USC researchers are studying plant-based substances that inhibit the production of the sticky amyloid beta plaques known to build up as a part of Alzheimer’s disease. The study involved mice who were genetically programmed to develop Alzheimer’s. They were fed a diet containing compounds found in green tea and carrots. It reversed Alzheimer’s-like symptoms in the animals. The research was published in the Journal of Biological Chemistry.
The findings lend credence to the idea that certain readily available, plant-based supplements might offer protection against dementia in humans. However, the researchers do emphasize that the study was in mice and many mouse discoveries never translate into human treatments because humans and mice are very different.
Terrence Town, a professor of physiology and neuroscience at the Keck School of Medicine of the University of Southern California’s Zilkha Neurogenetic Institute, and senior author of the study said:
“You don’t have to wait 10 to 12 years for a designer drug to make it to market; you can make these dietary changes today. I find that very encouraging.”
5.7 million Americans are currently living with Alzheimer’s. This study also supports the idea that combination therapy, rather than a single magic bullet, may offer the best approach to treat them all. Combination treatment works well and it is already the standard of care for diseases such as cancer, HIV infection and rheumatoid arthritis.
The Study
- The researchers took a look at two compounds, EGCG, or epigallocatechin-3-gallate, a key ingredient in green tea, and FA, or ferulic acid, which is found in carrots, tomatoes, rice, wheat and oats.
- 32 mice with Alzheimer’s-like symptoms were randomly assigned to one of four groups with an equal number of males and females.
- Each group also included an equal number of healthy mice, for comparison.
- The mice consumed a combination of either EGCG and FA, or EGCG or FA only, or a placebo. They did this for 3 months.
- The dosage was 30 milligrams per kilogram of body weight. Such a dosage is well-tolerated by humans and can easily be consumed as part of a healthy diet.
The Results
Scientists ran the mice through a battery of neuropsychological tests that are roughly analogous to the thinking and memory tests that assess dementia in humans. All the mice did the tests before and after the three-month special diet.
An example of one of the tests was a maze in the shape of a Y, which tests a mouse’s spatial working memory. It is a skill that humans use to find their way out of a building. Mentally healthy mice instinctively explore each arm of the Y maze. They look for food or a route to escape and enter the three arms in sequence more often than by chance alone. Impaired mice can’t do this as well.
Town said:
“After three months, combination treatment completely restored spatial working memory and the Alzheimer’s mice performed just as well as the healthy comparison mice.”
How The Substances Work
Town says “one mechanism appeared to be the substances’ ability to prevent amyloid precursor proteins from breaking up into the smaller proteins called amyloid beta that gum up Alzheimer patients’ brains. In addition, the compounds appeared to reduce neuroinflammation and oxidative stress in the brain—key aspects of Alzheimer’s pathology in humans.”
What Next?
Town and his team will continue exploring combination treatment, with a focus on plant-derived substances that inhibit the production of the sticky amyloid beta plaques.
