Alzheimer’s disease research: are we heading in the wrong direction?
New scientific results suggest that the current wisdom regarding what causes Alzheimer’s disease is probably wrong. It is widely thought that a molecule called amyloid is responsible for the brain damage that occurs in Alzheimer’s disease. This idea is called the amyloid hypothesis, and huge efforts are being made to find ways to reduce the amount of this molecule in the brain. According to scientists, the less amyloid we have, the smaller the chance of getting the disease.
The pharmaceutical industry, from small start-up companies to huge multinational conglomerates, have placed all their chips on this idea for more than a decade now, and the results have been an unqualified disaster. They have been able to reduce the amounts of amyloid in the brain but, surprisingly, with no therapeutic benefits at all and, in some cases, with additional damage done to patients. In addition to that, new evidence keeps accumulating from molecular, cellular, animal and human studies that suggests that the amyloid hypothesis might indeed be wrong, and amyloid itself is likely to be a secondary player, that is indeed present in the brain, but only as a response to the real bad guys that cause the disease.
So we have a long-term lack of success in clinical trials as well as scientific evidence from multiple sources showing that amyloid is not an early source of damage in the Alzheimer’s brain. Accordingly, the sensible thing to do would be to put amyloid-based clinical trials on hold and direct more resources towards trying to understand the mechanisms that lead to the disease.