Build-up of urea in the brain to toxic levels can cause brain damage—and eventually dementia, according to an international team of scientists led by professor Garth Cooper from the University of Manchester.
In a paper published yesterday in the Proceedings of the National Academy of Sciences, the team showed that Huntington's disease—one of seven major types of age-related dementia —is directly linked to brain urea levels and metabolic processes. The study also showed that the high urea levels occurred before dementia set in, which could help doctors to one day diagnose and even treat dementia, well in advance of its onset.
"This study on Huntington's Disease is the final piece of the jigsaw which leads us to conclude that high brain urea plays a pivotal role in dementia,” explained Professor Cooper, whose previous work identified metabolic linkages between Huntington's, other neurodegenerative diseases, and type-2 diabetes.
"Alzheimer's and Huntington's are at opposite ends of the dementia spectrum—so if this holds true for these types, then I believe it is highly likely it will hold true for all the major age-related dementias,” he added.
"More research, however, is needed to discover the source of the elevated urea in HD, particularly concerning the potential involvement of ammonia and a systemic metabolic defect.”
The team used human brains, donated by families for medical research, as well as transgenic sheep in Australia. Gas chromatography/mass spectrometry was used to measure brain urea levels.