Could something as simple as drinking green tea protect you from developing Alzheimer’s? A host of new studies have looked at various aspects of how green tea affects the brain, and concluded yes.
Writing in the University of Michigan’s NeuroHealth blog last week, prominent neurologist Henry L. Paulson, MD describes the powerful properties of EGCG (official name: epigallocatechin-3-gallate), a flavonoid in green tea. EGCG, Paulson says, appears to protect the brain from the accumulation of amyloid plaques that scientists believe cause the brain deterioration associated with Alzheimer’s Disease. Paulson describes new research published in the Proceedings of the National Academy of Sciences by Chinese scientist Mi Hee Lim and her team that shows EGCG binds to beta-amyloid, the protein that forms into amyloid plaques, and changes it to prevent that from happening.
In a closely timed and related study published in the Journal of Biological Chemistry, A team of British researchers at the University of Leeds added green tea extract and resveratrol, an extract from red wine (See my recent reporting on resveratrol and weight loss here), to balls of amyloid protein and found that the bioflavonoids prevented the plaques from sticking to nerve cells. All of this research, and more, is described in the June 2013 issue of the Tufts University Health & Nutrition Letter, which appeared in my in-box recently. In a fascinating article titled Green Tea Protects Brain Cells, the editors describe four new studies showing that “green tea may someday be a potent weapon in the fight against Alzheimer’s disease and other forms of dementia.”
To my mind, the most interesting study of those described was published last August in the European Journal of Clinical Nutrition. Unlike most of the current crop of green tea studies, this one was done in humans, albeit just 12 of them. (And it was double blinded and placebo-controlled.) Most importantly, it’s the first study to use MRI technology to actually look at people’s brains to see the effect EGCG might have. Participants were given a beverage to drink after which they performed a memory-stimulating task while researchers monitored their brain function. Two different doses of green tea were tested against a placebo drink that contained no green tea. In those who had received green tea extract, the researchers observed increased activity in the dorsolateral prefontal cortex, which is an area of the brain responsible for processing working memory. They also noted a dose-response, meaning there was an even greater increase in brain activity at the higher dosage of green tea, which backs up the cause and effect relationship.
When it comes to green tea, there really isn’t much of a downside to argue about. No one has ever shown green tea to be harmful to health, and studies have also shown it to be protective against breast cancer and possibly other conditions such as Parkinson’s. I’m guessing the researchers who performed these studies are pouring themselves cups of green tea right now, and I’m about to do the same.
Forbes Magazine, 30.06.2013
http://www.forbes.com/sites/melaniehaiken/2013/06/30/green-tea-may-prevent-alzheimers-say-four-new-studies/