Search This Blog

Tuesday, November 2, 2010

Tea Protects Cognitive Health and Bone Mineral Density

True tea – whether black, oolong, green or white – comes from the Camellia sinensis plant. White tea comes from young leaves that are steamed immediately after harvest. Green tea has undergone minimal fermentation. Oolong tea is partially fermented and black tea is fully fermented.

All varieties contain powerful antioxidants. One in particular, a catechin called epigallocatechin gallate-3 or EGCG, has been shown to fight cancer by inhibiting angiogenesis (the growth of new blood vessels to feed tumors) and inducing apoptosis (cancer cell death).  EGCG also reduces inflammation and activates enzymes in the liver that detoxify toxic compounds to facilitate their removal from the body. White and green teas contain the highest concentration of EGCG.

Studies have shown that regular consumption of black and oolong teas is associated with protection against cardiovascular disease. Research published in the American Journal of Clinical Nutrition highlight two more health benefits: protection against cognitive decline in older adults and preservation of bone mineral density in older women.

A study in Singapore examined the relationship between tea consumption and cognitive decline in more than 2500 Chinese men and women 55 years of age and older. Researchers measured tea intake and scores on Mini-Mental State Examination tests over a two year period. They found that regular consumption of black and oolong teas was associated with lower risk of mental impairment and cognitive decline. No correlation was found between coffee intake and cognitive status.

In the other study, researchers in Australia followed 1500 women aged 70 to 85 years for five years to study bone mineral density (BMD). A cross-sectional analysis of more than 1000 participants compared tea intake with BMD. After 4 years, the tea drinkers had lost significantly less mineral density in hip bones compared to non-tea drinkers. Researchers concluded that drinking tea is associated with preservation of BMD in older women.

References:

Tze-Pin Ng et al. Tea consumption and cognitive impairment and decline in older Chinese adults. American Journal of Clinical Nutrition, 88(1):224-231, July 2008.

Devine A et al. Tea drinking is associated with benefits on bone density in older women. American Journal of Clinical Nutrition, 86(4):1243-47, October 2007.

1 comment:

patti said...

Your teacup's twin is at my house. It misses you and so do I. Great blog Dr. Cimperman!