- The process of oxidation in the human body produces unstable chemicals called free radicals, which damage cell membranes and other structures.
- Free radicals have been linked to a variety of diseases, including heart disease and certain cancers.
- Antioxidants are compounds in foods that scavenge and neutralise free radicals.
- Evidence suggests that antioxidant supplements do not work as well as the naturally occurring antioxidants in foods such as fruits and vegetables.
Oxidation can be accelerated by stress, cigarette smoking, alcohol, sunlight, pollution and other factors. 压力，抽烟，喝酒，UV，污染都会加速氧化。。也就是衰老变快。。赶紧多吃维C顶住。。
The effect of free radicals
Some conditions caused by free radicals include:
- deterioration of the eye lens, which contributes to blindness 加速近视
- inflammation of the joints (arthritis) 关节炎
- damage to nerve cells in the brain, which contributes to conditions such as Parkinson’s or Alzheimer’s disease 变笨
- acceleration of the ageing process 加速变老
- increased risk of coronary heart disease, since free radicals encourage low-density lipoprotein (LDL) cholesterol to stick to artery walls 心脏病
- certain cancers, triggered by damaged cell DNA. 癌症
Sources of antioxidants
Plant foods are rich sources of antioxidants. They are most abundant in fruits and vegetables, as well as other foods including nuts, wholegrains and some meats, poultry and fish.
Good sources of specific antioxidants include:
- allium sulphur compounds – leeks, onions and garlic
- anthocyanins – eggplant, grapes and berries
- beta-carotene – pumpkin, mangoes, apricots, carrots, spinach and parsley
- catechins – red wine and tea
- copper – seafood, lean meat, milk and nuts
- cryptoxanthins – red capsicum, pumpkin and mangoes
- flavonoids – tea, green tea, citrus fruits, red wine, onion and apples
- indoles – cruciferous vegetables such as broccoli, cabbage and cauliflower
- isoflavonoids – soybeans, tofu, lentils, peas and milk
- lignans – sesame seeds, bran, whole grains and vegetables
- lutein – green, leafy vegetables like spinach, and corn
- lycopene – tomatoes, pink grapefruit and watermelon
- manganese – seafood, lean meat, milk and nuts
- polyphenols – thyme and oregano
- selenium – seafood, offal, lean meat and whole grains
- vitamin A – liver, sweet potatoes, carrots, milk, and egg yolks
- vitamin C – oranges, blackcurrants, kiwifruit, mangoes, broccoli, spinach, capsicum and strawberries
- vitamin E – vegetable oils (such as wheatgerm oil), avocados, nuts, seeds and whole grains
- zinc – seafood, lean meat, milk and nuts
- zoochemicals – red meat, offal and fish. Also derived from the plants that animals eat.