Green Tea

Green Tea Keeps Elders Mentally Sharp: Research Showing Multiple Ways

Green tea helps slow the age-related decline in brain function seen as declining memory, cognitive impairment, dementia and Alzheimer's, shows a human study published in the February 2006 issue of the American Journal of Clinical Nutrition.

Researchers at Japan's Tohoku University studied 1003 subjects over age 70, comparing their green tea intake and mental sharpness, using a Mini-Mental State Examination, a well-accepted standardized test for measuring cognitive function.

Drinking more than 2 cups a day of green tea slashed odds of cognitive impairment in elderly Japanese men and women by 64%! And a Japanese cup of green tea is much smaller than its American counterpart-only about 3.2 fluid ounces.

And at every level of cognitive impairment-from minimal to severe-those drinking the most green tea experienced significantly less mental decline than those drinking the least:

Compared with elderly Japanese who drank less than 3 cups a week, those drinking more than 2 cups a day had a 54% lower risk of age-related declines in memory, orientation, ability to follow commands and attention. Those drinking 4 to 6 cups of green tea a week (1 cup a day) had a 38 lower risk of declines in brain function.

Green tea's primary protective agent is thought to be its catechin phytonutrient epigallocatechingallate or EGCG.

Research shows this highly potent antioxidant:

  • Helps prevent the formation of B-amyloid, a protein whose accumulation is recognized as causing Alzheimer's (Basianetto S, Eur J Neurosci Jan 2006).
  • Protects brain cells by chelating (removing) iron, which might otherwise produce destructive free radicals (Reznichenko L, J Neurochem, March 2006).
  • Helps prevent oxidative stress-induced brain cell death by "talking" to brain cells' genes responsible for cell cycling and survival. Specifically, EGCG tells the genes in neurons to decrease production of caspase 3, an enzyme involved in initiating programmed cell death. (Park HJ, Life Sci Jan 2006; Levites Y. J Biol Chem, 2002)
  • Promotes memory-related learning ability by protecting cells in the hippocampus, a part of the brain involved in spatial cognition and memory-related learning ability, from free radical damage (Haque AM, J Nutr April 2006).