What exactly is Alzheimer's disease?

Alzheimer’s disease (AD) was a disputatious topic since long time ago which some researchers such as Jay W. Pettegrew, Matcheri S. Keshavan, Nancy J. Minshew and so forth who put forward the statement of AD was origin by nature factors while some researchers such as Krysten K. Fulcher, Michael L. Alosco, Lindsay Miller and etcetera propose that AD was cause by nurture factors. Even though there are more than 70 diseases that lead to dementia, AD is the most serious compare to the other disease and accounts for 50-70% of dementia (Akter, Rani, Nordin, Rahman, Aznan & Rathor, 2012). The characteristics of AD which involve the patients in numerous areas has become a medical and social challenge for nowadays society, follow with the need for diversity of professional development in fulfilling the need of patients and their caregivers (Cobos & Rodríguez, 2012). AD is considered as multifactorial disease, with no single cause known, and some modifiable and non-modifiable risk elements are connected with the development and progression of AD (Korolev, 2014). As there was a finding which the prevalence, incidence of AD, brain structure and function were vary by the sex and gender as well (Mielke, Vemuri & Rocca, 2014).

Nature

Nature e lement that lead to the causes of AD is biological factor such as death of brain cells, neurodegenerative type of dementia and etcetera. AD is characterized by an irreparable, continuous loss of memory and cognitive skills which can occur in rare familial cases in the third decade (Bekris, Yu, Bird & Tsuang, 2010). The phosphomonoesters (PME) in the brain of AD patients is increase at the beginning of the course of AD, follow with the enhanced of phosphodiesterase (PDE) and likely reflect the commencement of membrane degenerative changes (Pettegrew, Keshavan & Minshew, 1993). AD is a continuous neurodegenerative brain disorder which causes a significant disruption of ordinary brain’s structure and its function (Korolev, 2014).The changes of AD patients are distinct with other brain’s disease patients which the PME and PME were in the opposite direction changes (Pettegrew, Keshavan & Minshew, 1993). Besides, there was a study of microscopic examination toward AD by the researchers from the departments of pathology and clinical neurological sciences, University of Western Ontario and the division of neurology, department of medicine of University of British that show the critical features of the patients. The cerebral cortex of AD patients was peppered with neurofibrillary tangles and senile plaques. (Munoz & Feldman, 2000). Hence, AD was known as dementia related with these histopathologic abnormalities that existed. At present, histopathological examination toward the brain using modern molecular-biological ways beneath standardized situations is the ‘gold standard’ for AD diagnosis (Jellinger, 2015).

Furthermore, Deoxyribonucleic acid (DNA ) methylation is 1 of the origin of AD. DNA methylation is a major regulator of transcriptional activity, and divergence in the distribution of the epigenetic mark that involved in numerous of neurological disorders such as Alzheimer’ s disease and etcetera (Sanchez-Mut et al ., 2013). In this study, DNA methylation clustering analyses have indicated cerebral cortex as distinct branch that relevant to the understanding of AD due to that region is most strongly effected in the neurological disorder (Sanchez-Mut et al., 2013). Therefore, the researchers have made a detailed comparison of DNA methylation patterns in cerebral cortex and the other part of the brain, the latter being regions which are not targeted in AD. The mice samples were first been utilized in this study and the result linked the presence of hyper-methylation events in cortex from Alzheimer’s mouse to the relevant transcripts and the proteins which detect by western blot of F2rl2, Sorbs3 and Spnb4 genes and immunofluorescence of Tbxa2r

From the result of mice samples study above, the urge to continue the investigation on human biological samples whether epigenetic changes happened in AD patients by the researchers is enhanced. The study was continue by using human biological samples and same trend was observed

Nurture

On the other hand, for the studies on nurture contributors of AD such as stress, environment, life style and etcetera have been carry out year by year to obtain new intervention in dealing with AD. The finding of monozygotic twins by a group of researchers that not necessarily both have AD suggests that environmental factors have involved in development of AD as well (Munoz & Feldman, 2000). Daily physical activates play a role in the AD as well. There were evidence showed that among elderly patients demonstrates that higher level of daily physical activity will lead to drop of the risk for AD (Fulcher et al., 2014). The participants in the study of Krysten K. Fulcher and his career in year 2014 were around 50-85 years old, have a documented history of Heart Failure (HF) and the participants with a history of neurological disorder such as stroke and AD as well. Interestingly, this study have showed that participants who were older adults with HF that demonstrates higher levels of daily physical activity were better cognitive performance. This study provide a path for further studies to defecate the mechanisms linking physical activity and cognitive function in HF patients and the effectiveness of improvement in cognitive function with the interventions of enhance activity levels toward the population. Moreover, AD impact the patients in the variety areas, the considering on other alternate behavior besides pharmacological treatment and biological discover, although seeming to ease the development knowledge toward the AD (Cobos & Rodríguez, 2012). In simple word, researches toward the nurture contributor were still limited currently. For example, the study of relationship between Education and Dementia in year 2011 have report that there were not clear evidence to show that the AD prevalence studies have larger risk compared to AD incidence studies (Sharp & Gatz, 2011). More investigation should be carry on instead of the focus on biological aspects only.

Education level of an individual have contribute to the AD causes as well. Throughout the study of Cognitive reserve in ageing and Alzheimer's disease by Yaakov Stern in year2012 have indicate the relevant between the academic level and AD pathology. The positron emission tomography (PET) scan illustrate the blood flow in the parietotemporal area for the researcher to study on it. The study have the finding that the highest educational level AD patients have, the darkest blue in the parietotemporal area which mean the lower level of blood flow and have more advanced AD pathology compare to the lowest educational level AD patients (Stern, 2012).

In addition, the study by Richard Schulz and Gail M. Williamson in year 1991 had look into the relationship of caregivers and the AD patients. This study were a 2 years longitudinal study which show strong evidence that patient decline and high levels of depressive symptomatology for the caregivers. Caring for the AD patients will have unexpected high emotional, physical and financial costs toward the caregivers. The reported was mentioned that female caregivers were high, stable rates of depressive symptomatology throughout this study, whereas male caregivers showed significantly enhances in depression over time (Schulz & Williamson, 1991). From this study, the needed of new and more well intervention to lend a hand in dealing with AD in nowadays modernization society can be observe.

In the nutshell , both perspectives have the explanation and facts that contribute to the AD. However, the prevention and intervention toward AD were still limited and further development ought to be focus on it to bring new hope for latest generation instead of keep discover the main causes without improvement in dealing with it as according to World Alzheimer report (Wimo & Prince, 2010), by year 2030 the figure will increase until 65.7million, rising to 1154.million by year 2050. Currently, there is no cure for AD, and drug therapy for the AD is still in its beginning step (Korolev, 2014). It is a critical public health issue in USA and other countries, with a significant healthy, social and financial issues toward nowadays society. Together with the costs beget by the disease, proximate 604billion dollar worldwide, has led the conclusion of reports that AD is the most significant crisis of century in socio-medical terms (Cobos & Rodríguez, 2012 ).

Arguments

There are still some arguments that the cause of Alzheimer Disease (AD) is by nature or nurture itself in spite of many researches and experiments being carried out. From nature factors perspective, human are made up of cells and each cell contain a unique genetic coding that is heredity from our parents or ancestors. There are past medical reports and researches which had found that hereditary is one of the reason that contribute towards Alzheimer disease, as the affected person concerned had inherited from one of the affected parent or we can call it gene mutation. Alzheimer diseases in the early-onset form is inherited in an autosomal dominant pattern, meaning that a copy of altered gene in every cell is enough to causes the disorder. When mutation of gene occurs it will affect a protein named bate-amyloid, when there is build-up it will then cause damages to the brain. Additionally, all genes that are identified in the Alzheimer diseases are dominant. This means although it is inherited from either one of the parent, this particular gene will still show its effect as it is a dominant gene. So due to the genetic characteristic from our ancestors there will be a higher chance of getting AD if there is a past family medical history.

Another important factor is due to ageing. As we are getting older, the chances of getting AD increase gradually. There is evidence from study showing that the increase of AD incidence from 2.8% per 1000 person from the age of 65 and 69 years old increases to 56.1% per 1000 persons for the people whose age are older than 90 years old. That means among 1000 people, people who get AD increases from 28 person age between 65 to 69 years to 561 persons that age 90 years and above. This strongly prove that AD incidence are really related to the ageing effect of human.

In the nurture side or environmental factor that may also causes AD, the most famous study should be the twin method where the result shows that a pair identical twins or can we say monozygotic twins, where one of the twin develop AD does not mean the other twin may develop too. This shows that environmental factors may also play an important role in developing AD.

High income countries show a lower number of people with dementia if compare with lower and middle income countries . This is because the medical healthcare for dementia is relatively high in the lower and middle income family as they may not have enough money to seek for proper healthcare as dementia may eventually lead to AD. However, if we compare to a high income family that can afford specialist healthcare services then chances it may eventually prolong the period of turning into AD or even possible treatable. Furthermore, researchers suggest that to have a lifetime of mentally stimulating activity have a higher level of formal educational which is from the cognitive reserve hypothesis . This is because the theory suggest that a people that had a higher educational level example PHD holder will have a better strategies to memorize new information and are able to cope better when there is a disease attacking the brain memory centre compare to someone with lower educational level that had a poorer memory strategies to draw upon. Once again, this prove that higher income family had a lower possibility of getting AD as they have the financial support for better healthcare for earlier treatment and diagnosis. Besides, they had the opportunity to further their educational level and keep on actively improve their brain capacity and also memorising strategies compare to the lower and middle income family that had limited financial support for treatment and education.

Next, let us experiment with sex or gender difference. Since there is a biological difference between male and female sex chromosome (XX and XY chromosome). Women are significantly higher to prevail from getting AD compare to men. A reason that explains this is because women tend to live longer than men and since the older the age the higher the less possibility for the incidence. Lastly, there are also other environmental factor like high blood pressure, Huntington diseases, head injuries that may help to increases the risk of AD developing in many circumstances.

Concluding, there are still no medical study or research that show Alzheimer diseases is fully cause by just one nature or nurture because it still depends on how well the gene that a person inherited from the parents or a person life style. Finally, we believe there are still many unaccounted conditions that will affect the result of this study.