The cholesterol found in the brain acts as a catalyst that triggers the formation of beta-amyloid plaques. A new study conducted by the University of Cambridge, in the United Kingdom, shows how cholesterol can also play an important role in the onset and progression of Alzheimer‘s.
According to the finding, the cholesterol found in the brain acts as a catalyst that triggers the formation of beta-amyloid plaques. These are proteins toxic to neurons, which are determinant in their deterioration and death -the so-called neurodegenerative process-, and which are known to be fundamental in the development of Alzheimer’s disease.
The link between beta-amyloid protein and Alzheimer’s has evidence to spare. But, until now, researchers did not know how this protein begins to aggregate in the brain since it is normally present at very low levels.
That is where the work of Michele Vendruscolo, together with colleagues from the University of Lund in Sweden, gives an answer. Through laboratory tests, the researchers observed that beta-amyloids bind completely naturally to lipids (cholesterol) -which are very “sticky”- of cell membranes.
As a result, proteins accumulate until they end up forming plaques so harmful to neurons.
In fact, the study showed that cholesterol accelerates the speed of aggregation of beta-amyloid proteins in the brain by more than 20 times, said Professor Vendruscolo.
“This work has helped us narrow down a specific question in the field of Alzheimer’s research, and now we need to understand in more detail how to find ways to not trigger the neurodegenerative process”, he said.
Although it does not enjoy a good reputation, cholesterol plays an essential role in the body. “There are cholesterols that are necessary since they are one of the components of the plasma membranes of all cells (including neurons)”, explained Dr. Evelyn Benavides, a neurologist at the University Clinic of the Andes.
But when it is found in high amounts, this cholesterol ends up being a problem, especially if it is the so-called bad cholesterol. “Total cholesterol is the sum of good cholesterol (HDL) and bad (LDL), the increase in LDL causes some inflammatory markers that may be related to neuronal death and the oxidation and phosphorylation process that occurs in the brain of patients in the early stages of Alzheimer’s”, added the neurologist.
Therefore, although not enough information is available, it is estimated that a diet rich in fish and low in saturated fats and refined sugars -such as the Mediterranean diet, for example- influences a decrease in the incidence of cerebral degenerative pathology.
On the contrary, the evidence shows that high levels of cholesterol throughout life increase the risk of cognitive deterioration and, even so, dementia.
Vendruscolo said yes, that “we are not saying that cholesterol is the only trigger of the aggregation process that gives rise to the plates, but there is no doubt that it is one of those responsible”. Therefore, “the question is not how to eliminate cholesterol from the brain, but how to control the role it plays in Alzheimer’s by regulating its interaction with beta-amyloid protein”, he claimed.
In his opinion, these results show a new way to develop useful measures for the prevention and treatment of the disease, which is estimated to affect more than 46 million people on the planet. In fact, as they explained in the journal “Nature Chemistry”, the authors believe that it is possible to design drugs capable of maintaining homeostasis of cholesterol and therefore of beta-amyloid proteins, in the brain.
Until then, added Dr. Benavides, it is necessary to continue resorting to factors that have shown some decrease in the incidence of Alzheimer’s, such as achieving an adequate weight throughout life; control cardiovascular risk factors such as hypertension, hypercholesterolemia, and diabetes. It is also essential to keep the brain active (through reading, work, sports, or cultural activities), avoid smoking, and excessive consumption of alcohol.
