As the most recognizable risk factor, “Aging is accompanied by the systematic deterioration of the condition over the whole body” (Peng, 2017). The risk of developing AD periodically starts at 65 years old, while the chance arises to about 40% for people are 85 years old or older. The source of AD is based on energy supply for brain functions that is related to the decline of brain perfusion that starts at 22 years old of a person. Moreover, the characters of an aging brain includes up-regulation of immune response and down-regulation of synaptic transmission which associates with occurrence of AD. On the other hand, AD is a process of accelerated aging.
According to epidemiological studies, females have a higher chance of developing AD than males do, even though the cause is unknown at the moment. Females’ higher incidence of AD is responded by decreasing estrogen levels at older age. The widespread of immune response consistent with the acceleration of aging scenario in female brains. Further clarification of the gender differences on AD requires better understanding of the network in brain.
Higher risk of growing the disease is also associated with lower education. The process of education sophisticates brain wiring. The lower education is provided to the brain, the less complex brain network is. According to the “brain reserve” hypothesis, the non-complex brain is more susceptible for breakdown and the rate of being diagnosed AD declines in people with higher education.
High risk of occurring AD is linked to the exposure in unhealthy environment. The peripheral biomarker change lead by long term exposure in the environment with high concentration of fine particulate matters. High concentration of pesticide is also positively related with high risks of AD. Those environmental exposure may directly occur through normal inhalation or indirectly transport to the blood-brain barrier.
Lifestyle can significantly develop or prevent the occurrence of AD in the person. By disrupting the global metabolism, smoking cigarette and drinking alcohol exert epigenetic modification in a person’s brain which connects to the growth of AD. Despite, a positive, protective effect can be given to the person by having active lifestyle such as, physical exercise, social communication, music and arts activities.
The risk of AD is elevated with certain medical histories such as heart disease, or type 2 diabetes. Through increasing brain amyloid load, periodontal disease correlates with the growth of AD. Certain bacterial infection also associated with high level of immune response. Including both notably sleep and sleep postures can change the removal of amyloid. Those diseases are able to be prevented which decrease the risk of AD with certain diets such as “Minimize your intake of saturated fats and trans fats” (Barnard, 2017), reserving daily vitamins from food sources instead of piles, and taking more vegetables, legumes, or fruits than meat and diary.