Abnormal build-up of fat in brain can trigger Alzheimer's

Abnormal fat deposits in the brain could be a trigger for Alzheimer's disease, researchers have found for the first time.
Researchers affiliated with the University of Montreal Hospital Research Centre (CRCHUM) have discovered accumulations of fat droplets in the brain of patients who died from the disease and have identified the nature of the fat.
The breakthrough opens up a new avenue in the search for a medication to cure or slow the progression of Alzheimer's disease.
"We found fatty acid deposits in the brain of patients who died from the disease and in mice that were genetically modified to develop Alzheimer's disease," said Karl Fernandes, a researcher at the CRCHUM and a professor at the University of Montreal.

"Our experiments suggest that these abnormal fat deposits could be a trigger for the disease," said Fernandes.
The study highlights what might prove to be a missing link in the field of Alzheimer's disease.

Researchers initially tried to understand why the brain's stem cells, which normally help repair brain damage, are unresponsive in Alzheimer's disease.
They found that fat droplets near the stem cells, on the inner surface of the brain in mice were predisposed to develop the disease.
"We realised 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 University of Montreal.

"But this observation was dismissed and largely forgotten due to the complexity of lipid biochemistry," said Hamilton.
The researchers examined the brains of nine patients who died from Alzheimer's disease and found significantly more fat droplets compared with five healthy brains.
A team of chemists from University of Montreal led by Pierre Chaurand then used an advanced mass spectrometry technique to identify these fat deposits as triglycerides enriched with specific fatty acids, which can also be found in animal fats and vegetable oils.
"We discovered that these fatty acids are produced by the brain, that they build up slowly with normal ageing, but that the process is accelerated significantly in the presence of genes that predispose to Alzheimer's disease," said Fernandes.

"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," he said.
"Therefore, we think that the build-up of fatty acids is not a consequence but rather a cause or accelerator of the disease," he added.
There are pharmacological inhibitors of the enzyme that produces these fatty acids. These molecules, which are currently being tested for metabolic diseases such as obesity, could be effective in treating Alzheimer's disease, researchers said.
The study was published in the journal Cell Stem Cell.