ISSN: 1300-0292
İndekslendiği Dizinler: SCIENCE CITATION INDEX EXPANDED
CINAHL, Index Copernicus,
Chemical Abstracts (CA),
Excerpta Medica / EMBASE
Dil: Türkçe, İngilizce
İçerik: Orijinal Araştırma, Derleme, Editöre Mektup, Olgu Sunumu, Tıp Eğitimi, Tıbbi Kitap İncelemeleri
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Tea (camellia Sinensis); Composition, The Preventive Effects On Health And Consumption: Review
Dr. Fatma ÇELİKa
aBeslenme ve Diyetetik Bölümü, Dicle Üniversitesi Hastanesi, DİYARBAKIR
The beverage tea, derived from the top leaves of the plant Camellia sinensis is one of the most widely used beverages in the world, second only to water. The three main categories of tea- green, black and oolong- are the result of different processing procedures. Green tea and black tea have similar protective effects in most of the tests run. In recent years, tea has attracted more attention because of reported health benefits. Tea contains more than 4000 chemical compounds that may affect the human body in many aspects. It is generally believed that polyphenols such as theaflavins and thearubigins as well as catechins as majör constituents of tea are mainly responsible for antioxidant actions. Studies showed that tea possessed diverse pharmacological properties, which include anti-oxidative, anti-inflammatory, anti-mutagenic, anti-carcinogenic, anti-angiogenic, apoptotic, anti-obesity, hypocholesterolemic, anti-arteriosclerotic, anti-diabetic, anti-bacterial, anti-viral, anti-aging effects. However, these responses cannot always be reflected in human studies. This may be due to the limited bioavailability of tea components and the use of physiologically unachievable tea concentrations in some of the animal and in-vitro experiments. Caffeine in beverages such as tea and coffee is known to be toxic at high concentrations. Epidemiologic data and laboratory approaches indicate that the amount of polyphenols in four cups of tea or less (about 600 mL of a 1.5% solution) is insufficient to provide significant preventive effects in chronic diseases. Intake of 6-10 cups (approximately 960-1600 mL) of tea per day was shown to constitute a useful dietary habit to assist in lowering the risk of a number of chronic diseases. Total fluid intake in adults should be about 2.5 l; tea should account for 0.9-1.4 l of this amount.Keywords: Tea, polyphenols, catechin, antioxidantsTurkiye Klinikleri J Med Sci 2006, 26:642-648
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