Does Alzheimer's Disease Start in the Liver?

Study points to liver, not brain, as origin of Alzheimer's plaques

In the study, the scientists used a mouse model for Alzheimer's disease to identify genes that influence the amount of amyloid that accumulates in the brain. They found three genes that protected mice from brain amyloid accumulation and deposition. For each gene, lower expression in the liver protected the mouse brain. One of the genes encodes presenilin—a cell membrane protein believed to contribute to the development of human Alzheimer's...

...This finding suggested that significant concentrations of beta amyloid might originate in the liver, circulate in the blood, and enter the brain. If true, blocking production of beta amyloid in the liver should protect the brain.

To test this hypothesis, Sutcliffe's team set up an in vivo experiment using wild-type mice since they would most closely replicate the natural beta amyloid-producing environment. "We reasoned that if brain amyloid was being born in the liver and transported to the brain by the blood, then that should be the case in all mice," Sutcliffe said, "and one would predict in humans, too."

This is a big deal. If much of the amyloid that causes Alzheimer's plaques in man is also produced in the liver, it would be much easier to treat the liver to reduce the production of the amyloid than the brain.  The brain is protected by a pretty tight blood brain barrier that prevents many treatments from actually medicating the brain tissue itself.  Faster please.