New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Antioxidant

An antioxidant is a chemical that reduces the rate of particular oxidation reactions in a specific context, where oxidation reactions are chemical reactions that involve the transfer of electrons from a substance to an oxidizing agent, this generally results in different chemicals to the original ones.

Antioxidants are particularly important in the context of organic chemistry and biology. All living organisms maintain a reducing environment inside their cells, all cells contain complex systems of antioxidants to prevent chemical damage to the cells' components by oxidation. These antioxidants include glutathione and ascorbic acid and are substrates for enzymes such as peroxidases and oxidoreductases.

Antioxidants are widely used as ingredients in dietary supplements used for health purposes such as preventing cancer and heart disease. Studies have suggested antioxidant supplements has benefits for health, but several large clinical trials did not demonstrate a definite benefit for the formulations tested, and excess supplementation may even be harmful.

Dietary supplementation has few specific antioxidants compared to a broad diet rich in phytonutrients, which will yield thousands of different polyphenol antioxidants available for metabolism.

Related Stories
 


Health & Medicine News

April 1, 2026

Millions of people start work before sunrise—but their brains aren’t ready for it. A new clinical trial has found that the wake-promoting drug solriamfetol can significantly boost alertness in early-morning shift workers struggling with shift ...
Cells aren’t as passive as scientists once thought—they actively create internal currents to move proteins quickly and efficiently. These “cellular winds” push materials to the front of the ...
A surprising breakthrough suggests that a drug best known as Viagra could help treat a devastating childhood disease. Researchers found that sildenafil significantly improved symptoms in patients ...
DNA robots are emerging as tiny programmable machines that could one day deliver drugs, hunt viruses, and build molecular-scale devices. By borrowing ideas from traditional robotics and combining them with DNA folding techniques, scientists are ...
Salt substitutes offer a simple, low-cost way to reduce sodium intake and improve blood pressure, yet very few Americans actually use them—even among those who need them most. A large national analysis spanning nearly two decades found that usage ...
Scientists have uncovered a surprising secret about our DNA: it’s not a static blueprint, but a constantly shifting, folding structure that helps control how genes turn on and off. Researchers at the Salk Institute found that different parts of ...
A breakthrough urine test could dramatically speed up how doctors treat urinary tract infections, identifying the right antibiotic in under six hours instead of waiting days. By testing directly from urine—skipping the usual lab culturing ...
A dramatic surge in kratom-related poison center calls is raising alarm among health experts, as new data shows cases have jumped more than 1,200% over the past decade. Alongside the spike, hospitalizations and deaths linked to the widely available ...
A new study suggests that simplifying your diet by eating the same meals and keeping your calorie intake consistent could help you lose more weight. Researchers found that people who followed predictable eating routines during a 12-week program lost ...
Deep sleep does far more than rest the body — it activates a powerful brain-driven system that controls growth hormone, fueling muscle and bone strength, metabolism, and even mental performance. ...
A major analysis of nearly 10,000 patients shows that simple, non-drug treatments like knee braces, hydrotherapy, and exercise can significantly ease knee osteoarthritis symptoms. These approaches not only reduce pain and improve mobility, but also ...
A large U.S. study reveals that more than a quarter of people with hard-to-treat high blood pressure may have an overlooked hormone problem. Elevated cortisol—often linked to stress—was found in 27% of these patients, far higher than expected. ...

Latest Headlines

updated 12:56 pm ET