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

Fish Various types of fish contain protein, vitamin D, omega-3 fatty acids, and other essential nutrients after age 60. —Brittany Lubeck, Verywell Health, 8 Sep. 2025

In a new study, women with Alzheimer’s had lower levels of omega-3s, and there was no difference in men. —Brian Mastroianni, Health, 5 Sep. 2025

Eating healthy, oily fish, which are packed with omega-3 fatty acids, is encouraged, while eggs, dairy and poultry are eaten in much smaller portions than in the traditional Western diet. —Sandee Lamotte, CNN Money, 25 Aug. 2025

These can include turmeric, omega-3 fatty acids, live probiotics, herbals like oregano and minerals like calcium, iron and zinc. —Bestreviews, Mercury News, 21 Aug. 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