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Antioxidants

What Is It?

Anti-oxidants are substances intended to control a biological phenomenon called oxidative stress. Oxidative stress is a natural consequence of the use of nutrients by human cells. The molecules that make up cells contain pairs of electrons. These balanced pairs can be disrupted during the burning of energy in the cell, and single unpaired electrons will begin to fly around the body. These unpaired electrons will also attempt to steal paired electrons from other molecules, setting in motion a chain reaction. During this process much damage can be caused to the cell, including its genetic template, the DNA. Free radicals also damage the membrane of a cell, disrupting its absorption of nutrients and other functions essential to the health of a cell.

Free radicals are like the sparks produced by a fire: random and dangerous, but inevitable. Most of these free radicals are mopped up by anti-oxidant substances like glutathione, vitamin E, vitamin C, beta carotene, superoxidedismutase (SOD) and various amino-acids. However, some bodily processes like fighting infection produce far greater quantities of free radicals than the body's anti-oxidant stores can cope with. Polluted air, water and food, cigarette smoke, recreational and treatment drugs are also potent sources of free radicals.

Laboratory studies suggest that oxidative stress boosts HIV replication and in turn HIV replication boosts the production of free radicals, causing more oxidative stress. In particular, laboratory studies have shown that free radicals activate NF-kB, a cell protein which can trigger HIV to replicate where it has lain dormant in the cell's DNA. NF-kB production can be suppressed by some antioxidants. But when HIV genes become activated, levels of anti-oxidants in cells become drastically depleted as free radical production is stepped up.

Until now almost all research has concentrated on the relationship between oxidative stress and HIV, but HIV is not the only factor to influence free radical production in people at risk of developing AIDS. Increased activity by neutrophils white blood cells which fight bacterial and fungal infections boosts levels of free radicals, as does chronic inflammation of tissues. Oxidative stress itself contributes to inflammation at many sites in the body, which then starts another cycle of free radical release.

NF-kB also triggers cytomegalovirus (CMV) and Epstein-Barr virus (EBV) to reproduce, setting off another cycle of damage, since both viruses can trigger dormant HIV as well as causing oxidative stress and disease in their own right. Sexually transmitted infections, repeated antibiotic use, recreational drugs such as poppers and poor nutrition also increase the likelihood of high levels of free radical activity.

Free radicals have also been implicated in apoptosis or `programmed cell death'. Programmed cell death occurs when a T-cell takes the wrong cue from an antigen-presenting cell, which ought to alert T-cells to the presence of infections. When presented with an antigen in this way, a T-cell should take note of the antigen and become primed to proliferate and kill whenever it encounters that antigen in the future. Sometimes however, T-cells do not respond. They become anergic (literally meaning that they have no energy) and the next time they encounter the antigen which triggered their anergic state, they commit suicide. This is programmed cell death.

This process can be measured because it leaves cellular DNA chopped up in a very distinctive way. Researchers have noted that in people with HIV, a high level of apoptosis can occur which kills many T-cells even though they are never directly infected with HIV. The exact role of HIV in this process has still to be clarified. French researchers who have led the field in this area believe that free radicals play a key role in apoptosis.

One theoretical approach to treatment for people with HIV is to try to boost levels of anti-oxidants in the body. One important anti-oxidant is glutathione (GSH) which is essential for the proper functioning of T-lymphocytes; it is thought to play an important role in cellular immune responses and prevent the activation of cells that are latently infected with HIV. Glutathione itself is very poorly absorbed as a supplement. Instead, many PWAs have used NAC, a cysteine precursor. The drug provides cysteine, which is converted into glutathione in the liver.

Over the last several decades, scientists have discovered that the body's formation of unstable oxygen molecules called free radicals is unavoidable--every cell produces tens of thousands of them each day. We're also exposed to free radicals in the environment on a daily basis. Cigarette smoke, for instance, is one of the most concentrated sources of free radicals. 

Left unchecked, free radicals can cause extensive cell damage and contribute to a whole list of chronic diseases. Luckily, the body does have a defense system against these rogue "oxidant" compounds: antioxidants. Found in numerous fruits and vegetables, and even produced naturally by the human body, antioxidants literally "mop up" free radicals. 

The more familiar antioxidants include vitamins E and C; the carotenoids (such as beta-carotene); selenium; and flavonoids (anthocyanidinspolyphenolsquercetin). All of these are readily supplied by a varied and well-balanced diet. Probably lesser known are the so-called "factory-installed" antioxidants produced by the body itself; these include glutathione, alpha-lipoic acid, and coenzyme Q10

Antioxidants in the form of dietary supplements have been available for years, and while they can't substitute for a healthy diet and lifestyle, they can play a role in reinforcing your overall health and resilience. Antioxidant supplements are best taken in the form of combination products because multiple antioxidants appear to work together synergistically far more effectively than a single antioxidant, no matter how high the dose. In addition, some supplements, such as zinc, copper, and selenium, are necessary to actually strengthen the body's own antioxidant protection system. 

Most antioxidant combinations contain a standard ingredient base, namely vitamin C, vitamin E, beta-carotene, and the mineral selenium. After that, there is a great deal of variation. Some combinations include newly discovered antioxidants, such as proanthocyanidins (flavonoids found in grape seed extract, pine bark, and red wine), N-acetylcysteine (NAC), alpha-lipoic acid, coenzyme Q10, and zinc. Others feature potent herbal antioxidants such as ginkgo biloba or green tea. 

Health Benefits

When you have too few antioxidants to counteract your free radicals, significant damage can occur, leading to a variety of chronic degenerative diseases, ranging from stroke and fibromyalgia, to sinusitis, arthritis, vision problems, and even Parkinson's and Alzheimer's disease. A poor diet, cigarette smoking, environmental pollutants, and ultraviolet (UV) radiation from the sun also increase the free-radical load, creating a situation known as "oxidative stress." 

Ongoing research, however, indicates that a high antioxidant intake really does help stave off some of these illnesses, specifically the risk of various cancers--those of the stomach, prostate, colon, breast, bladder, and pancreas among others--over a person's lifetime. Antioxidants also appear to boost overall health and resilience. 

Specifically, antioxidants may help to: 

Prevent heart disease. Antioxidants such as vitamin E halt the oxidation of LDL ("bad") cholesterol. This is beneficial because once LDL is oxidized it can become trapped in the artery walls, damaging the lining of the artery and leading to the accumulation of fatty deposits called plaque. Eventually, plaque can build up so much that it narrows the space within the artery. Blood clots may form on the plaque and completely block the flow of blood. In a coronary artery, this will cause a heart attack. In an artery within the brain, the result is a stroke. 

Control high blood pressure. By scouring out the free-radical molecules that can cause oxidative damage (to LDL or "bad" cholesterol, specifically), antioxidants help your blood vessels stay flexible and able to dilate, which in turn helps keep your blood pressure from worsening. 

In fact, until recently scientists believed that regular intake of vitamin C, a major antioxidant, could help lower blood pressure by widening blood vessels. Several studies seemed to indicate that this was true. However, a new study has found that vitamin C may actually speed up--not slow down--hardening of the arteries. Until more about this surprising association is understood, it's probably best to opt for a mixed combination of antioxidants rather than single, high doses of vitamin C. 

Protect against diabetes-related damage. One of the reasons that diabetes is so important to monitor closely is that it can affect so many organ systems: eyes, kidneys, blood vessels, heart. It's thought that the altered metabolic state brought about by diabetes produces free radicals, which in turn are responsible for these types of damage. That's why it makes so much sense, especially if you have diabetes, to use antioxidants to reinforce your defense system against free-radical damage. 

Block the development of certain cancers. Stomach, prostate, colon, breast, bladder, esophageal, and pancreatic--these are just a few of the types of cancer that may be prevented by antioxidants. In a comprehensive review of 130 studies examining the connection between diet and cancer, researchers at the University of California at Berkeley found that 92% of the studies showed that taking antioxidant supplements or eating antioxidant-rich foods significantly reduced the risk of cancer. 

Slow the effects of aging. According to one theory, antioxidants may impede the excessive formation of free radicals that probably play a part in the wrinkling of skin, loss of muscle elasticity, reduced immunity, and memory failures. So although you can't completely prevent aging, you may be able to minimize some of its effects with antioxidants. 

Dosage Information

Special tips:

--Take a high-potency multivitamin/mineral and a well-balanced antioxidant complex every day. It may be necessary to adjust the dosages outlined below to account for your own daily vitamin regimen. All of these supplement recommendations also assume you are eating a healthful diet. 

--Opt for an antioxidant combination product rather than a single antioxidant supplement. The latest studies indicate that a single antioxidant at high doses will not provide the same degree of protection as a combination of antioxidants. In fact, a single antioxidant used by itself may be harmful, becoming a free radical itself. When other antioxidants are present, they all help recycle each other. Combination products are also more convenient and less expensive than individual antioxidants. 

For general good health: Look for an antioxidant complex that contains at least the nutrients listed here in the recommended dosage. Combination products vary considerably. In general, look for a product that will increase the number of different antioxidants you take each day rather than simply duplicating those already found in your daily multiple vitamin. 

Basic antioxidant vitamins:

"Enriching" antioxidants:
Guidelines for Use

·Take antioxidant supplements with meals. Foods that contain a little bit of fat enhance the absorption of vitamin E and carotenoids

·It's best to take antioxidant supplements in two doses during the day. That way, you are constantly providing your body with a fresh supply. 

·Opt for natural vitamin E supplements. Studies show that E derived from natural sources is better absorbed than synthetic forms of the vitamin. But don't rely simply on the word ''natural'' on the label. Check the ingredient list for d-alpha tocopherol (a natural form of vitamin E). Don't buy those that contain dl-alpha tocopherol

·In addition to antioxidant supplements, it is important to include plenty of vegetables, fruits, and other plant foods in your diet. Many of the flavonoids are not available in supplement form, and there are probably many undiscovered beneficial compounds in plant foods. 

A number of important antioxidants are found in foods: 

General Interaction

·People on anticoagulant drugs should talk to their doctor before taking antioxidant complexes containing more than 400 IU of vitamin E. This popular antioxidant can have an anticoagulant effect of its own when taken in higher doses. 

·Cancer patients undergoing chemotherapy should talk to their oncologists about antioxidant supplementation. 

Cautions

·Antioxidant combinations are extremely safe and virtually free from side effects. Some people with sensitive digestive systems get mild nausea or upset stomach with virtually any nutritional supplement, so your best bet is to take supplements with food and avoid taking them on an empty stomach. 

·Antioxidant combinations are safe to use during pregnancy and when breast-feeding. 

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