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

Some research in animals also suggests that omega-3 fatty acids—found abundantly in fish—could enhance egg quality, while research in people using assisted reproductive tech (ART) like IVF points to a link between consumption of these fats and higher birth rates (though the reason why isn’t clear). —Erica Sloan, SELF, 18 Apr. 2025

Nuts contain healthy fats that can support heart health and reduce inflammation, are rich in fiber and protein to keep people satiated, and are high in omega-3s to support brain health (especially walnuts). —Alexa Mikhail, Fortune, 15 Apr. 2025

Breaking down 6 of the biggest claims Dr. Sun recommends choosing fish that are low in mercury a heavy metal that can be particularly dangerous for children and pregnant women) and high in omega-3 fatty acids. —The New York Times, San Diego Union-Tribune, 15 Apr. 2025

Pet Honesty chews are vet-recommended and made with natural ingredients like mushrooms, omega-3s from salmon oils and turmeric. —Christopher Murray, FOXNews.com, 12 Apr. 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