Green Tea Again Linked to Alzheimer's Prevention and Treatment
That green tea you’ve been drinking may just protect[1] your brain. In yet another major study on the beverage’s healthful properties, this time published in the journal Phytomedicine, scientists found evidence that enzymes in the drink protect your brain cells from damage. The findings suggest that drinking green tea regularly could prevent you from developing dementia and Alzheimer’s Disease later in life. Past studies had suggested that certain compounds in undigested tea could slow or prevent cancer as well.
The study[2] was conducted by researchers at Newcastle University and revolved around polyphenols, compounds found in both green and black tea. The Newcastle team focused on whether or not once the tea was in the digestive system if the protective properties were still as effective. It was unknown whether the chemical reactions that take place during digestion altered the polyphenols to the point that they were no longer effective at slowing cancer or brain deterioration.
The Newcastle team found that unlike many compounds that become ineffective once the digestive process begins, the polyphenols in tea appear to retain their protective powers. This sounds like good news. But the Alzheimer’s Society has gone on the record[3] to advise people to remain only cautiously optimistic about the benefits of green tea against the disease. They have pointed out that the researchers used higher concentrations of the main compound, CAGTE, than would be found in the system of even a dedicated tea-drinker.
Past research on the subject includes a study[3] published in 2005 that also looked at the properties of green tea in combating Alzheimer’s. Conducted by the University of South Florida and published in the Journal of Neuroscience, the trials looked at the protective properties of a different component, called EGCG, an antioxidant that has been the focus of continued anti-cancer studies. In their research, EGCG acted as a protein blocker, preventing the chemical reactions that most often lead to the nerve damage and memory loss that are hallmarks of Alzheimer’s Disease.
Like the more recent Newcastle study, there are some caveats to the green-tea-as-wonder-drug hype, however. The Florida researchers found that flavonoids, another compound found in green tea, counteracts EGCG, rendering it essentially ineffective. The lab mice given EGCG were given injections of the compound itself, not given green tea. Therefore, in order for EGCG to be proven as a treatment both for reducing Alzheimer’s plaque in the brain and preventing its buildup in the first place, further studies need to be conducted using only pure EGCG.
The Alzheimer’s Society admits that both previous and current studies have indicated that properties in green tea may help prevent the disease, but caution that the process involved is poorly understood. They are calling for further studies into the various compounds that are showing promise. Until then, they advise a healthy diet and exercise approach rather than drinking gallons of green tea to help prevent dementia and Alzheimer’s.
