As Alzheimer’s disease and related dementias reach epidemic proportions with no cure on the horizon, researchers, people living with the disease and their families are struggling to find an explanation for the lack of treatment options.
A new study suggests that it may be because Alzheimer’s is actually not one single disease but exists in three separate subtypes, which would mean separate treatment options tailored for each subtype. Learn more about the new study and the implications of dementia existing in three different forms.
Are There Subtypes of Dementia? A Rising Suspicion Among Researchers
It’s no secret that Alzheimer’s drug trials have been troubled. Last year, it was reported that over 99% of all potential drugs for the disease have failed over the last 10 years with only one medication available to alleviate some symptoms of the disease since 2004.
Most drug trials revolved around drugs targeting beta amyloid build up in the brain. In fact, more than 65% of all trials from 2002-2012 involved drugs targeting beta amyloid. More recently, drug developers have also been testing medications targeting another protein in the brain, tau, which is also a crucial protein in the development of dementia.
The unfortunate truth behind the high percentage of failed drugs and failed experimental studies lies the fact that researchers do not know exactly what causes Alzheimer’s. Dr. Dale Bredesen, professor of neurology at the University of California, Los Angeles believes this may be because there are subtypes to Alzheimer’s stating:
“Because the presentation varies from person to person, there has been suspicion for years that Alzheimer’s represents more than one illness.”
Bredesen, who is also the founding president of the Buck Institute for Research on Aging, recently conducted a study suggesting that Alzheimer’s is actually not one single disease, but instead exists in three different subtypes that he calls inflammatory, noninflammatory and cortical.
Study Suggests Three Different Subtypes of Alzheimer’s
Bredesen and his team performed regular metabolic testing on 50 people living with Alzheimer’s and dementia over the course of two years. Researchers used metabolic testing to search for biomarkers (or indicators of Alzheimer’s) in those participants exhibiting symptoms.
The study revealed three separate types of biomarkers, which could mean three subtypes of the disease. Participants with the inflammatory subtype had high levels of C-reactive proteins, produced by the liver, which increase when the body experiences inflammation. In the noninflammatory subtype there are other metabolic abnormalities but no inflammation. The third type ,which Bredesen calls cortical, is actually correlated with a substantial zinc deficiency.
Because Alzheimer’s is classified as a neurodegenerative condition, doctors don’t conduct thorough metabolic testing on patients even though metabolic conditions, like obesity, inflammation, hypertension and high glucose levels have been linked to the disease. Bredesen is careful to note in his study that this merely shows a correlation and not causation since many of the metabolic conditions linked to Alzheimer’s are increasing in developed countries.
Bredesen noted the importance of the subtypes stating:
“The important implications of this are that the optimal treatment may be different for each group, there may be different causes, and, for future clinical trials, it may be helpful to study specific groups separately.”
Do you believe that our difficulty in finding a cure or treatment for dementia could be because there are separate types of the disease? Share your thoughts with us in the comments below.