A recent study shows that older adults with elevated brain plaquing, yet normal cognition, actually do experience faster rates of mental decline as they age, suggestive of Alzheimer’s disease.1 Since Alzheimer’s disease (AD) historically has been only diagnosable upon autopsy, it has been important for researchers to uncover biomarkers which indicate disease progression. Only after such correlations have been made, will significant emphasis on prevention at early stages be advocated; those stages need to be quantified. The current study looked at amyloid levels in aging adults over a 10 year period of time to determine if such biomarkers could serve this purpose. A cognitive composite analysis was also utilized to measure more functional components of early AD progression, and could help shape early disease assessment.
Cerebrospinal Fluid Taps or Positron Emission Tomography (PET) Scans
The study looked at 445 cognitively normal individuals. Using cerebrospinal fluid taps or positron emission tomography (PET) scans, amyloid levels were measured. Of the 445 participants, 202 were found to have elevated amyloid levels. The average age of the participants was 74 years. Cognitive tests were performed, using ADCS Preclinical Alzheimer Cognitive Composite (ADCS-PACC)(2). The observation period lasted for 10 years, with an average observation per participant of 3 years.
Amyloid in the Brain
The elevated amyloid group did show significantly higher rates of cognitive decline, with 32% developing symptoms of early AD after 4 years, compared to 15% of the normal amyloid group. The elevated amyloid group did show an increased presence of the ApoE4 gene, which has been correlated with an increased likelihood of developing AD. In another aspect of the study, using global cognitive function assessments, the overall conclusion was that a majority of individuals presenting with amyloid in the brain will progress to AD over a 10 year period.
Conclusion
The study’s intention is to show that during an asymptomatic stage, people may show significant risk factors, including biomarkers and changes on cognitive function tests, such as the ADCS-PACC. Hopefully this research will help lead early prevention and interventions in the future, such as amyloid removal.
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Sources
- Donohue MC, Sperling RA, Petersen R, et al. Association Between Elevated Brain Amyloid and Subsequent Cognitive Decline Among Cognitively Normal Persons. JAMA. 2017;317(22):2305-2316.
- Donohue MC, Sperling RA, Salmon DP, et al. The preclinical Alzheimer cognitive composite: measuring amyloid-related decline. JAMA Neurol. 2014;71(8):961-70.
- Donohue MC, Sperling RA, Salmon DP, et al. The preclinical Alzheimer cognitive composite: measuring amyloid-related decline. JAMA Neurol. 2014;71(8):961-70.
Node Smith, associate editor for NDNR, is a fifth year naturopathic medical student at NUNM, where he has been instrumental in maintaining a firm connection to the philosophy and heritage of naturopathic medicine amongst the next generation of docs. He helped found the first multi-generational experiential retreat, which brings elders, alumni, and students together for a weekend campout where naturopathic medicine and medical philosophy are experienced in nature. Three years ago he helped found the non-profit, Association for Naturopathic ReVitalization (ANR), for which he serves as the board chairman. ANR has a mission to inspire health practitioners to embody the naturopathic principles through experiential education. Node also has a firm belief that the next era of naturopathic medicine will see a resurgence of in-patient facilities which use fasting, earthing, hydrotherapy and homeopathy to bring people back from chronic diseases of modern living; he is involved in numerous conversations and projects to bring about this vision.
