The Irish Times recently featured a book by Dr. Karl Herrup about “How Not to Study a Disease.” Dr. Herrup is clear that he opposes the theory that the amyloid cascade causes Alzheimer’s disease.
There is considerable debate on the subject at pharmaceutical corporations and academic institutions worldwide. In his book. Dr. Herrup suggests that researchers consider alternate theories. He advises caution when reviewing previous investigations.
The cascade hypothesis, which Professor Herrup questions, is the buildup of plaques within the brain. This buildup has been thought to be sufficient to understand Alzheimer’s.
A New Direction
Dr. Herrup, a neurobiology professor, is opposed to the traditional view. He believes that a new direction is in order. Dr. Herrup was interviewed by Dr. Conor Purcell, a contributor to the Irish Times.
Dr. Purcell questioned Dr. Herrup’s reason for writing the book. Dr. Herrup explained that he was a developmental biologist, which is defined as investigating an organism’s progression through life cycles.
However, the more he studied the current hypothesis, the more it made no sense to him. He became frustrated by the way in which the biological mechanisms were described by the rest of the field.
When asked “why now,” Dr. Herrup explained that it is not enough to be a non-supporter of the theory, but it is also necessary to provide a constructive path for the medical field to follow. He also wanted to include the general public, not just his colleagues, so a book seemed to be in order.
About the Amyloid Hypothesis
When the hypothesis was first created several decades ago, Dr. Herrup was impressed that it was a creative hypothesis. It stated that structural problems in the brain will create functional problems. If something was wrong with the structure of the brain it would explain certain symptoms.
It all began with a woman who had severe dementia. After the woman died, an autopsy was performed. Deposits or plaques were found that were thought to be the cause of her disease. They were considered to be associated with Alzheimer’s disease.
When asked now about the cause of the disease, Dr. Herrup replied that it is complicated. He does not completely dismiss the cascade hypothesis but he does think that alternative ideas are necessary.
For example, he explains that significant plaque in a person’s brain increases the risk of dementia in the next five years compared to a brain that was free of plaque. But he points out that if you look closely at the numbers, although as aforementioned they are significant, they are not substantial. Therefore, he continues, plaques are not the answer.
Dr. Herrup is joined by other doctors in citing inflammation, calcium homeostasis, and oxidation affecting the brain even without any plaque build-up.
Blood pressure that is controlled plus a good diet and exercise are given credit for preventing Alzheimer’s. Diabetes type II is mentioned in his book as a risk factor again relating to lifestyle choices.
Clinical trials investigating lifestyles linked to disease are ongoing. While the public is exploring these considerations, Dr. Herrup and colleagues are hoping to unravel the cause of Alzheimer’s.
