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

Tuna is an excellent source of omega-3 fatty acids, which may help improve overall cardiovascular health.9 17. —Lauren Manaker Ms, Health, 19 June 2025

Dosage Higher doses of fish oil introduce more omega-3s into your system, which may take longer to clear than smaller amounts. —Lindsay Curtis, Verywell Health, 12 June 2025

Read on for some common examples and their approximate omega-3 content per typical serving size. —Caroline Tien, SELF, 12 June 2025

His research has focused on omega-3 fatty acids, including the neurocognitive development of children whose mothers consumed seafood during pregnancy. —Erika Edwards, NBC news, 11 June 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