Your grandmother may have sworn by her fish oil tablets, the giant ones with the fishy burps. Maybe you figure you don't need them: your heart's in good shape and you work out. But omega-3s aren't only about heart health. They're structural fats in your brain and eyes, they help regulate your body's inflammatory response, and they matter for a baby's development. So what's with the alphabet: ALA, EPA, DHA? Let's break it down.
What makes omega-3 an essential nutrient?
An essential nutrient is one your body needs but can't make, so it has to come from food or supplements. For omega-3s, the essential one is ALA (alpha-linolenic acid). The adequate intake listed by the NIH Office of Dietary Supplements is 1.6 g of ALA a day for men and 1.1 g for women.
The good news is that ALA is easy to find in plant foods. Flaxseed, chia seeds, hemp seeds and walnuts are at the top of the list, so a tablespoon of ground flax in your morning smoothie is a great habit.
What's the difference between EPA and DHA?
EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are the long-chain omega-3s. They're found mainly in fatty fish and in algae, and fish actually get theirs by eating algae.
- DHA is a major structural fat in the brain and the retina, and it's present in breast milk (NIH Office of Dietary Supplements).
- EPA is a building block for signaling molecules that help regulate the body's inflammatory response, and both EPA and DHA are part of cell membranes throughout the body (ODS).
There's no official U.S. intake target for EPA and DHA, but because your body makes so little of them from ALA, getting them preformed from food or a supplement is the reliable route.
How well does your body convert ALA into EPA and DHA?
Not very well. Turning ALA into EPA takes a chain of enzyme steps, and getting from EPA to DHA takes several more. Studies using labeled ALA estimate that adults convert about 6% of ALA to EPA and 3.8% to DHA. Women convert somewhat more than men, which researchers think may be an effect of estrogen, but in everyone the step to DHA is very limited.
Diet makes it worse. Omega-6 fats, found in many vegetable oils and processed foods, compete for the same enzymes. On a diet rich in omega-6, conversion drops by another 40 to 50%. That matters because Western diets are estimated to carry roughly 15 to 17 times more omega-6 than omega-3, compared with a ratio close to 1:1 in the diets humans evolved on.
Why does DHA matter for your brain?
The human brain is nearly 60% fat, and DHA is the main omega-3 in it. Dietary DHA is needed for the normal development of the retina and visual cortex, and researchers continue to study its role in adult brain health. Given how little DHA the body makes from ALA, relying on flax and chia alone is a long road to get there.
So where should you get your omega-3s?
Keep eating ALA-rich plant foods: they're good for you. For EPA and DHA, you have two options. Oily fish such as salmon and sardines, or algae, the original source. If you're vegan or want to avoid ocean contaminants, algae is the way to go, and DHA from algal oil is absorbed as well as DHA from cooked salmon.
That's why we make Head & Heart from algae: 500 mg of DHA per serving, vegan, and third-party tested for heavy metals and contaminants. For more on plant sources, read how to get vegan omega-3, and if you're expecting, what to know about omega-3 during pregnancy.
