary: For those who cannot include fatty fish regularly in their diets, adding a good quality omega-3 supplement to your health plan can provide important health benefits; choose supplements carefully to make certain you get reasonable quantities of fresh oils for the money you spend.