Study on mice: green tea could help reduce Alzheimer's-like symptoms

A diet containing compounds found in green tea and carrots has been successful in reversing Alzheimer's symptoms in mice. Although studies on mice do not always translate to humans, this discovery opens the door to herbal treatments that may offer protection against dementia in humans, researchers said. University of Southern California.

The study also supports the idea that a combination of treatments rather than a quick fix might be the best way to treat Alzheimer's disease. Combination therapy is already the standard treatment for diseases such as cancer, HIV infection and rheumatoid arthritis.

"It is not necessary to wait 10 to 12 years for a synthetic drug to market it; you can make these dietary changes today, "said Professor Terrence Town, lead author. "I find that very encouraging."

The team genetically programmed 32 mice to develop symptoms similar to Alzheimer's disease and randomly divided them into four groups each containing an equal number of healthy mice. Over the next three months, they fed mice on the epigallocatechin-3-gallate diet, or EGCG, a key ingredient in green tea, ferulic acid or AF, present in carrots and tomatoes, a combination of both, or placebo.

Before and after the diet, they put the mice to the test in a series of neuropsychological tests similar to the thought and memory tests used to evaluate dementia in humans. A Y-shaped labyrinth designed to test the mouse's spatial work memory, a skill that humans use to find a way out of a building, was one of those tools. Healthy mice instinctively explore each arm of the Y maze, looking for food or a way to escape and entering all three arms in order.

Before the special diet, mice genetically programmed to exhibit Alzheimer-type symptoms had difficulty performing this task. But after the diet, they were able to perform as well as their mentally healthy counterparts.

"After three months, the treatment of the badociation has completely restored the working memory," said Professor Town.

The results appear to be due to the ability of EGCG and FA to prevent large proteins in the brains of mice from breaking down into smaller substances called β-amyloid plaques. These smaller proteins then agglutinate and interrupt the activity of neurons in people with Alzheimer's disease. EGCG and AF also appeared to reduce brain inflammation – another essential feature of Alzheimer's disease in humans.

The team is now planning to look for other dietary sources of substances inhibiting the production of sticky beta-amyloid plaques.

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