Cell damage in the human body is responsible for cancer, heart ailments such as stroke, ageing and a host of different diseases. During several processes which take place in our cells, the body produces naturally a molecule with uneven electrons called the “free radicals”. This can also occur when the body needs to neutralize bacteria and viruses or also during endurance exercise, when the body needs additional oxygen and produces more free radicals. The free radicals need to complete their electrons and will try to “steal” electrons from another molecule and by doing so make those molecules become a free radical in themselves. This starts a chain reaction which, in time, can lead to irreversible DNA damage, cell deficiencies and death of vital cells and so aids or causes the above mentioned diseases.
In general antioxidants are plentiful in vegetables and fruits, seeds and nuts and even in some poultry, fish and meats.
External factors such as pollution, cigarette smoke and radiation can also aid the production of free radicals. Although the human body does have some mechanisms to combat free radicals, it is incapable of producing antioxidant and therefore antioxidants need to be consumed within our daily diet.
Antioxidants are organic substances such as Vitamins A (1,2&3, including beta-carotene), C and E, the mineral selenium and the carotenoids, lycopene and lutein. These help neutralize the free radicals and as such can help prevent cancer, some heart diseases and strokes.
In general antioxidants are plentiful in vegetables and fruits, seeds and nuts and even in some poultry, fish and meats. However, a number of factors can diminish the content of antioxidants in fruit and vegetables; the concentration of vitamins in parts of some fruits and vegetables, the fact that different minerals and substances are either water soluble or can be damaged by water and light, frost or heat, and also peeling and prolonged cooking. While eating the products raw certainly would be best, it is better to cook vegetable whole (baking a pumpkin or cooking a potato with the skin on) and for as short a time as possible to minimize the loss of vital nutrients.
When planning meals, one should give great care to a balanced meal, perhaps with sources of antioxidants in mind. Not all antioxidants are equally active for all free radicals. The listing below provides some information as to the vitamins and minerals present in some vegetables and fruits.
Vitamin A (1,2&3)
Milk and milk products, such as cheese, butter and yoghurt, liver and egg yolk and beet leafs.
Beta-carotene is a pro-vitamin, which in the human body is converted to vitamin A. Beta-carotene is responsible for the orange color of vegetable and fruits and mainly present in carrots, cantaloupe, squash and pumpkin, apricots, mangoes and sweet potatoes. Spinach, kale, arrugola, broccoli, and other green leafy vegetables are also good sources of beta-carotene.
All Citrus fruits, kiwi, berries, red and yellow capsicum, beetroot, pineapple, guava, mango, tomato and papaya provide vitamin C in abundance. Spinach, asparagus, green peppers, Brussels sprouts, watercress and other green herbs and vegetables are also rich in vitamin C. Moderate amounts of vitamin C can also be found in meat, poultry and fish.
Some nuts and seeds such as almonds, hazelnuts, peanuts, sunflower seeds and their products or oils; legumes such lentils, peas and beans and soya bean, olive and safflower oil, wheat germ, brown rice and oatmeal are very good sources of vitamin E. Also mangoes and kiwi, broccoli and spinach have useful amounts of vitamin E.
Lutein and Lycopene
Both these substances belong to the carotenoid family. While lutein is mainly found in collard greens, arrugola, mangold, spinach, kale and other green leafy vegetables.
Lycopene is mainly present in red fruits and vegetables such as watermelon, tomatoes, blood oranges, guava, apricots and pink grapefruits.
Unlike all the other antioxidants, selenium is a nonmetallic mineral related to sulfur and not a nutrient. Selenium is part of the soil plants are planted in and it is the “selenium richness” of the soil which determines the amount of the mineral present in the crop. In general, Brazil nuts, rice, grains, wheat, chicken, egg, dairy products, onion and garlic are good sources of selenium. Also seafood such as tuna, salmon, crab and lobster have high contents of selenium.