Everything You Need to Know about Fish Oil

You probably know by now that the omega-3 fatty acids in fish are good for you: They’re excellent for your ticker, a boon to brain health and help maintain visual acuity. The American Heart Association and the World Health Organization both recommend regular fish consumption for its fatty acid content. And our very own in-house nutrition guru, Jonny Bowden, PhD, calls fish oil “one of the most anti-inflammatory compounds in the world.” If you are not getting at least two servings of fish per week, have a condition such as arthritis or heart disease, or are at risk for macular degeneration, you might consider taking a supplement.

Not all fish oil supplements are created equal, however; they vary widely by type, quality as well as balance of fatty acids. Choosing a fish oil doesn’t have to be rocket science, though. We’ve broken down the varieties you’re most likely to see in the supplement aisle and five key things to consider when selecting a brand for you.

1. Look at the variety of fish and how it’s sourced. When a product is labeled fish oil, it’s typically a blend of more than one fish — usually smaller fish such as anchovies, sardines and mackerel. A fish oil blend is affordable and has the most research around its benefits, but it’s not the only option.

Cod liver oil contains vitamins A and D in addition to omega-3 fatty acids that support brain health. Krill oil has gained traction in recent years both for its sustainability and its bioavailability, according to Josh Axe, DNM, CNS, DC, co-founder of Ancient Nutrition and founder of draxe.com. “Krill oil is considered one of the most sustainable sources of omega-3 fatty acids, as Atlantic krill are among the most abundant animal species in the world,” explains Dr. Axe. He notes that there are limited studies on bioavailability, but a 2015 review of 14 studies concluded that key essential fatty acids are better absorbed from krill oil when compared to fish oil. Another variety you might see on the shelves is wild salmon oil, also rich in omega-3 fatty acids, and since it’s sourced from wild — not farmed — salmon, it’s considered to be more sustainable than some other varieties.

And while krill and wild salmon are often noted to be sustainably sourced, it doesn’t mean that regular fish oil is not. Look for varieties that state they are sustainably caught, or denote a geographic location where sustainable fishing is mandated, such as Norwegian- or Alaskan-caught fish.

2. Know the difference between high EPA and DHA formulas. The two major fatty acids found in fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — and while they both provide benefits, you may choose a different ratio of one over the other depending on your needs. Laurel Sterling, RD, CDN, national educator for Carlson Labs, recommends opting for a high-EPA formulation for supporting cardiovascular, joint and skin health. A high-DHA formulation, she suggests, typically would be suited to women who are pregnant or breastfeeding and for children’s brain and vision development. It could also be utilized for supporting cognitive function, nerve health and for vision. Remember that most fish oils tend to have more naturally occurring EPA than DHA, but most companies now offer formulations that have higher concentrations of one or the other.

3. Review third-party ratings. Quality is perhaps the most important consideration when choosing a fish oil­ – a lower-quality brand that uses fillers or additives or that may not be at peak freshness may actually do more harm than good. “Many fish oils on the market today are contaminated with dangerous compounds such as mercury, pesticide residues and hydrogenated oils,” according to Dr. Axe. “They can also go rancid quickly, which can cause an unpleasant taste and can even be harmful to your health.” But you don’t have to weed through brands for freshness and purity yourself – there are third-party organizations that do the legwork for you. The International Fish Oil Standards Program (IFOS), for example, rates brands on a five-star system and takes into consideration things like omega-3 concentration, oxidation (freshness) and content of heavy metals and other toxins like PCBs and dioxins. We recommend using a brand with a five-star rating.

4. Get the dosage right. Keep in mind that if you’re taking fish oil for a specific condition, you’ll likely need a higher dose than if you’re taking it for general health. According to Sterling, a good place to start is 1 to 2 grams per day of omega-3 fatty acids, 1 gram for general health and 2 grams for specific health concerns such as an inflammatory or cardiovascular condition. There are some cases where, she notes, you might even go as high as 4 grams, such as in the case of treating high triglyceride levels, but always check with your doctor when you are considering higher doses, especially if you’re on other medications such as blood thinners. Note that these dosages are for combined EPA, DHA and other omega-3s, so when you’re looking at the label, add up the amount of EPA, DHA and other omega-3s for the total combined amount in the product.

5. Consider the full package. Because fish oils can easily go rancid, Dr. Axe recommends opting for a variety that contains antioxidants to keep the product fresh, such as astaxanthin, which is naturally occurring in both krill and wild salmon oil. “This is incredibly important because it helps stabilize the oil and keeps it from going rancid to ensure your product is safe and healthy,” says Dr. Axe. While a regular fish oil blend may not have a naturally occurring antioxidant such as astaxanthin, many companies will add an antioxidant or a blend of antioxidants to preserve the oil. And don’t forget that when it comes to any supplement, you’ll want to consider not only what’s in it, but also what’s not in it: Fillers, additives or allergens such as gluten and soy should all be avoided and could be an indication of a lower-quality product, according to Dr. Axe.

Liquid versus caps? Since exposure to air can cause oxidation in delicate oils, liquid formulas are more prone to rancidity, so if using one, make sure to store it in the refrigerator, especially after opening. Capsules, since they are not exposed to air, tend to stay fresher for longer.

Avoid a fishy aftertaste. Try taking your fish oil with a meal rather than on an empty stomach. If that’s not enough, Sterling recommends choosing capsules and storing them in the freezer – she says that this causes the capsules to release further down in the gastrointestinal tract, so it’s less likely to repeat on you.

You don’t eat fish. So now what? Algae oil is a good source of DHA and is a great option for vegetarians and vegans. In fact, fish get their omega-3s from eating algae, too!