Saturday, July 19, 2008

Antioxidants: Protection from cancer-causing free-radicals with antioxidants contained in vitamin C, Pycnogenol and various herbs (Part I)

Ann, who has a tendency to overeat, also enjoys several glasses of wine with dinner. Slightly overweight, she "balances" her occasional ice cream binges with lots of vitamins, especially vitamins C and E. Her cousin Alison, who lives in a populous city, spends two hours in her car each day commuting to and from work. Because one of the women in her car pool smokes cigarettes, she opens the windows to allow the smoke to escape. Alison takes beta carotene (a precursor to vitamin A) sporadically, because she's not sure if it helps or hinders health.

Ann's husband, Warren, is a marathon runner who logs an average of 50 miles weekly to keep in shape. Because he believes his diet is healthy and balanced, he doesn't take any vitamin supplements.

Overeating and becoming overweight. Alcohol consumption. Air pollution. Cigarette smoke. Excessive exercise. Are these people consuming enough toxin-fighting antioxidant vitamins to effectively ward off free radicals, toxins produced by cells in our body by ... well ... living?

The answer isn't easy. Why? Because each day we are exposed to toxins from an array of sources-from food to pesticides and air pollution-as well as free radicals produced by our bodies when we gain weight-even when we breathe. In short, toxins and free radicals are impossible to avoid. How well we thwart these pollutants depends largely on genetics, lifestyle, environment-and the antioxidants in our diet.

Outsmarting the Outlaw

By now, most of us know about antioxidants, protective chemicals such as beta carotene, and vitamins C and E. During the past decade, these star nutrients have been charged with the ability to protect our health by arresting the production of free radicals. Specifically, antioxidants "work by allowing themselves to be attacked and damaged by free radicals, sparing the cell itself," explains Neal Barnard, MD, in Food for Life (Harmony Books, 1993).

Left unchecked, free radicals can rob our health by "rusting" our cells. Over time, this can leave us vulnerable to a plethora of health problems. Indeed, excess free radical production has been linked with more than 50 ailments, ranging from premature aging and clogged arteries (atherosclerosis) to cataracts and cancer.

Putting a break on the health-robbing abilities of free radicals isn't always easy-after all, they're a natural by-product of breathing, as well as our external environment. But if you know which antioxidants to consume, how much, and how often-based on your own personal lifestyle-you can begin to outsmart these outlaws.

ACE Antioxidants

Pioneering antioxidant and exercise researcher Kenneth Cooper, MD, MPH, calls antioxidants a "police force" that can reduce free radical production. The most important, he believes, are "exogenous (outside) antioxidants," especially vitamin C, vitamin E, and beta carotene.

At the Cooper Aerobics Center in Dallas, Texas, Dr. Cooper and his associates support an antioxidant-rich diet-especially abundant in fruits and vegetables, but also whole grains, legumes (beans and peas), and nuts and seeds. Says Ted Mitchell, MD, medical director for the Cooper Wellness Program: "The fact of the matter is, we form free radicals literally thousands of times every day. What we're hoping to do with antioxidants-whether through diet, which is the preferred way, or through vitamin supplements-is to reduce [the harmful] effects somewhat." He adds: "It's important to understand, though, that people in this field are feeling their way" [to optimal doses].

Supplements or no supplements? This is the question that lies at the core of the antioxidant debate. While most health care professionals recommend obtaining antioxidants from the foods we eat, only about 10 percent of Americans eat the recommended five or more servings of antioxidant-rich fruits and vegetables daily. "If you work at accenting fruits and vegetables in your diet," says Dr. Mitchell, "you can get enough beta carotene and vitamin C. But it's harder to get an adequate intake of vitamin E." Found in high quantities in nuts, seeds, and plant oils, "by the time you get enough to have sufficient antioxidant properties, it's likely you've overrun your calorie and fat count for the day."

Perhaps to compensate for our typically low intake of fruits and vegetables-and ensuing low antioxidant levels-many Americans have turned to supplements. Indeed, current reports indicate we spend $1.5 billion annually on vitamin, mineral, and herbal supplements. Vitamin C supplements remain the best-seller, but lately vitamin E has been gaining on C as our most popular antioxidant vitamin tablet or capsule.

Is obtaining antioxidants through vitamin supplementation both safe and effective? Yes and no-depending on which research you review. Some scientists do not recommend supplementation, and others embrace it as smart health "insurance," while a third camp takes still another approach, believing the ideal is to combine a health-smart diet together with moderate amounts of antioxidant supplements to enhance health.

Vitamin C Revived

Vitamin C is currently America's most popular antioxidant supplement. Millions of us take daily doses well above the recommended daily allowance (RDA) of 60 mg-with no known side effects (probably because the body eliminates excesses). Indeed, research has shown doses between one to six grams a day may lessen both the symptoms-and duration-of colds (Journal of the American College of Nutrition, 1995). (This study "overturns" two decades of research that disputed two-time Nobel-Laureate Linus Pauling's claim that megadoses of C are safe and can reduce the symptoms of colds.)
Beta Carotene Blues

Of the three major antioxidants, it is perhaps beta carotene that has received the most critical media attention. Concerns first surfaced in 1994, when a six-year-long research project from Finland linked supplemental beta carotene taken by cigarette smokers to a higher risk of lung cancer.

Then earlier this year, the National Cancer Institute (NCI) developed similar concerns about beta carotene supplementation. Like the Finnish study, the NCI's Beta Carotene and Retinol Efficacy Trial (CARET) was designed to explore the influence of beta carotene (and vitamin A) as preventive agents for lung cancer in high-risk men and women (i.e., heavy smokers and asbestos workers). But four years into the study, investigators terminated the study, believing the beta carotene supplements may actually be doing harm. Another NCI study, the 12-year Physician's Health Study (PHS), which examined 22,000, mostly non-smoking, male physicians who were taking beta carotene every other day, showed neither benefit nor harm from beta carotene supplementation.

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