Antioxidants and Free Radicals

See also:

• Antioxidants for Sports & Fitness

Free radicals are highly reactive compounds that are created in the body during normal metabolic functions or introduced from the environment. Free radicals are inherently unstable, since they contain "extra" energy. To reduce their energy load, free radicals react with certain chemicals in the body, and in the process, interfere with the cells' ability to function normally. Antioxidants work in several ways: they may reduce the energy of the free radical, stop the free radical from forming in the first place, or interrupt an oxidizing chain reaction to minimize the damage caused by free radicals.

Free radicals are believed to play a role in more than sixty different health conditions, including the aging process, cancer, and atherosclerosis.¹ Reducing exposure to free radicals and increasing intake of antioxidant nutrients has the potential to reduce the risk of free radical-related health problems.

Oxygen, although essential to life, is the source of the potentially damaging free radicals. Free radicals are also found in the environment. Environmental sources of free radicals include exposure to ionizing radiation (from industry, sun exposure, cosmic rays, and medical X-rays), ozone and nitrous oxide (primarily from automobile exhaust), heavy metals (such as mercury, cadmium, and lead), cigarette smoke (both active and passive), alcohol, unsaturated fat, and other chemicals and compounds from food, water, and air.

The body produces several antioxidant enzymes, including superoxide dismutase (SOD), catalase, and glutathione peroxidase, that neutralize many types of free radicals. Supplements of these enzymes are available for oral administration. However, their absorption is probably minimal at best. Supplementing with the "building blocks" the body requires to make SOD, catalase, and glutathione peroxidase may be more effective. These building block nutrients include the minerals manganese, zinc, and copper for SOD and selenium for glutathione peroxidase.

In addition to enzymes, many vitamins and minerals act as antioxidants in their own right, such as vitamin C, vitamin E, beta-carotene, lutein, lycopene, vitamin B2, coenzyme Q10, and cysteine (an amino acid). Herbs, such as bilberry, turmeric (curcumin), grape seed or pine bark extracts, and ginkgo can also provide powerful antioxidant protection for the body.

Consuming a wide variety of antioxidant enzymes, vitamins, minerals, and herbs may be the best way to provide the body with the most complete protection against free radical damage.

1. Ames BN, Shigenaga MK, Hagen TM. Oxidants, antioxidants, and the degenerative diseases of aging. Proc Natl Acad Sci 1993;90:7915-22.

Last Review: 09-07-2006

Copyright © 2007 Healthnotes, Inc.  All rights reserved. www.healthnotes.com

Learn more about Healthnotes, the company.

Learn more about the authors of Healthnotes.

The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires August 2007.

This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information. For more information, click here.