Several studies have linked green tea consumption with a reduced risk of developing Alzheimer’s disease, but the mechanisms behind this link were unclear. Now, research led by the department of chemistry and chemical biology at McMaster University (Canada) reveals how: through a green tea compound that alters the formation of toxic plaques that contribute to the disease.
Alzheimer’s disease, a progressive neurodegenerative disease characterized by a decline in memory and general cognitive functioning, affects nearly 50 million people worldwide and estimates that by 2050 there could be more than 130 million people.
The exact causes of this disease are unclear, but beta-amyloid is believed to play a major role, as this sticky protein can clump together, forming plaques that disrupt communication between neurons.
The researchers found that epigallocatechin gallate (EGCG), a green tea polyphenol, stops the formation of beta-amyloid plaques, a hallmark of Alzheimer’s disease, by interfering with the function of oligomers (proteins composed of more than a polypeptide chain) beta-amyloid.
The power of EGCG
The study, published in the Journal of the American Chemical Society, sheds light on how EGCG might help prevent the formation of beta-amyloid plaques by approaching the much-needed prevention strategies for Alzheimer’s disease.
The researchers came to their conclusions by using nuclear magnetic resonance to gain insight into how this green tea polyphenol (EGCG) could affect the formation of beta-amyloid plaques. Scientists discovered that EGCG “remodels” beta-amyloid oligomers – which can bind and form beta-amyloid-toxic plaques – which prevents them from creating these harmful plaques.
“At the molecular level, we believe EGCG covers toxic oligomers and changes their ability to grow and interact with healthy cells,” explains Giuseppe Melacini, the leader of the work.
These findings not only support previous studies suggesting that polyphenol EGCG may help prevent beta-amyloid plaque formation, but also shed light on the mechanisms underlying this association.
Based on their findings, the researchers suggest that green tea extracts could be used in the prevention of Alzheimer’s disease:
“We all know that there is currently no cure for Alzheimer’s disease once the symptoms appear, so our best hope is early intervention. That could mean using extracts of green tea or its derivatives from the beginning; say 15 to 25 years before symptoms appear, “says Melacini.
The authors note, however, that it is difficult to administer EGCG polyphenol directly to the brain, so future research should focus on finding ways to modify this compound and overcome this problem. Be that as it may, it is great news.