What Are Omega-3s, Actually? Here's The Lowdown On These Healthy Fats

Even during the days of low-fat everything, one specific type of fat maintained its "good for you" status: omega-3s. And though nutrition science and health trends have since brought all sorts of dietary fats back into the mainstream's good graces, omega-3s still deserve some extra attention.

The bottom line is: you need your fair share of these high-profile fats in order to feel your best.*

Though they're most famous for heart health, omega-3s fuel a slurry of important processes in the body, supporting everything from your brain to your eyes.*

If that's the extent of your knowledge about omega-3s, don't sweat it; you've come to the right place.

"Omega-3s [EPA and DHA] are a family of fatty acids that are primarily found in higher-fat fish," says William Harris, Ph.D., FASN, FAHA, co-creator of the omega-3 index1 (a blood test that measures the amount of EPA and DHA in your red blood cell membranes). 

Harris goes on to say this about EPA and DHA: "These are fatty acids that our bodies are very inefficient at making and so are best supplied directly through the diet." (For this reason, they're known as "essential" [ALA] or "conditionally essential" [EPA and DHA] fatty acids by many renowned lipid researchers, including Harris.)

Within this family of omega-3s, there are three specific fats you've probably heard of before—and that are praised far and wide for their various health benefits: EPA, DHA, and ALA.*

A shorter-chain PUFA, ALA is the parent fatty acid of the omega-3s and found in plants. It can be metabolized into EPA and DHA in the liver3, but only at an inefficient and highly variable rate (that differs between women and men and as we age) of 5 to 20 percent4.

Because of this, consuming foods high in ALA is not an effective way to get the EPA and DHA we need, Harris says. In fact, he believes it's nearly impossible to achieve optimal EPA and DHA levels by consuming ALA alone.* And that belief is rooted in published clinical evidence5.

EPA is a long-chain PUFA produced by water plants (like algae)6, but we typically get it from fish (which consume said algae).

Similarly, DHA is also a long-chain PUFA found in algae and fish. This particular omega-3 is found in high concentrations in the retina and brain8 (i.e., the central nervous system), making it essential for the development of our brain and eyes, as well as vision and cognitive function throughout life.*

DHA, in particular, helps to regenerate rhodopsin11, a visual pigment involved in converting the light that hits your retina into the visual images you see.* Because of this, it's crucial for retina development and function9.*

You've already heard time and time again that omega-3s are heart healthy.* Research shows that higher concentrations of omega-3s are associated with optimal cardiovascular function13, including healthy circulation and blood pressure regulation.*

Omega-3s are important for pathways that contribute to synaptic plasticity and memory14, both of which support learning.* Diets high in these fats are also associated with healthy cognitive function15.*

They may also support various aspects of mood and mental well-being.* Some research, for example, suggests that omega-3s support the body's ability to respond to and cope with feelings of stress16.*

Fish are our most obvious source of omega-3s and provide the body with the long-chain omega-3 fatty acids EPA and DHA.*

Not sure which fish to turn to? Functional physician Mark Hyman, M.D., recommends using the acronym SMASH (which stands for "salmon, mackerel, anchovies, sardines, herring") when stocking your fridge with fresh filets and pantry with canned and tinned fish.

That doesn't mean that people who don't consume animal products are out of luck, though. Since sea plants like algae are the original source of omega-3s for fish, you can get EPA and DHA by consuming them as well.

In fact, many algal oils available these days are great sources of DHA20, in particular.

You can get ALA, meanwhile, from a variety of plant foods, including walnuts, flaxseeds, flaxseed oil, and edamame21.

Research has long shown that Americans don't consume much fish. "Typical intakes of EPA and DHA in the U.S. (a low fish-eating country) are about 100 to 150 milligrams per day, on average," Harris explains. "In countries like Japan or Korea, where fish is eaten nearly every day, though, intakes are between 750 and 1,000 milligrams per day."

As a result, "the typical American has an omega-3 index of 4 to 6%, whereas the typical Japanese and Korean person falls between 8 and 12%," he says. (A level equal to or greater than 8% is considered optimal.)*

Achieving an optimal omega-3 index, Harris says, would require most Americans to consume about 1,000 to 1,500 milligrams of EPA+DHA per day—a far cry from the average current intakes in this country.

Indeed, mbg's vice president of scientific affairs Ashley Jordan Ferira, Ph.D., RDN, shares that, "Nationally representative data proves how low our fish intake truly is, with more than 90% of Americans22 failing to consume the recommended (baseline starting point) two servings of fish per week, which equates to roughly 500 mg of EPA plus DHA daily. On average, as a country, we're actually eating less than 90 mg of these marine omega-3s23 per day."

She goes on to say, "Mind you, we actually need a 1,000 milligram-plus to optimize heart and whole-body health throughout life. That superior amount of omega-3s is the equivalent of eating a fish a day."*

Fun fact: Omega-3s aren't the only omegas out there. Omega-6 fats, which are found in many plant foods (most notably vegetable oils, with canola and soybean oils being some of the worst offenders), are another component to consider when evaluating your omega-3 intake.

Here's the deal: While omega-6s play a role in brain development and function (among other things), they also promote inflammatory pathways in the body.

This isn't a bad thing, as long as we maintain the proper balance of omega-6s and omega-3s. That's where things get a little hairy.

While research suggests the optimal balance is a 2:117 ratio of omega-6s to omega-3s, the average American diet has a ratio closer to 10:1 or even as high as 20:117, highlighting that many Americans could benefit from cutting back on omega-6s and seriously boosting their consumption of omega-3s.*

Given all of the good things omega-3s do throughout the body, it's no shock that falling short on them isn't exactly ideal for our health.

Feel a little more fluent in the language of omega-3s? These healthy fats are important for maintaining a number of areas of health, including everything from your cardiovascular system to your mood.*