What’s the Deal with Fish Oil?

Kamal Patel
by Kamal Patel
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What’s the Deal with Fish Oil?

Among the rows and rows of vitamins and supplements on store shelves these days, fish oil stands out. Experts speak highly of it, and many Americans are already popping a gel cap daily, but what exactly are you swallowing? What does “omega-3” mean? Do you need to supplement with “omega-6” as well? And, perhaps most importantly, does fish oil actually deserve its health halo?

To understand fish oil, you need to understand oils and fats

Fat comes in solid and liquid forms. Most animal fats are solid, such as butter or beef fat, and most plant fats are liquid, such as olive oil. One of the most notable exceptions is fish oil, which is liquid at room temperature.

Fish have a different fat profile than warm-blooded land animals. Unlike beef fat, fish fat is liquid because fish are cold-blooded and often swim in cold water. If their fat stores were mostly saturated, the fat would be solid at those cool temperatures, and solid fat would lead to one stiff fish—not exactly conducive to swimming.

Seafood is unique in its high omega-3 content, especially the fats known as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are very important for human health, namely for optimal immune and nervous system function. Since the human body cannot produce them, omega-3 and omega-6 fats must come from the diet.

Omega-3 vs. omega-6

Wonder why you see lots of omega-3 supplements, but rarely come across omega-6 supplements? It’s because we tend to get way too much omega-6 in our diets. The omega-6 to omega-3 ratio of human diets was somewhere between 1:1 and 4:1 as humans evolved, meaning early humans ate almost the same amount of omega-6 fats as omega-3 fats. The ratio remained that way until a few decades ago. With the advent of inexpensive corn and soybean oil, which both happen to be rich in omega-6, Americans now consume vastly more omega-6 than omega-3 than their earlier ancestors. Today, ratios of 15:1 to 20:1 are more common.

There are several different types of omega-6 fats, and some are can actually be healthy. Omega-6 rich olive oil, for example, has very different health effects than unhealthy corn oil, which is also rich in omega-6. Corn oil has five times as much omega-6 as olive oil, and offers no nutritional benefits, while olive oil has been linked to a decrease in chronic disease.

Should you supplement with fish oil?

Fish oil supplements, in pill or liquid form, are not recommended for everyone. If you eat fatty fish, such as wild salmon, arctic char, and atlantic mackerel, on a regular basis, you’re likely getting plenty of omega-3 in your diet—in a much tastier way than those pills. Fish oil is not something that you need daily, and it’s also possible that you’re getting some omega-3 by eating grass-fed meats and free-range eggs. Plus, those who avoid vegetable oils high in the unhealthy types of omega-6, like corn and soybean oil, will have better omega-3 to omega-6 ratios and may not need fish oil supplements.

If thinking about taking a supplement, consider the following benefits: fish oil has been shown in studies to reduce heart disease predictors, including triglycerides and blood pressure. It also shows promise for helping to alleviate depression, though more research is needed to confirm this effect. Still, eating several servings of foods high in omega-3 and including healthy fats from olive oil, pastured meats, and coconut oil may make supplementation unnecessary.

While potentially beneficial, fish oil supplements may also come with a few side effects. Though there isn’t much evidence to suggest fish oil is directly harmful, it’s not a good idea to consume a lot of it daily. For example, taking more than a few teaspoons of fish oil at a time may lead to stomach upset. More importantly, large doses over time could increase the risk of hemorrhage. And those with blood disorders, including conditions that prevent blood coagulation, should talk to their doctor before supplementing fish oil. (It’s a good idea to discuss any and all supplements you take—or plan to take—with your physician.)

To supplement omega-3 effectively, stay away from combination supplements that contain omega-3 in addition to omega-6, and in some cases even omega-9—you just don’t need those extra 6s and 9s. For those trying to avoid animal-based supplements, flaxseed oil is an option—it’s a major plant source of omega-3. However, only about 10% of the omega-3 found in flaxseed is converted in the body to the EPA and DHA that we need. Marine-derived oils are usually a better choice for supplementing omega-3 due to their preformed EPA and DHA.

Fish oil oxidizes easily, making storage tricky. Keep your bottle in the refrigerator to slow oxidation, and avoid buying large bottles of capsules or liquids. While the price per capsule may be hard to resist, buying in bulk could put lead to accidental oxidation—smaller bottles are open for, and used up, in a shorter period of time.

Bottom line

Fish oil is not a must-take supplement. Think of it as a springboard to being aware of the fats in your diet. Whether you take fish oil or eat fatty fish or pastured meats, it’s important to get enough omega-3 fats, since your body can’t produce them by itself. Equally important is watching the types of oils you eat.

When cooking at home, opt for olive oil instead of standard vegetable oil (which are often a bulk mix of corn and soybean oils), and ask your waiter about the ingredients in your salad dressing when dining out. Paying attention to the types of fat you eat can go a long way toward preventing disease and maintaining health. Use MyFitnessPal to keep track of the types of fats you eat, and your body will thank you for the effort.

Do you take fish oil supplements? Share your thoughts in the comments below.


About the Author

Kamal Patel
Kamal Patel

Kamal Patel is the director of Examine.com. He has an MBA and an MPH (Master of Public Health) from Johns Hopkins University, and was pursuing a PhD in nutrition when he opted to go on hiatus and join Examine.com. He is dedicated to making scientific research in nutrition and supplementation accessible to everyone. Both Examine.com and Kamal are on Facebook.

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