Green Tea May Ease Mental Distress According To a New Study...
Drinking five cups of green tea per day may reduce the incidence of
psychological distress by 20 per cent, says a new study from Japan.
In a study with 42,093 Japanese individuals 2,774 people, or 6.6 per
cent of the study population, suffered from psychological stress, and
green tea consumption was said to improve psychological
More than 450 million people suffer from stress worldwide, with a
large percentage of people stating that stress is the most important
risk factor to health. The related costs of stress estimated at $200
billion in the US (International Labor Office).
Researchers from Tohoku University Graduate School of Medicine
report their findings in the American Journal of Clinical Nutrition.
Green tea and its extracts already have a positive reputation,
with studies reporting they may offer protective effects against
Alzheimer's and certain cancers, improve cardiovascular and
oral health, and play a positive role in weight management.
Despite reports already stating that green tea or its constituents
might reduce psychological stress, no large-scale study has
evaluated the relationship between green tea consumption and
psychological distress, said the researchers.
After adjusting their results for potential confounding factors,
including age, sex, history of disease, BMI, alcohol consumption,
cigarette smoking, diet, and other factors, a significant inverse
association between green tea consumption and psychological
distress was observed for people who drank at least five cups of
green tea per day, compared to those who drank less than one
cup per day.
The four primary polyphenols found in fresh tea leaves are
epigallocatechin gallate (EGCG), epigallocatechin (EGC),
epicatechin gallate (ECG), and epicatechin (EC).
A earlier Japanese study reported that green tea extracts may
offset the signs of physical and mental fatigue associated with
modern stressful lives. Five days of supplementation with EGCG
was found to reduce levels of oxidised species related to fatigue
in an animal model, according to findings in previously published
Green tea is said to contain over four times the concentration of
antioxidant catechins than black tea (green tea leaves that have
been oxidized by fermentation), about 70 mg catechins per
100 mL compared to 15 mg per 100 mL for black tea.
Source: American Journal of Clinical Nutrition