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If you want to improve your overall health, performance, and recovery, then you might consider adding more heart-healthy fats like omega-3 fatty acids to your diet. After all, research suggests omega-3s have the potential to improve health in a number of ways, including lowering heart disease risk and helping to manage mental health conditions.
Commonly found in foods such as fish and nuts, these healthy fats can also be found in fish oil supplements, which is one way you can up your daily intake of these nutrients.
But does this mean fish oil supplements are the best choice for your health and performance? Read on to find out what experts and research have to say about the pros and cons of fish oil.
What are fish oil supplements?
Fish oil supplements include two out of three kinds of omega-3 fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—and usually come in the form of a liquid, capsule, or pill.
EPA and DHA are essential fats that your body needs but can’t necessarily make on its own. That is, unless you consume the third form of omega-3, alpha-linolenic acid (ALA) which is found in nuts, flaxseeds, chia seeds, and some oils, but not in fish oil supplements. If you consume enough of this nutrient, according to the National Institutes of Health, then your body can convert it into small amounts of EPA and DHA. Meanwhile, you can also get EPA and DHA in fish, seafood, and supplements.
The caveat about ALA converting to EPA and DHA in your body is that researchers don’t understand exactly how much ALA your body can convert, Jessica Garay, assistant professor in the Department of Nutrition and Food Studies at Syracuse University tells Bicycling. Based on the available research, it falls somewhere between 5 and 10 percent, she says.
“You can consume omega-3’s from non-fish sources like walnuts and flax seeds. But we can’t assume that that’s going to then meet our daily need for EPA and DHA separately," Garay adds.
And you need these nutrients regularly, because they play such a vital role in your body including in your heart, lungs, immune system, and endocrine system (responsible for hormones).
The other issue is that, according to the Dietary Guidelines for Americans, nearly 90 percent of U.S. adults don’t consume enough seafood, and a little more than 50 percent don’t consume enough nuts—two key sources of omega-3s—which is where fish oil supplements may come into play.
Are there any benefits associated with fish oil supplements?
Originally, Garay explains, researchers began to study omega-3 fatty acids because of the potential benefits it posed to heart disease. “But now we see omega-3s being recommended for all sorts of conditions beyond heart disease,” she says. “Research has shown that consuming omega-3 fatty acids provide anti-inflammatory benefits to the body which can help prevent or manage diseases like diabetes, arthritis, and even cognitive conditions like Alzheimer’s.”
In terms of cardiovascular health, researchers of a meta-analysis published in the Journal of the American Heart Association found the optimal intake of omega-3 fatty acids for lowering blood pressure is likely between 2 and 3 grams a day—above 3 grams for those at higher risk for cardiovascular disease.
However, researchers included a mixture of studies in this analysis. Some of the research examined both the combination of EPA and DHA, as well as isolated forms of these omega-3s, and other research included in the analysis looked at both dietary intake and supplementation. Bottom line: The researchers of this study didn’t champion either food or supplements as superior.
Also, a 2021 meta-analysis published in eClinicalMedicine suggests EPA has a greater impact on decreasing cardiovascular risk than the combination of EPA and DHA.
Other research points to potential benefits of fish oil supplements for athletic performance. A review published in Nutrients in 2020 states that evidence suggests there are potential benefits of omega-3 fatty acids on performance, like improved endurance, reduced soreness, and enhanced recovery—at least for amateur athletes. However, they do note that clear recommendations about these supplements are hard to come by and put into practice.
“For athletes, when you engage in really intense exercise, whether it’s aerobic cardiovascular exercise or weightlifting exercise, if it’s really intense exercise, you’re going to cause muscle damage as a result of that exercise,” says Garay, who mentions this is why some researchers are focused on omega-3s to help you recover from this effect of exercise. Most researchers note, however, that athletes may need higher amounts of omega-3s than the average population to reap these benefits.
Are there any downfalls of fish oil supplements?
Supplements aren’t regulated by the FDA in the same way as conventional food and drugs products. Meaning, the FDA doesn’t have authority to approve dietary supplements before they hit the market with the exception for anything that contains new dietary ingredients which have yet to be approved by the administration.
“A general note about all supplements is that they do not have to be proven safe or effective before being sold. With fish oil supplements specifically, there are large variations in quality,” says Garay. Because these products are so loosely regulated, she adds, there can be risk for contamination and concerns for high mercury levels.
To address this issue, look for products that have been tested by a third party like USP or NSF, two leaders in the industry. “Somewhere on the label they'll have the credential from the third party testing company,” Garay says.
Also, consider the source of the fish oil, Garay says. Fish oil supplements made from krill may be purer, and therefore, have lower levels of mercury because they likely don’t consume any other animals. Also, non-fish marine sources like algae, she says, can be good options.
Another important takeaway is there’s still no way to know if you’re getting the exact dosages promised on the labels. In some instances, you might be getting less.
In fact, researchers of one study published in the Journal of Food Composition and Analysis tested 48 fish oil supplements on the U.S. market for label compliance and oxidative quality and found the amounts were off from the label. The majority of the products tested in the study were of good quality, but 48 percent of products contained less EPA and DHA than what was claimed on the label, while still within the legal range of what’s considered to be safe.
In terms of performance, Chris McGlory, Ph.D, an exercise and nutrition researcher and assistant professor at Queen’s University’s School of Kinesiology and Health Studies tells Bicycling there aren’t many studies on omega-3s that include cyclists and taking supplements likely won’t impact training for healthy young individuals.
One study spearheaded by McGlory found omega-3 supplementation slowed the decline in skeletal muscle volume for participants who didn’t move much. “There is potential for omega-3 fatty acids to protect against skeletal muscle loss during immobilization in young women, but more work needs to be done,” he says.
To the contrary, he says, “the story is slightly different in older people, particularly in women. Omega-3 supplementation may help improve gains in skeletal muscle strength during resistance exercise training.” In other words, these supplements may benefit some populations, but not others.
Another caveat to consider when it comes to taking fish oil supplements: Researchers of a review and meta-analysis published in the American Heart Association’s journal Circulation found an association between omega-3 supplementation and atrial fibrillation (irregular and rapid heart rhythm) when participants consumed more than 1 gram per day of omega-3 supplements.
Similarly, a longitudinal study published in BMJ Medicine associated regular use of fish oil supplements with an increased risk of atrial fibrillation in people with a healthy cardiovascular profile that used fish oil supplementation as a preventative measure. However, for patients with atrial fibrillation the study found regular use of fish oil supplements as a secondary preventative measure had a protective effect or no effect on the condition progressing to major adverse cardiovascular events such as heart failure, stroke, heart attack, or death.
What's the best way to add more omega-3s and other nutrients found in fish oil supplements to your diet?
Eating whole fish and seafood will offer the best source of EPA and DHA, Garay says. “There are many benefits to eating fish or other marine sources beyond the presence of omega-3s. Fish are a good source of protein and iron,” she explains. “Canned fish are often canned with bones, so they can actually provide some calcium, if you’re eating the bones of the fish as well.” You won’t get those extra advantages from supplements.
Ultimately, fish oil supplements aren’t meant to be a miracle worker, says Garay. Meaning you need to do more than just take a supplement each day to reap the anti-inflammatory benefits of it.
“If you’re doing things that are separately promoting inflammation in the body—if you’re sedentary a lot, and not being physically active, if you’re consuming a lot of processed foods, and high-fat, high-sugar, high-calorie foods, if you smoke—you can’t just completely offset that by taking the fish oil supplements,” she says.
Also, you shouldn’t swap out eating fish a couple times a week for a fish oil pill. According to the recent Dietary Guidelines for Americans, people who consume about 2,200 calories each day should aim to eat approximately 9 ounces of seafood each week.
Start by eating 2 to 3 ounces of fish or other seafood about two or three times a week, McGlory suggests. (That’s also the recommendation by the American Heart Association.) Fatty fish like sardines and anchovies are the best sources of omega-3’s, says Garay. But salmon, herring, flounder, and mackerel are good sources as well.
Consult with your doctor or a registered dietitian to find out exactly how much omega-3s you’re consuming each week and where your diet is lacking—especially before taking a supplement. You can also ask your doctor for a blood test to scan for omega-3s.
In the end, if you do decide to add a fish oil supplement to your diet, McGlory suggests finding a pill that offers about 250 mg of EPA and DHA per day, which is in line with what the FDA regards as safe. The FDA also recommends consuming no more than 5 grams of EPA and DHA, combined from dietary supplements each day. So if you already eat fish, then you probably don’t need the supplement.
Monique LeBrun joined the editorial staff in October 2021 as the associate health and fitness editor. She has a master’s degree in journalism and has previously worked for ABC news and Scholastic. She is an avid runner who loves spending time outside.
Dr. Namrita Brooke is a full-time endurance sport coach and sport nutritionist advising active individuals and amateurs to professional athletes. She is also an adjunct professor in the Department of Movement Sciences and Health at University of West Florida. Professionally, she also serves on the Board of Editors of the Sports Nutrition Care Manual and remains involved in nutrition and exercise-related research, student mentorship, and coach development. Namrita's personal athletic experience ranges from ultra-endurance mountain biking to off-road triathlon, cross-country mountain bike racing, gravel cycling, duathlon, cyclocross, running, and trail running. Her research background includes hydration and sports drink research, and the interaction of nutrition, physical activity, and the brain.
