antioxidant

American  

[an-tee-ok-si-duhnt, an-tahy-] / ˌæn tiˈɒk sɪ dənt, ˌæn taɪ- /

noun

• antioxidants
  plural

1. Chemistry. any substance that inhibits oxidation, as a substance that inhibits oxidative deterioration of gasoline, rubbers, plastics, soaps, etc.

2. Biochemistry. an enzyme or other organic substance, as vitamin E or beta carotene, that is capable of counteracting the damaging effects of oxidation in animal tissues.

---

adjective

1. Chemistry. of or relating to an antioxidant.

antioxidant British  

/ ˌæntɪˈɒksɪdənt /

noun

1. any substance that retards deterioration by oxidation, esp of fats, oils, foods, petroleum products, or rubber

2. biology a substance, such as vitamin C, vitamin E, or beta carotene, that counteracts the damaging effects of oxidation in a living organism

---

antioxidant Scientific  

/ ăn′tē-ŏk′sĭ-dənt,ăn′tī- /

1. A chemical compound or substance that inhibits oxidation. Certain vitamins, such as vitamin E, are antioxidants and may protect body cells from damage caused by the oxidative effects of free radicals.

---

Other Word Forms

Noun Inflected Forms

• antioxidants
  plural

Etymology

Origin of antioxidant

First recorded in 1925–30; anti- + oxidant ( oxid(ize) + -ant )

Explanation

An antioxidant is a substance that helps prevent damage caused by certain chemical reactions in our bodies. Fruits, vegetables, and beans are full of antioxidants. Vitamins C and E are familiar antioxidants found in foods like spinach, strawberries, kiwifruit, and lima beans. These substances work in two main ways. They sometimes prevent chemical oxygen reactions that produce damaging, unstable free radicals. They can also bind with the free radicals to make them stable and keep them from causing damage. Antioxidants don't just protect our bodies; they are also used to keep food fresh — a squeeze of lemon juice (Vitamin C) on a sliced apple helps prevent oxidation that turns the fruit brown.

Example Sentences

See Examples For:

antioxidant antioxidants

Exercise also boosts antioxidant enzymes in the body, which protect cells from damage.

From The Wall Street Journal ● Jul. 23, 2026

Augustine Lee, a pulmonologist with the Mayo Clinic’s Jacksonville, Fla., campus, says a lifestyle and diet that promote antioxidant buildup is associated with less heart disease and cancer.

From The Wall Street Journal ● Jul. 23, 2026

Among all the varieties tested, kombuchas prepared from green tea and oolong tea demonstrated the strongest antioxidant activity and the greatest capacity to neutralize free radicals.

From Science Daily ● Jun. 23, 2026

And evidence reviews have found that some high-dose antioxidant supplements, particularly beta-carotene and vitamin E, may increase mortality risk in some populations.

From Science Daily ● Jun. 6, 2026

“Just some antioxidant recipes. Ready for BiPAP and America’s Next Top Model?” she asked.

From "The Fault in Our Stars" by John Green

Foods filled with antioxidants include dark green vegetables, blueberries, nuts, green tea or fish.

From The Wall Street Journal ● Jul. 23, 2026

Instead, add a handful of berries, kiwis, or other fruits rich in fiber and antioxidants.

From MarketWatch ● Jun. 21, 2026

These antioxidants, found in certain foods, can support heart health, circulation and blood vessel elasticity by reducing inflammation, it says.

From BBC ● Jun. 8, 2026

Whether served at a summer barbecue, blended into smoothies, or added to salads, watermelon offers a simple way to increase fruit intake while adding vitamins, antioxidants, and hydration to your diet.

From Science Daily ● May 17, 2026

When things had felt so out of control, all Grace could do was make sure she was healthy, so she had learned about antioxidants and omega-3s and folic acid.

From "Far from the Tree" by Robin Benway