What are Antioxidants?
Growth, development, tissue repair, and aging are natural body processes that we experience day by day. However, these are also accompanied by metabolic by-products that include free radicals, which result from oxidative processes. In time, some of our cells are damaged and some become old, but our body continues to replace these cells. However, it is not as simple as that. Free radicals can damage our DNA, which controls almost every aspect of our well-being, and after a long time, premature aging and chronic disease can ensue.
Nature’s way of protecting us from premature aging and disease is by providing us with substances in our diet, which can help fight these free radicals. These substances are called antioxidants, because they help protect our bodies from the negative effects of oxidation. Antioxidants are found abundantly in nature, especially in fruit and vegetables. Although normal cell functions result in the production of small amounts of free radicals, which may be controlled by eating a healthy diet, other factors, such as cigarette smoke or pesticides or excess alcohol intake can accelerate cell damage. Free radicals can cause a chain of reactions that lead to significant DNA changes, which in turn, can result in cell mutations. Damaged cells can grow abnormally and reproduce abnormally, sometimes very quickly, causing disease. Therefore, health experts emphasize the importance of eating a healthy diet that includes a variety of nutrients and antioxidants.
Antioxidants reduce the damage caused by free radicals to your cells. These free radical scavengers include flavonoids, which make up the largest class of antioxidants, and polyphenols (or phenols), a smaller group of antioxidants. Some experts use other terms like phytonutrients and phytochemicals, which are generic terms used to describe chemicals and nutrients found in plants. However, aside from antioxidants that come from plants in our diet, some antioxidants are naturally produced by our bodies. Dietary supplements like vitamins and minerals are also important sources of antioxidants.
Antioxidants in the Diet
There are three major antioxidant vitamins found in the diet. These are beta-carotene (vitamin A), vitamins C and E. These are found in many colorful fruit and vegetables, most especially in those with red, orange, yellow, purple, blue hues.
Rich sources of beta-carotene (a provitamin A carotenoid) include apricots, asparagus, broccoli, beets, corn, cantaloupe, carrots, green peppers, mangoes, kale, turnip, collard greens, peaches, nectarines, pink grapefruit, squash, pumpkin, sweet potato, spinach, watermelon, tangerines, and tomatoes.
Vitamin C-rich foods include berries, broccoli, cantaloupe, cauliflower, Brussels sprouts, grapefruit, honeydew, kiwi, kale, mango, nectarine, papaya, orange, snow peas, strawberries, sweet potato, tomatoes, red, green, and yellow peppers.
Excellent sources of vitamin E are broccoli, carrots, mustard, chard, turnip greens, nuts, mangoes, papaya, pumpkin, spinach, red peppers, and sunflower seeds.
Other antioxidants include flavonoids, which are found in various berries, coffee, and tea, and phenols, which are found in many fruits, vegetables, nuts, and herbs. Minerals that have strong antioxidant properties include zinc, which may be found in oysters, seafood, poultry, red meat, dairy products beans, nuts, whole grains, and fortified cereals; and selenium, which is found in brazil nuts, tuna, poultry, beef, and fortified breads.
According to the US Department of Agriculture, there are 20 foods with the highest antioxidant capacities compared to other foods. These top 20 antioxidant-rich foods were identified after researchers evaluated more than 100 types of foods. They found that blueberries, blackberries, and cranberries rank highest in antioxidant capacity among the fruits they studied. Among the vegetables, artichokes, beans, and Russet potatoes ranked highest while hazelnuts, pecans, and walnuts topped the nuts category. Other antioxidant-rich foods include apples, cherries, plums, and prunes. However, the health benefits we obtain from foods depend on many factors, including the amount we eat and how our body absorbs the nutrients we consume. Health experts recommend eating a variety of nutrient-dense foods that are low in calories, sugar and fat. It is also important to avoid foods that can potentially harm the cells, such as fried foods, sugary beverages, and other unhealthy foods.
Most doctors recommend eating a healthy, balanced diet to obtain most of the nutrients the body needs to maintain health and prevent disease. However, some may also recommend taking health supplements such as multivitamins and minerals when one has a nutritional deficiency that cannot be corrected by a healthy diet alone. Needless to say, health supplements must not take the place of a balanced diet and a healthy lifestyle. Consumers are also warned to take nutritional supplements cautiously, to take them only as directed, and to inform their doctors of their use, especially if they are taking other medications for certain health conditions.
This information should not take the place of medical advice. We encourage you to talk to your health care providers (doctor, registered dietitian, pharmacist, etc.) about your interest in, questions about, or use of dietary supplements and what may be best for your overall health.
NCI. Antioxidants and Cancer Prevention. http://www.cancer.gov/cancertopics/factsheet/prevention/antioxidants
WebMD. How Antioxidants Work. http://www.webmd.com/food-recipes/features/how-antioxidants-work
WebMD. Super Foods for Optimal Health. http://www.webmd.com/food-recipes/antioxidants-your-immune-system-super-foods-optimal-health
WebMD. 20 Common Foods With the Most Antioxidants. http://www.webmd.com/food-recipes/20-common-foods-most-antioxidants