Antioxidants
What are Antioxidants?Naturally OccurringTomatoes
Natural occurring antioxidants
One simple way, for example, of stopping apples going brown is to add a small amount of lemon juice. The ascorbic acid (vitamin C) contained in many citrus fruits is a natural antioxidant and for this reason finds frequent use in food production (E 300-E 304). Vitamin C and its various salts are added to protect soft drinks, jams, condensed milk and sausage.
Other natural antioxidants are the tocopherols (E 306-E309), which are members of the vitamin E family. Tocopherols are found mainly in nuts, sunflower seeds and soya and maize shoots, and they are mostly used for preserving vegetable oils, margarine and cocoa products.
Since both compounds are very popular antioxidants and the requirements for them cannot be met completely from natural sources, ascorbic acid and tocopherols have also been produced artificially for quite some time. It is nowadays possible to copy the molecular structure of these compounds so closely that there are no longer any differences in either structure or effects, which means that these “nature-identical” substances are essentially identical to their originals.
People must breathe in oxygen to live. Continuously on the move in the blood stream and transported to every cell, oxygen is necessary for all essential bodily functions. However, a small amount of this oxygen gets loose and produces unstable by-products called free radicals. Body processes, such as metabolism , as well as environmental factors, including pollution and cigarette smoke, can produce free radicals. An overload of free radicals in the body causes damage to the cells, ultimately resulting in disease and accelerated aging.
Antioxidant-rich food may help prevent various cancers, heart disease, and diseases of aging. Vitamins C and E, carotenoids (including beta-carotene), and the mineral selenium are all powerful antioxidants found in food. Vitamin C, a water-soluble vitamin, is also known as ascorbic acid. Most of the vitamin C in the diet (90%) comes from fruits and vegetables. However, since vitamin C is water soluble, cooking can destroy the vitamin C in a food.

Cigarette smoke, including second-hand smoke, is a major source of free radicals. These volatile molecules can damage tissues and cause disease.
Vitamin E, also known as alpha tocopherol, is a fat . Because vitamin E is found in oils, people who follow a low-fat diet may not get enough. Beta-carotene is a member of the carotenoid family. Found mainly in plants, carotenoids provide the vibrant red, yellow, green, and orange colors of fruits and vegetables, with carrots being a major contributor of beta-carotene. Typically, beta-carotene is a conditionally essential nutrient , but when one’s intake of vitamin A is low, beta-carotene becomes an essential nutrient, meaning that it must be obtained from food and cannot be manufactured by the body.
Selenium is an essential trace mineral ( trace minerals are needed only in small amounts). The amount of selenium found in food is directly related to the amount of selenium in the soil in which the food was grown. It is necessary for healthy immune function and is tied to killer-cell activity and antibody production. The many health benefits of the various antioxidants can be provided by a variety of food sources.
More and more functional foods contain combinations of various supplements. As popular as antioxidants are, an excess amount of them can be toxic. One reason to obtain antioxidants from food is that high doses may actually promote free radical production, also known as pro-oxidation, increasing the chance for health problems. Those who may benefit most from antioxidants include people dealing with a lot of stress , dieters limiting their calories to 1,200 per day or less, people on a low-fat diet, smokers, older adults, and people with a family history of heart disease or cancer.












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