Environmental Risk Factors
Alzheimer's disease could be caused by viruses similar to herpes. Herpes viruses (the type that cause cold sores) and Chlamydia bacteria have been proven to be a leading factor. The bacteria Spirochete (corkscrew shaped bacteria) is also a leading factor. The cause for memory loss and cognitive decline is the prevention of communication between neurons. The cause of this prevention is the buildup of sticky amyloid plaques and misfolded tau proteins in the brain. This means that the neurons can't communicate with each other. Scientist have not yet made this hypothesis official but research is being conducted
Macdonald F. (2016 Mar 11) Scientists Identify a Virus and Two Bacteria That Could Be Causing Alzheimer's. Retrieved from https://www.sciencealert.com/scientists-identify-a-virus-and-two-types-of-bacteria-that-could-be-linked-to-alzheimer-s
Macdonald F. (2016 Mar 11) Scientists Identify a Virus and Two Bacteria That Could Be Causing Alzheimer's. Retrieved from https://www.sciencealert.com/scientists-identify-a-virus-and-two-types-of-bacteria-that-could-be-linked-to-alzheimer-s
Genetic Risk Factors
No specific genetic cause for Alzheimer's disease has been found yet, but certain alleles of the apolipoprotein E (APOE) gene, on chromosome 19, may affect an individual's risk for Alzheimer's disease.
The APOE gene produces a protein called apolipoprotein E; this protein combines with fats, or lipids, in the body to form lipoproteins. These lipoproteins package cholesterol and other fats carrying them through the bloodstream.
Having these alleles does not cause the development of Alzheimer's, but these alleles can determine the risk of getting Alzheimer's
National Institute on Aging. "Alzheimer's Disease Genetics Fact Sheet." (2015). Retrieved from https://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-genetics-fact-sheet#alzheimers
Genetics Home Reference. "APOE gene." (2017). Retrieved from https://ghr.nlm.nih.gov/gene/APOE#conditions
The APOE gene produces a protein called apolipoprotein E; this protein combines with fats, or lipids, in the body to form lipoproteins. These lipoproteins package cholesterol and other fats carrying them through the bloodstream.
- APOE ε2 - A very rare allele, but may provide protection against Alzheimer's. Development of Alzheimer's in individuals with this allele will usually develop the disease later in life..
- APOE ε3 - The most common allele, and it is believed to be neutral.
- APOE ε4 - This allele increases the risk for Alzheimer's disease and is associated with early onset. A person with more APOE ε4 alleles (0-2) has a higher chance of developing Alzheimer's.
Having these alleles does not cause the development of Alzheimer's, but these alleles can determine the risk of getting Alzheimer's
National Institute on Aging. "Alzheimer's Disease Genetics Fact Sheet." (2015). Retrieved from https://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-genetics-fact-sheet#alzheimers
Genetics Home Reference. "APOE gene." (2017). Retrieved from https://ghr.nlm.nih.gov/gene/APOE#conditions
[Together in This]. ( 2016, March 31). Alzheimer's Disease - Causes and Risk Factors. [Video File]. Retrieved from https://www.youtube.com/watch?v=hSCIjJ8yKy4&feature=youtu.be