Green Tea and Memory, What's the Connection?
You may be familiar with studies about the benefits of green tea for your heart, but a new study suggests reasons why it may also be good for your head. Scientists are giving a new meaning to "going green," proposing that green tea may have a positive impact on memory and learning.
Green tea offers memory boosters
Much of the excitement about green tea has involved the presence of epigallocatechin-3 gallate, better known as EGCG. This potent polyphenol (plant chemical with antioxidant properties) has been credited with having a positive impact on heart disease, as well as fight obesity and even protect the lungs of smokers.
The current study, reported in Molecular Nutrition & Food Research, involved two groups of mice, one of which was given EGCG while the other served as a control. Researchers set out to determine whether the antioxidant could improve cognitive function by enhancing the generation of brain cells (neurons), a process called neurogenesis.
To make that determination, the mice underwent three days of training to locate a visible platform in their maze. This was followed by seven days of training to find a platform that was hidden.
The study's authors discovered that the mice given EGCG were able to find the hidden platform faster than the control mice. This result indicated that EGCG has the ability to "increase the production of neural progenitor cells," according to one of the authors, Yun Bai, from the Third Military Medical University in Chongqing, China.
Neural progenitor cells are like stem cells, which means they have the ability to become different kinds of cells. Progenitor cells are more specific than stem cells, however, and differentiate into their target cells, which in this case was neurons.
The researchers concluded their findings showed that EGCG improved the animals' memory by helping them recognize the platform and improve their ability to remember information about their environment and orient themselves in it, also known as spatial memory.
In previous research, it's been proposed that green tea may help reduce the risk of Alzheimer's disease by interfering with the actions of acetylcholinesterase (AChE), an enzyme that breaks down acetylcholine. Levels of the brain neurotransmitter acetylcholine tend to decline with age, leading to short-term memory loss, but in people with Alzheimer's these levels can decrease by up to 90 percent.
The results of this latest study may offer individuals one more reason to consider green tea. Bai concluded that their finding "helps us to understand the potential for EGCG, and green tea which contains it, to help combat degenerative diseases and memory loss."
Kim HK et al. Effects of green tea polyphenol on cognitive and acetylcholinesterase activities. Bioscience, Biotechnology & Biochemistry 2004 Sep; 68(9): 1977-79
Wang Y et al. Green tea epigallocatechin-3-gallate (EGCG) promotes neural progenitor cell proliferation and sonic hedgehog pathway activation during adult pippocampal neurogenesis. Molecular Nutrition & Food Research 2012 Sept. doi:10.1002/mnfr.201200035