Monday Dec 1, 2008 (foodconsumer.org) -- A new study published in 2008 in Nutrition suggests that daily intake of green tea (Camellia sinensis) extracts may lower blood pressure, cholesterol and biomarkers of oxidative stress.

The randomized, double-blind, placebo-controlled study showed taking green tea extract supplements for three weeks lowered systolic and diastolic blood pressures by 5 and 4 mmHg respectively and reduced total cholesterol by 10 mg/dL.

Previous studies have already suggested that intake of green tea and its extracts may reduce risk of a variety of diseases including cardiovascular disease, Alzheimer’s disease and some cancers.

Green tea contains highest amounts of water-extractable polyphenols than black tea, 30-40 percent versus 3- 10 percent, according to nutraingredients.com. Epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC) are the four major polyphenols found in fresh tea leaves.

The study was conducted by Meri Nantz and colleagues from the University of Florida, Brigham and Women’s Hospital and Harvard Medical School, and the Nutritional Science Research Institute in Boston.

For the three-week study, 52 healthy men and 72 healthy women ages 29 on average were assigned Cardio Guarda green tea extract Suntheanine at a dose with 100 mg of L-theanine prepared by Taiyo International and 200 mg of a decaffeinated catechin green tea extract Sunphenon 90DCF by the same company.

At the end of the study, total and low density lipoprotein cholesterol levels dropped 10 and 9 mg/dL respectively.   Malondialdehyde indicative of oxidative stress and amyloid-alpha, a marker of chronic inflammation were also reduced by 12 and 42 percent respectively.