More Studies on Tea Health Benefits Backed
http://www.mb.com.ph/articles/283439/mo ... its-backed
By GABRIEL S. MABUTAS
October 21, 2010, 6:24pm
MANILA, Philippines – The Food and Nutrition Research Institute Thursday recommended further studies on the health benefits of tea amid conflicting research as to whether it could indeed reduce the risk of cardiovascular diseases and stroke, as well as reduce weight with its anti-oxidant properties which are helpful in cardiovascular health.
This, even as it admitted that tea is the main source of flavonoids in the diet, which is also present in apples, grapes, wines and cocoas. Most of the health benefits of tea are attributed to flavonoids.
All true teas, according to the institute, come from the same plant, Camellia sinensis, ranging from green, oolong, white, black, rooibos tea, red tea and herbal tea infusions.
“The main difference is in the way the tea leaves are processed but all tea brews are full of natural goodness and health benefits,” it added.
Citing the lecture delivered by Dr. Jan Rycroft in a seminar on the “Bioactive Components of Tea and their Health Benefits” FNRI noted that an average 200 milliliter (mL) cup of green tea contains 120 milligrams (mg) of flavonoids while an average 300 mL cup of black tea contains 130mg.
Rycroft, category nutritionist of Unilever, presented different studies on the relationships of tea and flavonoids to different nutritional and health factors, such as antioxidant properties which are helpful in cardiovascular health, weight management and mental performance.
A dietary antioxidant is a substance in foods that significantly decreases the adverse effects of reactive oxygen and nitrogen species on the normal physiological function in humans.
In an experiment presented by Dr. Rycroft regarding flavonoids as antioxidants, however, results showed that bioavailability is low and flavonoids are modified upon absorption without indications of reduced damage in vivo.
Flavonoids have no proof for protection against free radical damage in the cells.
This study was supported by the European Food Safety Authority (EFSA) Panel on Diabetic Products, Nutrition and Allergies in 2010, which reported that a cause and effect relationship has not been established between the consumption of tea and the protection of body cells and molecules such as DNA, proteins and lipids from oxidative damage.
“According to various studies on cardiovascular health though, tea, in general, is associated with reduced risk of cardiovascular diseases, specifically lowering the risk of myocardial infarction, stroke and ischemic heart disease,” the FNRI noted.
They claimed, it said, that consumption of two to three cups of black or green tea per day improves blood vessel function.
“Tea consumption can help in weight management program, according to a number of Asian studies that found a reduction of visceral fat after consumption of high catechin green tea for 12 weeks. It was also shown that high catechin green tea increases fat oxidation,” the FNRI said.
L-theanine, on the other hand, is an amino acid naturally exclusive from tea that is responsible for the production of alpha waves in the brain which has a calming effect on the body and gives the balance of deep relaxation and mental alertness, according to Dr. Edgardo Tolentino of the Makati Medical Center.
A typical 200mL serving of black tea contains 4.5 – 22.5mg of L-theanine.