free radical

noun

Definition of free radical

: an especially reactive atom or group of atoms that has one or more unpaired electrons especially : one that is produced in the body by natural biological processes or introduced from an outside source (such as tobacco smoke, toxins, or pollutants) and that can damage cells, proteins, and DNA by altering their chemical structure

Examples of free radical in a Sentence

Recent Examples on the Web The honey adds a boost of antioxidants to the gentle formula, which lessens free radical damage on the skin, while the pumpkin gives natural moisturization benefits. Braelyn Wood, Health.com, "Ali Wong Loves This Andalou Naturals Mask for Baby-Soft Skin," 10 Dec. 2019 Spinach is rich in lutein, potassium, fiber and brain-boosting folate, and just one cup of raw leaves contains 15% of your daily intake of vitamin E, an important antioxidant for fighting off the damaging molecules known as free radicals. Sandee Lamotte, CNN, "Top 34 bestselling 'fruit' drinks for kids deemed unhealthy," 16 Oct. 2019 The Dsup protein protects DNA under conditions that create caustic free radical chemicals. Susanne Bard, Scientific American, "Tardigrade Protein Protects DNA from Chemical Attack," 16 Oct. 2019 The reactions a cell uses to produce energy also generate side products called free radicals, which can trigger Maillard-like reactions and produce polymers similar to those in the fossil protein residues. Gretchen Vogel, Science | AAAS, "Warm-blooded velociraptors? Fossilized proteins unravel dinosaur mysteries," 8 Oct. 2019 In a nutshell, oxidative stress occurs when there is an imbalance between the production of cell-damaging free radicals and the body's ability to counter their harmful effects, which include premature aging and disease risk. Cynthia Sass, Mph, Health.com, "Cauliflower Benefits: 7 Ways This Vegetable Helps Your Health," 23 Oct. 2019 Antioxidants are substances that neutralize free radicals — unstable oxygen molecules that break down skin cells and cause wrinkles. Mayo Clinic News Network, chicagotribune.com, "Home remedies: Weathering those wrinkles," 25 Oct. 2019 These compounds are known to help keep inflammation low by neutralizing free radicals—which can cause cell damage that in turn can lead to chronic disease such as heart disease and cancer. Julie Upton, Health.com, "Pear Nutrition: 5 Ways This Fruit Can Boost Your Health," 24 Oct. 2019 And we are told that antioxidants in superfoods and beauty products will mop up free radicals, protecting us from their aging effects and keeping us young and disease-free. William Mair, Twin Cities, "William Mair: Five myths about aging," 24 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'free radical.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of free radical

1870, in the meaning defined above

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Time Traveler for free radical

Time Traveler

The first known use of free radical was in 1870

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Statistics for free radical

Last Updated

30 Dec 2019

Cite this Entry

“Free radical.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/free%20radical. Accessed 18 January 2020.

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More Definitions for free radical

free radical

noun

Medical Definition of free radical

: an especially reactive atom or group of atoms that has one or more unpaired electrons especially : one that is produced in the body by natural biological processes or introduced from outside (as in tobacco smoke, toxins, or pollutants) and that can damage cells, proteins, and DNA by altering their chemical structure

More from Merriam-Webster on free radical

Britannica.com: Encyclopedia article about free radical

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