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

Every plate contains high-quality protein to support muscle repair and recovery, carbohydrates to replenish energy stores, as well as omega-3 fatty acids, vitamin D, calcium, iron and magnesium. — Jordan Campbell, New York Times, 29 June 2026

When part of a person’s regular diet, omega-3 fatty acids certainly play a vital role in maintaining health over the long term. — Drew Pittock, USA Today, 29 June 2026

To get enough omega-3s, adults should aim to eat fatty fish twice per week and 1-2 g of ALA daily. — Matt Fuchs, Time, 26 June 2026

All had extremely low omega-3 levels and at least one risk factor for dementia, such as obesity, sedentary lifestyle, high blood pressure, or cholesterol. — Michele Laufik, Martha Stewart, 26 June 2026

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