omega-3

adjective

ome·​ga-3 ō-ˈmā-gə-ˈthrē 

-ˈmē-,

-ˈme- 

: being or composed of polyunsaturated fatty acids that have the final double bond in the hydrocarbon chain between the third and fourth carbon atoms from the end of the molecule opposite that of the carboxyl group and that are found especially in fish, fish oils, green leafy vegetables, and some nuts and vegetable oils compare omega-6

omega-3 noun

Examples of omega-3 in a Sentence

Recent Examples on the Web

This includes fresh fruit and vegetables, lean proteins, omega-3 fatty acids (found in fish, walnuts, and Brazil nuts), and complex carbohydrates (kiwis, tangerines, apples, and others). —Mark Gurarie, Health, 22 Sep. 2025

While omega-3 fatty acids in fish oil can lower triglycerides and may support heart health, high doses have been linked to a higher risk of atrial fibrillation (AFib). —Stephanie Brown, Verywell Health, 19 Sep. 2025

Diets rich in fruits, vegetables, whole grains, lean proteins and omega-3 fatty acids support brain health, says Mander. —Daryl Austin, USA Today, 19 Sep. 2025

But common seed oils like sunflower, safflower, soybean, and canola oil are rich in omega-3 and polyunsaturated fats, including essential fatty acids our bodies can’t produce on their own, and that play an important role in our brain and overall health. —Amy Brightfield, Better Homes & Gardens, 17 Sep. 2025

Word History

First Known Use

1967, in the meaning defined above

Medical Definition

omega-3

adjective

ome·​ga-3 -ˈthrē 

variants also Omega-3

: being or composed of polyunsaturated fats that have the first double bond in the hydrocarbon chain occurring between the third and fourth carbon atoms from the end of the molecule most distant from the carboxylic acid group and that are found especially in fish, fish oils, green leafy vegetables, and some nuts and seeds

The two main omega-3 fatty acids in fish oil … appear to reduce the risk of dying from sudden cardiac arrest by about 30 percent.

—Nutrition Action Health Letter

compare omega-6

omega-3 noun

also Omega-3

Some plants, such as linseed, naturally produce an omega-3 called alpha-linolenic acid (ALA), and one way to increase the amount of omega-3 in our diet is to eat these plants …

—Andy Coghlan, New Scientist