Researchers believe fatty deposits on the brain interfere with stem cells that are essential for memory, learning and repair of the organ. Photo by Miriam Doerr/Shutterstock
MONTREAL, Aug. 27 (UPI) -- Fatty acid deposits in the brain may contribute significantly to the development and progression of Alzheimer's disease, researchers discovered in a recent study.
The discovery supports the theory that Alzheimer's disease is a metabolic brain disease similar to obesity and diabetes being peripheral metabolic diseases. Researchers suggest treatments for obesity that are under development could prove useful against Alzheimer's disease as well.
"We discovered that these fatty acids are produced by the brain -- that they build up slowly with normal aging -- but that the process is accelerated significantly in the presence of genes that predispose to Alzheimer's disease," said Karl Fernandes, a professor at the University of Montreal, in a press release. "In mice predisposed to the disease, we showed that these fatty acids accumulate very early on, at two months of age, which corresponds to the early twenties in humans. Therefore, we think that the build-up of fatty acids is not a consequence but rather a cause or accelerator of the disease."
Researchers started by examining the brains of nine patients who died of Alzheimer's disease, finding significantly more fat droplets than in five healthy brains. This finding was in line with examinations of the brains of mice that had been genetically modified to be predisposed to developing Alzheimer's disease.
The fatty deposits appear to interfere with stem cells in the brain that repair damage. Using molecules that inhibit the enzymes that produce fatty acids, the researchers were able to prevent their building up in mice.
Although the researchers said they do not know the full effects of the molecules on the disease, they saw an increase in stem cell activity. This is important because stem cells play a significant role in memory, learning and and brain regeneration.
"We realized that Dr. Alois Alzheimer himself had noted the presence of lipid accumulations in patients' brains after their death when he first described the disease in 1906," said Laura Hamilton, a doctoral student at the University of Montreal Hospital Research Center. "But this observation was dismissed and largely forgotten due to the complexity of lipid biochemistry."
The study is published in Cell: Stem Cell.