Vitamin C, also called ascorbic acid, is an essential vitamin you must consume as part of your food. It is crucial for many processes that help your body function normally and help you stay healthy. Vitamin C also has potent antioxidant activity that may help protect you from illness. Bioflavonoids are natural micronutrients found in many fruits and vegetables that have significant health benefits. Like vitamin C, they are powerful antioxidants that might help you avoid disease.
Vitamin C is a water-soluble compound that cannot be made by your body or stored in your tissues, so you must obtain a regular supply from food. You need it to help your tissues grow and to repair injuries, especially those occurring in collagen-containing tissues such as skin, cartilage, tendons, ligaments and blood vessels. Vitamin C is also a potent antioxidant, helping protect your body from potentially harmful free radicals. These molecules are byproducts of metabolism or the result of toxin breakdown. In the long term, they can damage cellular membranes, proteins and DNA, possibly hastening aging and raising your risk of heart disease, arthritis and cancer.
The Recommended Dietary Allowance for vitamin C differs slightly with age and sex, but in general, you should consume about 100 milligrams daily. Many fruits and vegetables are excellent sources, but one of the best is citrus fruits. One medium orange provides 70 milligrams of vitamin C and a 3/4-cup serving of orange juice contains more than 90 milligrams. Berries are also rich in vitamin C, with 1 cup of strawberries providing 85 milligrams. Among vegetables, red and green peppers are especially rich in vitamin C, providing 95 and 60 milligrams in 1/2 cup, respectively, while other vegetables such as broccoli, Brussels sprouts, spinach and green peas are also good sources. Since vitamin C is water soluble, consume fruits and vegetables raw or lightly steamed to get the most vitamin C from each serving.
Bioflavonoids, sometimes simply called flavonoids, are compounds made in plants that have beneficial biological activity in humans. Flavonoids are polyphenols that share a similar basic chemical structure. Some are pigments responsible for the bright colors of many fruits and vegetables. Flavonoids, which include resveratrol, proanthocyanidin, quercetin and catechin, may be at least partly responsible for the health benefits of a diet rich in fruits and vegetables. All of these compounds are powerful antioxidants that can destroy free radicals. According to the University of Maryland Medical Center, they also suppress tumor growth, help prevent inflammation and reduce the likelihood of blood clots. They may also boost the immune system, helping you avoid allergic reactions and infection, and they may prevent or reduce high blood pressure and lower your risk for certain cancers.
A single type of fruit or vegetable often contains several different bioflavonoids, but certain foods are especially rich in a particular compound. For example, red grapes, wine and olive oil are exceptionally rich sources of resveratrol, while apples and red, blue and purple berries contain abundant anthocyanidin. Catechins are found in green tea, apples and grapes, while quercetin-rich foods include citrus fruits, red onions, parsley, red apples consumed with their peels, apricots, dark cherries and darker types of berries. Although it is not known precisely how cooking affects the flavonoid content of food, some methods such as boiling may reduce the levels of certain compounds. For this reason, consume flavonoid-rich fruits and vegetables raw or steam them lightly whenever possible.
- University of Maryland Medical Center: Vitamin C (Ascorbic Acid)
- Linus Pauling Institute: Vitamin C
- University of Maryland Medical Center: Vitamins -- Phytochemicals
- Linus Pauling Institute: Flavonoids
- Office of Dietary Supplements: Vitamin C
- University of Maryland Medical Center: Quercetin
- Journal of Nutritional Science and Vitaminology: Various Cooking Methods and the Flavonoid Content of Onion
- fruit & vegetables 