A team of scientists from all over the world recently confirmed the discovery of a major cause of dementia, a disease associated with a decline in memory and losing the ability to perform everyday activities. Unfortunately, a cure for dementia hasn’t been discovered yet, but this could lead to possible treatments and diagnosis.
Garth Cooper, a professor from the University of Manchester and leader of the Manchester team, unravels the cause behind dementia.
He claims that toxic amounts of urea in the brain can cause brain damage and eventually dementia.
The international team consists of scientists coming from many different universities such as The University of Manchester, the University of Auckland, Ag Research New Zealand, the South Australian Research and Development Institute, Massachusetts General Hospital and Harvard University.
Huntington’s Disease is one of the seven major types of age-related dementia. It was proven that this disease is directly connected with levels of urea in the brain and metabolic processes.
The scientists’ 2016 study, published in the Proceedings of the National Academy of Sciences, reveals that urea is similarly linked to Alzheimer’s. According to Professor Cooper this newly discovered information could be relevant to all types of dementias related with age, which could help doctors to diagnose and even treat the disease one day, well in advance of its onset.
Urea is more commonly known as the compound excreted from our body through urine, but it could be also found in the brain as a metabolic breakdown product of protein, together with ammonia. If these two build up in the body the kidneys can’t eliminate them.
“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. 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”, says professor Cooper, from The University of Manchester’s Division of Cardiovascular Sciences.
According to him, more research is needed in order to discover the source of the elevated urea in HD, particularly concerning the involvement of ammonia and a systemic metabolic defect.
“This could have profound implications for our fundamental understanding of the molecular basis of dementia, and its treatability, including the potential use of therapies already in use for disorders with systemic urea phenotypes.”
For the needs of their research, the team used human brains donated for medical research in which they measured brain urea levels. For them to be toxic, they must rise 4-fold or higher than in the normal brain.
“We already know Huntington’s Disease is an illness caused by a faulty gene in our DNA – but until now we didn’t understand how that causes brain damage – so we feel this is an important milestone. Doctors already use medicines to tackle high levels of ammonia in other parts of the body. Lactulose – a commonly used laxative, for example, traps ammonia in the gut. So it is conceivable that one day, a commonly used drug may be able to stop dementia from progressing. It might even be shown that treating this metabolic state in the brain may help in the regeneration of tissue, thus giving a tantalizing hint that reversal of dementia may one day be possible”, concludes professor Copper.