Antioxidants are vitamins or other nutrients that may protect the cells of the body against harm from free radicals, molecules that develop from metabolism of food or exposure to environmental toxins like smoke, pesticides or radiation. Free radicals injure cells and may contribute to heart disease, cancer, Alzheimer's disease and other conditions.
Types of Antioxidants
Antioxidants retard the oxidative injury that leads to disease in the body. According to the American Dietetic Association, antioxidants comprise different vitamins, minerals and other substances that perform multiple functions. Some categories of antioxidants include beta-carotene, lutein, lycopene, glutathione, copper, selenium, manganese, zinc and vitamins A, C and E.
Sources of Antioxidants
The Mayo Clinic advocates a diet rich in antioxidant-containing foods as the best approach to antioxidant intake. Food sources encompass thousands of different antioxidants, and come from fruits, vegetables, beverages, nuts and herbs. Common fruits containing antioxidants include berries, apples, avocados, cherries, pineapple and pears. Vegetables such as beans, artichokes, spinach, red cabbage, potatoes, tomatoes and broccoli also supply antioxidants. Beverage sources include green tea, red wine and fruit juices. Nuts with antioxidants include walnuts, pistachios, pecans, hazelnuts and almonds. Some common herb sources include cinnamon, ginger, dried oregano leaf and turmeric powder.
The Immune System
The immune system is comprised of cells, tissues and organs that operate to protect the body from "foreign" microbes and other substances. The immune system uses the lymphatic system to move white cells and waste through the body. Immune system dysfunction produces conditions like allergies, asthma, rheumatoid arthritis, osteoarthritis and immune deficiency disease. The immune system functions to keep the body healthy and free of infections.
Antioxidants and the Immune System
According to the "Indian Journal of Dermatology," antioxidant molecules such as vitamins E and C intermingle with free radicals and either eradicate them or reduce the damage they cause. Immune-enhancing diets containing antioxidants are linked to a significant reduction in infections in individuals undergoing vital elective operations, according to "Critical Care Clinics." The literature documents a multitude of studies supporting the positive effect of antioxidants obtained from dietary intake.
Supplemental Sources of Antioxidants
The Mayo Clinic says diet intake is the best source of antioxidants. Research over the last 20 years indicates that using antioxidant supplements fails to exert the same positive effects as dietary sources. In fact, the use of beta-carotene supplements produced more lung cancer in study participants taking the supplement to prevent cancer.
References
- MedlinePlus: Antioxidants
- American Dietetic Association: What is an Antioxidant?
- "Annals of Nutrition and Metabolism"; Contribution of Selected Vitamins and Trace Elements to Immune Function; E. S. Wintergerst et al.; 2007
- Mayo Clinic: Food Sources the Best Choice for Antioxidants
- American Heart Association: Antioxidant Vitamins
- National Institute of Allergy and Infectious Diseases: Immune System
