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Antioxidants

Description

The environment we live in is a major source of free radicals. Cigarette smoke, radiation, sun exposure, chemicals, pesticides, herbicides, trans-fatty acids, heavy metals, pollution and alcohol are all sources of free radicals that our bodies are exposed to daily. Free radicals have been implicated in many diseases and conditions, including heart disease, cancer and aging. Antioxidants can protect the body from these potentially harmful substances. Antioxidants are agents that fight the damaging process of oxidation, which batters the cell’s integrity. Cells get damaged, or oxidized, because they are attacked by free radicals. Free radicals are molecules with a free electron in their outer shell which makes them highly reactive with other cells. When a free radical comes in contact with another cell, it will attack it, oxidize it, and cause damage. If free radicals are not stopped, they can start a long chain reaction of free radical formation which can result in the oxidation of the cell membrane, otherwise known as, “lipid peroxidation." This oxidation can cause rupturing of the cell membrane, leading to cell death. When cells are oxidized by free radicals, the cellular damage they cause can be responsible for a wide variety of disease symptoms. This is where the antioxidants come in. Antioxidants will fight free radicals and prevent the damaging oxidation from taking place. The antioxidants work synergistically to protect cells; some work better in a water environment (such as the inside of cells), like vitamin C. Some, like vitamin E, work in a lipid environment (such as the cell membrane made of lipids). Some, like beta carotene, work in areas of low oxygen tension, making beta carotene a good antioxidant for the lungs and blood, where tissue oxygen exchange is being conducted. Antioxidants can be nutrients, like certain vitamins, minerals, phytochemicals, etc., or they can be enzymes. Some of the antioxidant vitamins are vitamins C, E, and beta carotene. Antioxidant minerals are selenium and zinc, which have free-radical quenching ability in addition to being integral parts of the antioxidant enzyme system. Antioxidant enzymes include superoxide dismutase (which fights the superoxide radical and can include zinc or copper in its structure), and glutathione peroxidase (which includes selenium as an integral part of the enzyme). Certain phytochemicals (plant nutrients) have free radical-scavenging qualities. The bioflavonoids found in plants, for instance, have antioxidant activity. The highly potent proanthocyanidins (i.e. bioflavonoids found in deeply colored fruits and vegetables, grape seed extract, pine bark etc.) have recently been researched for antioxidant potential which may even exceed that of the powerful antioxidants like vitamins C and E. Quercetin is another flavonoid which seems to possess potent antioxidant activity. There is a long list of herbal plants possessing antioxidant activity, and many times the activity is due to the high content of flavonoids such as quercetin. Ginkgo biloba, for instance, contains quercetin, proanthocyanidins and other flavonoids and plant constituents, and is well-known as a potent antioxidant. Even some spices contain antioxidant activity, such as curcumin, cloves, and turmeric. Additional nutrients possessing antioxidant properties are co-enzyme Q 10, glutathione and n-acetyl cysteine, among others.

Signs and Symptoms for Nutrient Applications

Antioxidant supplementation can be used daily for preventative care or as a cancer therapy adjunct. Antioxidants can also be beneficial in conditions associated with free radical damage (heart disease, respiratory problems, etc.). Different antioxidants all work together in their different capacities to guard against free radicals and protect cells from oxidative damage. This protection keeps cells from aging and dying, which reduces the susceptibility to disease. A potent antioxidant combination will provide a comprehensive defense against free radical damage. Free radical damage can cause and/or accelerate many diseases.

Clinical Applications/Research

Beta-carotene or Mixed Carotenes

Beta-carotene works in areas of low oxygen tension, making beta carotene a good antioxidant for the lungs and blood, where tissue oxygen exchange is being conducted. Mixed carotenes include beta carotene, as well as other natural carotenoids.

Vitamin C

Vitamin C is a powerful, water-soluble antioxidant. It is responsible for regenerating oxidized vitamin E in the body.

Vitamin E

Vitamin E is a potent, fat-soluble antioxidant. Vitamin E protects the lipid portion of the cell membrane against heavy metals, chemicals, drugs and radiation. It is also important to proper immune function.

Selenium

Selenium is a potent antioxidant and detoxifier of a number of environmental pollutants. Selenium is part of glutathione peroxidase, a potent detoxifying enzyme.

N-acetyl-cysteine

N-acetyl cysteine, otherwise known as NAC, is a stable derivative of the amino acid cysteine, which has antioxidant properties and makes up part of the tripeptide glutathione. Glutathione, along with NAC, are powerful antioxidants. The cysteine is rapidly converted to glutathione, which hooks onto the toxic compound formed by acetaminophen degradation, makes it water-soluble, and facilitates excretion. By the same mechanism, NAC removes carcinogenic agents by binding to them and allowing the body to remove them. Principal uses of NAC include: liver toxicity, acetaminophen poisoning, chemotherapy, detoxification, respiratory problems, heart disease, and gallstones. NAC has also been shown to decrease mucus production (double blind studies has found that NAC supplements improved symptoms in individuals with bronchitis).

Ginkgo Biloba

There is a long list of herbal plants possessing antioxidant activity, and many times the antioxidant activity is due to the high content of flavonoids such as quercetin. Ginkgo biloba, for instance, contains quercetin, proanthocyanidins and other flavonoids and plant constituents, and is well-known as a potent antioxidant.

Green tea

Green tea is another potent antioxidant and has a much greater in vitro antioxidant capacity than black tea (Serafini 1996, Langley-Evans). In decreasing order of potency, epigalocatechin gallate, epicatechin gallate, epicatechin, catechin, and epigallocatechin are the main antioxidant constituents found in green tea (Osada K, et al, Tea catechins inhibit cholesterol oxidation accompanying oxidation of low density lipoprotein in vitro. Comp Biochem Physiol C Toxicol Pharmacol. 2001 Feb;128(2):153-164).

Contraindications/Toxicology

Extremely high doses of NAC (1.2 grams or more) for long term may increase oxidative damage and may be toxic to nerve cells in rats. Since ginkgo exhibits antiplatelet activity, it should not be used in combination with anticoagulant drugs. High dose vitamin C is not recommended in iron overload disease and kidney stone formers.

Disclaimer: The statements above have not been evaluated by the FDA. The nutritional suggestions and research provided are for informational purposes only and are not intended to diagnose, treat, cure or prevent disease and should not be used as a substitute for sound medical advice. Please see your health care professional in all matters pertaining to your physical health.

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