Are Plant-Based Omega-3s as Good as Fish Oil?

By Sarah McColl

March 1, 2021

Omega-3 fatty acids are critical to good health. They help to prevent heart disease and stroke, cancer, arthritis, and memory loss. Recent studies also suggest they may alleviate depression and reduce post-traumatic stress disorder. Yet, unlike other fats, we’re incapable of making our own. We have to get omega-3s from fish or from certain plant-based foods, such as flax or chia seeds, walnuts, or leafy vegetables such as spinach.

So what’s the best way to incorporate omega-3s into your daily diet? And are all sources created equal? The science is conclusive.

Marine-Based Omega-3s vs. Plant-Based Omega-3s

When you eat marine-based sources of omega-3s you’re getting long-chain omega-3 fatty acids, specifically DHA and EPA. When you eat a handful of walnuts or spoonful of flax seeds you’re getting ALA, a shorter-chain omega-3 fatty acid. Bottom line? DHA and EPA from fish have more significant health benefits than ALA from plant-based foods.

Now, there’s an enzyme that can convert ALA into long-chain omega-3s, but that conversion depends on a host of factors like sex, age, and what other kinds of fats you consume. The conversion rate is typically less than 1%; some studies have found it’s as low as 0.1 to 0.5 percent. In short, no human studies have shown that vegetarian omega-3 sources lead to truly beneficial levels of EPA and DHA inside the body’s cells and tissues.

“If I’m advising a patient on the most reliable forms of EPA and DHA to help with medical conditions such as high triglycerides, arthritis, allergies, depression or autoimmune conditions, I usually recommend a reliable, clean fish oil source,” says Rachel Carlton Abrams, MD, author of Bodywise: Discovering Your Body’s Intelligence for Lifelong Health and Healing.

For her vegetarian patients who want a DHA supplement, algae-sourced DHA is available, she said. But it is much harder to extract and much more expensive to manufacture. “For most of us, a high-quality fish oil supplement is the way to get a reliable boost in our EPA and DHA levels.”