23/03/06 - Study Suggests Green Tea Could Help Protect Against Dementia

Green tea is a rich source of catechins, compounds suggested to play a beneficial role in weight loss, cardiovascular and oral health, with some, namely epigallocatechin gallate (EGCG), now emerging as particularly powerful.

The new study, published in The American Journal of Clinical Nutrition (Vol. 83, pp. 355-361), analysed the consumption of six drinks (green, black and oolong tea, coffee, cola or juice, and 100 per cent vegetable juice) for 1003 Japanese subjects with an average age of 74.

Using the cut-offs, 85.3 per cent of people who drank less than three cups of green tea a week had some level of cognitive impairment.

Only 59.8 per cent of people who drank more than two cups a day had some level of cognitive impairment (39.2 per cent with slight impairment).

The researchers found that people who drank more than two cups of green tea per day had a 50 per cent lower chance of having cognitive impairment, compared to those who drank less than three cups a week.

“In contrast, a weak or null relation between consumption of black or oolong tea or coffee and cognitive impairment was observed.

“Green tea polyphenols, especially EGCG, might explain the observed association with improved cognitive function… Green tea contains 67.5 mg catechins per 100 mL, whereas black tea contains only 15.5 mg per 100 mL

EGCG is said to be brain permeable, and its protection of the brain is proposed to be due to mechanisms other than its antioxidant and iron-chelating properties.

The study does have limitations, with the authors noting: “Healthier and more active individuals might have more opportunities to consume green tea. Among the Japanese, green tea is often consumed as a social activity, and this in itself may contribute to maintaining higher cognitive function.”

Source : alzheimersupport