Green tea has been used in Chinese medicine for hundreds of years and has recognized health benefits. A new study shows that one of those benefits may be protection against the development of Alzheimer’s disease and other types of dementia. Alzheimer’s disease is a disorder of the brain that can cause loss of memory and problems with behavior and thinking.
New research from the Newcastle University in England suggests that green tea may have the ability to protect the brain against Alzheimer’s and may also provide protection against cancer. A key component of the study was figuring out whether the components in tea that seemed to be effective when the tea was freshly brewed were also effective after the tea was digested.
Digestion is a critical process that allows the body to use the nutrients in foods that we eat. But Dr. Ed Okello, leader of the Newcastle research team, explained that just because a food is known to have certain benefits does not mean the benefits will be effective in the body after digestion because the necessary chemical compounds may be destroyed during the digestive process and may therefore not be absorbed into the body tissues.
Okello said, "What was really exciting about this study was that we found when green tea is digested by enzymes in the gut, the resulting chemicals are actually more effective against key triggers of Alzheimer's development than the undigested form of the tea."
In order to test digested green tea, the Newcastle team worked with Dr. Gordon McDougall of the Plant Products and Food Quality Group at the Scottish Crop Research Institute in Dundee. McDougall has developed technology that simulates the human digestive system which allowed researchers access to green tea after it had been through the process of digestion.
Scientists know that there are two toxic compounds that are active in the development of Alzheimer’s. Other compounds known as polyphenols are able to bind with the toxic chemicals to prevent them from damaging the cells in the brain. These polyphenols are present in both undigested black and green tea. But until the Newcastle study, scientists were not sure if the polyphenols survived the digestive process. Now they know that the polyphenols in green tea do survive and were able to prevent the toxic chemicals from destroying cells in the lab even after the tea was digested. The polyphenols were also effective in slowing down the growth of cancer cells in the lab.
The next step for the researchers is to test whether the benefits can actually be seen after the tea is digested in the human body. While this research may lead to ways to prevent Alzheimer’s disease in the future, Okello gave this reminder, "There are obviously many factors which together have an influence on diseases such as cancer and dementia -- a good diet, plenty of exercise and a healthy lifestyle are all important."
Sources:
Science Daily
Alzheimer’s Association