News tagged with antioxidants

Related topics: heart disease

Antioxidants—too much of a good thing?

In older men, a natural antioxidant compound found in red grapes and other plants—called resveratrol—blocks many of the cardiovascular benefits of exercise, according to research published in The Journal of Physiology.

Jul 22, 2013
popularity 4.2 / 5 (13) | comments 0 | with audio podcast

Copper on the brain

(Medical Xpress)—The value of copper has risen dramatically in the 21st century as many a thief can tell you, but in addition to the thermal and electrical properties that make it such a hot commodity metal, ...

May 27, 2013
popularity 5 / 5 (4) | comments 0 | with audio podcast

Antioxidant

An 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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