Antioxidant
hideAn antioxidant is a molecule capable of slowing or preventing the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals, which start chain reactions that damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibit other oxidation reactions by being oxidized themselves. As a result, antioxidants are often reducing agents such as thiols, ascorbic acid or polyphenols.
Although oxidation reactions are crucial for life, they can also be damaging; hence, plants and animals maintain complex systems of multiple types of antioxidants, such as glutathione, vitamin C, and vitamin E as well as enzymes such as catalase, superoxide dismutase and various peroxidases. Low levels of antioxidants, or inhibition of the antioxidant enzymes, causes oxidative stress and may damage or kill cells.
As oxidative stress might be an important part of many human diseases, the use of antioxidants in pharmacology is intensively studied, particularly as treatments for stroke and neurodegenerative diseases. However, it is unknown whether oxidative stress is the cause or the consequence of disease. Antioxidants are also widely used as ingredients in dietary supplements in the hope of maintaining health and preventing diseases such as cancer and coronary heart disease. Although initial studies suggested that antioxidant supplements might promote health, later large clinical trials did not detect any benefit and suggested instead that excess supplementation may be harmful. In addition to these uses of natural antioxidants in medicine, these compounds have many industrial uses, such as preservatives in food and cosmetics and preventing the degradation of rubber and gasoline.
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News tagged with antioxidants
India's 'holy powder' finally reveals its centuries-old secret
Chemistry / Analytical Chemistry
Apr 20, 2009 |
4.7 / 5 (31) |
3
Scientists in Michigan are reporting discovery of the secret behind the fabled healing power of the main ingredient in turmeric — a spice revered in India as "holy powder." Their study on the ingredient, curcumin, ...
Probing Question: How do antioxidants work?
Aug 01, 2008 |
4.2 / 5 (27) |
1
Blueberries, pomegranates, green tea and dark chocolate -- these are just some of the antioxidant-rich "superfoods" found in almost any supermarket today. As well as improving our general health, there is growing evidence ...
New study on antioxidants shows mixed results for life extension
Biology /
Sep 30, 2008 |
4.6 / 5 (23) |
1
First the good news: a study by scientists at the Buck Institute for Age Research shows four common antioxidants extended lifespan in the nematode worm C. elegans. And the not such good news: those four were among 40 antioxidants ...
Nano-sized 'trojan horse' to aid nutrition
Nanotechnology / Bio & Medicine
Aug 25, 2008 |
3.9 / 5 (17) |
5
Researchers from Monash University have designed a nano-sized "trojan horse" particle to ensure healing antioxidants can be better absorbed by the human body.
Secrets of a Life-Giving Amino Acid Revealed
Jul 16, 2009 |
4.6 / 5 (10) |
0
(PhysOrg.com) -- Selenium is a trace element crucial to life -- too little or too much of it is fatal. In the July 17 issue of the journal Science, researchers at Yale University and University of Illinois at Chi ...
Chocolate rich in flavanols may protect the skin from UV
Nov 06, 2009 |
5 / 5 (9) |
3
(PhysOrg.com) -- A new study has discovered for the first time that dark chocolate rich in flavanols may provide significant protection from the harmful effects of ultraviolet light.
Humans don’t get all the benefit from raw tomatoes
Apr 23, 2009 |
4 / 5 (11) |
1
Eating a raw tomato may not be the best way to release all its healthy antioxidants into the body.
Brain plays key role in appetite by regulating free radicals
Jul 30, 2008 |
4.7 / 5 (9) |
0
Researchers at Yale School of Medicine have found the brain's appetite center uses fat for fuel by involving oxygen free radicals—molecules associated with aging and neurodegeneration. The findings, reported in the journal ...
Whole grain cereals, popcorn rich in antioxidants, not just fiber: study
Aug 18, 2009 |
4.4 / 5 (8) |
4
In a first-of-its kind study, scientists reported today at the 238th National Meeting of the American Chemical Society (ACS) that snack foods like popcorn and many popular breakfast cereals contain "surprisingly ...
Antioxidant controls spinal cord development
Medicine & Health / Neuroscience
Sep 18, 2009 |
4.9 / 5 (7) |
0
Researchers at the Johns Hopkins School of Medicine have discovered how one antioxidant protein controls the activity of another protein, critical for the development of spinal cord neurons. The research, publishing this ...
Scientists discover influenza's Achilles heel: Antioxidants
Oct 29, 2009 |
4.3 / 5 (7) |
1
As the nation copes with a shortage of vaccines for H1N1 influenza, a team of Alabama researchers have raised hopes that they have found an Achilles' heel for all strains of the flu—antioxidants. In an article appearing in ...
Plums Poised to Give Blueberries Run for the Money
Biology /
Jan 28, 2009 |
4.7 / 5 (6) |
2
There's an emerging star in the super-food world. Plums are rolling down the food fashion runway sporting newly discovered high levels of healthy nutrients, say scientists at Texas AgriLife Research.
Could antioxidants make us more, not less, prone to diabetes? Study says yes
Oct 06, 2009 |
2.7 / 5 (10) |
0
We've all heard about the damage that reactive oxygen species (ROS) - aka free radicals - can do to our bodies and the sales pitches for antioxidant vitamins, skin creams or "superfoods" that can stop them. In fact, there ...
New human study reinforces antioxidant benefits of tart cherries
Apr 19, 2009 |
5 / 5 (4) |
1
Eating just one and a half servings of tart cherries could significantly boost antioxidant activity in the body, according to new University of Michigan research reported at the 2009 Experimental Biology meeting in New Orleans.1 In the stu ...
Source of major health benefits in olive oil revealed
Apr 02, 2009 |
4.5 / 5 (4) |
0
Scientists have pinned down the constituent of olive oil that gives greatest protection from heart attack and stroke. In a study of the major antioxidants in olive oil, Portuguese researchers showed that one, DHPEA-EDA, protects ...
