Bioflavonoids, or just flavonoids, are a group of water-soluble plant pigments that are responsible for the colors of many flowers and fruits. Flavonoids are found in a wide range of foods and supplementation is usually not required by individuals eating a healthy diet.
Bioflavonoids are often called “semi-essential” nutrients because they are an important part of our regular nutritional needs and support health as anti-inflammatory, antihistaminic and antiviral agents. They possess antioxidant properties that help fight poor health and aging. Flavonoids are referred to as “biological response modifiers” because they help to modify the body’s reaction to allergens, viruses and carcinogens. The flavonoids help protect vitamin C, and citrus flavonoids in particular improve the absorption of vitamin C.
Flavonoids can be divided into categories, but how to divide them is not universally agreed upon. One system breaks them into isoflavones, anthocyanidins, flavans, flavonols, flavones and flavanones. Some of the best-known flavonoids, such as genistein in soy and quercetin in onions, could be considered subcategories. Other flavonoids include catechin, hesperidin, rutin and naringin. Although they are all structurally related, their functions are different.
When doctors recommend supplementation, the most common amounts suggested are 1,000mg of citrus flavonoids or 400mg of quercetin, each taken three times per day. No side-effects have been linked to the flavonoids except for catechin, which can occasionally cause reversible fever, hives and anemia from the breakdown of red blood cells.
Conditions that suggest Bioflavonoid Need
Bruising Susceptibility
A double-blind study of 96 people with fragile capillaries found that bioflavonoids decreased the tendency to bruise [Int Angiol. 1993;12: pp.69-72]. In a single-blind study of 27 wrestlers, 71% of those taking a placebo were injured, with bruises making up more than half their injuries; in contrast, only 38% of those taking the supplement were injured, none of whom sustained bruises. In a follow-up double-blind study of 40 football players, the treated group received fewer severe bruises than the group taking placebo [Med Times. 1960;88: pp.313-316].
Key
 | Strong or generally accepted link |
Glossary
Anti-inflammatory
Reducing inflammation by acting on body mechanisms, without directly acting on the cause of inflammation, e.g., glucocorticoids, aspirin.
Antioxidant
A chemical compound that slows or prevents oxygen from reacting with other compounds. Some antioxidants have been shown to have cancer-protecting potential because they neutralize free radicals. Examples include vitamins C and E, alpha lipoic acid, beta carotene, the minerals selenium, zinc, and germanium, superoxide dismutase (SOD), coenzyme Q10, catalase, and some amino acids, like cystiene. Other nutrient sources include grape seed extract, curcumin, gingko, green tea, olive leaf, policosanol and pycnogenol.
Allergen
A substance that is capable of producing an allergic response in the body.
Virus
Any of a vast group of minute structures composed of a protein coat and a core of DNA and/or RNA that reproduces in the cells of the infected host. Capable of infecting all animals and plants, causing devastating disease in immunocompromised individuals. Viruses are not affected by antibiotics, and are completely dependent upon the cells of the infected host for the ability to reproduce.
Vitamin C
Also known as ascorbic acid, Vitamin C is a water-soluble antioxidant vitamin essential to the body's health. When bound to other nutrients, for example calcium, it would be referred to as "calcium ascorbate". As an antioxidant, it inhibits the formation of nitrosamines (a suspected carcinogen). Vitamin C is important for maintenance of bones, teeth, collagen and blood vessels (capillaries), enhances iron absorption and red blood cell formation, helps in the utilization of carbohydrates and synthesis of fats and proteins, aids in fighting bacterial infections, and interacts with other nutrients. It is present in citrus fruits, tomatoes, berries, potatoes and fresh, green leafy vegetables.
Milligram
(mg): 1/1,000 of a gram by weight.
Urticaria
Commonly known as hives, urticaria is one of the most common dermatological conditions seen by allergists. Urticaria is not just an allergic disease, however. It can be caused by metabolic diseases, medications, infectious diseases, autoimmune disease, or physical sensitivity. Traditional allergies to foods or medications as well as viral illness are frequent causes of acute urticaria which usually lasts only a few hours but may last up to 6 weeks. Chronic urticaria (lasting more than 6 weeks) is more complex, given the vast number of potential triggers. Symptoms include sudden onset; initial itching; then swelling of the surface of the skin into red or skin-colored welts (wheals) with clearly defined edges; welts turn white on touching; new welts develop when the skin is scratched; usually disappear within minutes or hours. Welts enlarge, change shape, spread or join together to form large flat raised areas.
Anemia
A condition resulting from an unusually low number of red blood cells or too little hemoglobin in the red blood cells. The most common type is iron-deficiency anemia in which the red blood cells are reduced in size and number, and hemoglobin levels are low. Clinical symptoms include shortness of breath, lethargy and heart palpitations.
Red Blood Cell
Any of the hemoglobin-containing cells that carry oxygen to the tissues and are responsible for the red color of blood.
Bruise
Injury producing a hematoma or diffuse extravasation of blood without breaking the skin.
Placebo
A pharmacologically inactive substance. Often used to compare clinical responses against the effects of pharmacologically active substances in experiments.
