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

May 11, 2026

An ancient Chinese exercise routine may be just as powerful as a daily brisk walk for lowering blood pressure — without equipment, gyms, or intense workouts. In a major clinical trial, adults with stage 1 hypertension who practiced baduanjin, a ...
Researchers say fructose is not just “empty calories” — it may actively push the body toward fat storage and metabolic disease. A new review found that fructose affects the body differently ...
A new international analysis suggests there may be a surprisingly simple secret to keeping weight off after dieting: walking about 8,500 steps a day. Researchers found that people who boosted their daily steps to around that level during a ...
A major new analysis suggests semaglutide (Ozempic, Wegovy) works remarkably well in adults over 65, helping many lose substantial amounts of weight while improving heart and metabolic health. Participants taking the drug lost over 15% of their body ...
Ultra-processed foods may be doing far more damage than many people realize. A major new European cardiology report warns that people who eat the most ultra-processed foods face significantly higher ...
Scientists at the University of Rochester pulled off a remarkable experiment: they transferred a longevity-related gene from the famously long-lived naked mole rat into mice, and the mice ended up healthier and lived longer. The special gene boosts ...
Scientists have uncovered a hidden “stop-scratching” signal in the nervous system that tells your brain when enough scratching is enough. The discovery centers on a molecule called TRPV4, which acts like part of an internal braking system for ...
Rebooting the gut microbiome with bacteria from youth may help stop aging-related liver damage and even prevent liver cancer, according to new research in mice. Older mice that received their own preserved youthful microbiome showed less ...
Researchers have developed a stem cell-based model of the human intestine that may transform how new IBD treatments are discovered. After testing thousands of compounds, they identified glycyrrhizin — a natural substance found in black licorice ...
A new study shows that listening to your own favorite workout music can dramatically boost endurance. Cyclists exercising with self-selected songs lasted nearly 20% longer than when riding in silence, yet they didn’t feel more exhausted at the ...
Scientists studying axolotls, zebrafish, and mice have uncovered a shared set of genes that may one day help humans regrow lost limbs. By identifying powerful “SP genes” involved in regeneration, ...
Scientists have uncovered a surprising secret hidden inside fat cells that could reshape how we think about obesity and metabolic disease. A protein called HSL, long believed to simply release stored fat when the body needs energy, turns out to have ...

Latest Headlines

updated 12:56 pm ET