Department of Food Science and Human Nutrition
Extension
Colorado State University
Fort Collins, CO 80523-1571
Healthy Heart Beats
April-June 2008
Vol 30, Issue 2
Did You Know?....
Q: I have heard a lot about antioxidants in the news. Are they good for me and should I take them in pill form or increase my fruit and vegetable intake?
A: Antioxidants have been making headlines for their role in protecting our cells from potentially damaging molecules called free radicals. Cell damage from overexposure to free radicals is associated with the aging process, cancer, cardiovascular disease, and hypertension. Free radicals exist both in our environment and in our bodies. We are environmentally exposed to them through ozone, air pollution, radiation, and cigarette smoke. The immune system is the main body system that utilizes free radicals.
The typical calorie-rich, nutrient-poor American diet produces an overabundance of free radicals which puts us at risk. Fruits and vegetables are a rich source of nutrients that act as antioxidants, including beta carotene and vitamins A and C. Is it a good idea to pop a pill instead? Media has popularized supplements as a quick and easy way to ingest a large level of antioxidants. Despite the popularity of these supplements, they are not recommended by nutrition professionals. There is no solid evidence to show that antioxidant pills are effective at reducing health risks. A recent article published in the Mayo Clinic Proceedings showed that across twelve clinical trials, antioxidant use did not diminish incidence of cancer and mortality from cancer, and beta carotene increased these risks among smokers.
Additionally, there are serious health consequences to overdosing on supplements. Vitamins A and E are fat soluble and an excessive intake can cause a large amount to accumulate in fat with the possibility of toxicity. Too much vitamin A over time (upper limit is 3000 micrograms or 10,000 IU per day) can cause toxicity with the following symptoms: liver abnormalities, nerve damage, and birth defects. Overdosing on vitamin E (upper limit is 1000 milligrams or 1500 IU per day) can cause increased risk of bleeding. While Vitamin C is water soluble, overdosing (upper limit is 2000 mg per day) can damage the kidneys since they have to work overtime to excrete it. Remember, free radicals do perform important functions in our bodies. Rather than "purge" our system of antioxidants, we should protect ourselves from overexposure to free radicals by consuming a diet rich in fruits and vegetables.
Want more reasons to eat fruits and vegetables? The exact ways that antioxidants protect our bodies is still being researched, but fruits and vegetables contain many other compounds and nutrients which may help to make antioxidants more available to you. These compounds are not present in supplements, possibly making supplements less effective than eating fruits and vegetables. The DASH (Dietary Approaches to Stop Hypertension) diet calls for four to five servings each of fruits and vegetables as the antioxidant properties help to lower blood pressure. Additionally, generous consumption of fruits and vegetables contributes to an overall lower fat and lower calorie diet. The answer to your question is to enjoy the flavors of a variety of colorful fruits and vegetables--try new ones, add more to your recipes, and snack on them to get the maximum benefits of antioxidants. Don't waste your money on antioxidant supplements.
Source: Mayo Clinic Proceedings, 2008, 83(1): 23-34 (January).
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