Researchers Rafael Jiménez, Carmen Cabrera and Reyes Artacho, of the Department of Nutrition of the Universidad de Granada, compiled in an article the most recent studies –especially epidemiological– evaluating the relationship between the consumption of green tea and its influence on human health. A total number of 180 works published in the best international journals. This wide bibliographic review has just been published in the Journal of the American College of Nutrition, under the title “Beneficial effects of green tea”.
After water, tea is the most consumed drink in the world. Green tea is one of its varieties, a thousand-year-old beverage highly appreciated in other parts of the world, which is believed to have healthy properties such as the risk reduction of cardiovascular diseases and some forms of cancer, body weight control, antibacterial and antiviral activity, antidiarrhoea properties, and protection against solar ultraviolet radiation. It has also been proven useful in oral health (prevention of tooth decay and periodontal disease) and cosmetics.
Antioxidant properties
“The idea of designing this review comes from a research project on the presence of tea components with antioxidant activity”, explain the authors. In this matter the scientists have focused their bibliographic work in green tea because it is not affected by the so-called “fermentation” process that affects black tea. That is why catechins (which arephenolic compounds) retain all their antioxidant activities, which has been demonstrated via in vitro or in vivo studies. Important in these catechins is their high content in EGCG (epigallocatechin-3-gallate), which “biologically is the most active one”. Green tea also contains minerals and other compounds that further increase the antioxidant activity. On the other hand, the researchers point to its caffeine content, which is lower than in black tea and other stimulants, and describe green tea as a natural, refreshing, pleasant and accessible beverage which is “an alternative to less healthy drinks”.
Most of these effects have recently been endorsed by scientific studies, especially all the properties related to their antioxidant activity. However, according to the researchers, some authors differ on the matter of the ideal consumption of green tea for the effects to take place. Also, they add that “the consumption of green tea must be combined with a healthy lifestyle”.
All the evidence presented in reviewed and discussed studies leads scientists from Granada to consider that regular consumption of green tea can augment the total intake of antioxidants and therefore be positive for health. They also ensure that “loose green-tea leaves are better than tea bags”.
Reference
Prof. Carmen Cabrera Vique
Department of Nutrition
Tel. +34 958 240 669 / +34 958 243 863. Email. carmenc@ugr.es
