Good Case Study On Risk Of Alzheimer’s Disease
HYGIENE IN WEALTHY NATIONS MAY INCREASE
Introduction p. 3-4
Physiology of Alzheimer’s Disease p. 4
“Friendly” Microbes p. 4-5
The Hygiene Hypothesis p. 5-6
The International Impact of Research p. 6-7
Age-Standardized Data p. 7
Bacterial Introduction During Oral Care p. 7-8
Skeptics of the Hygiene Hypothesis p. 8-9
Conclusion p. 9
Bibliography p. 10
Hygiene in Wealthy Nations May Increase Risk of Alzheimer’s Disease
Thousands of people are diagnosed with Alzheimer’s disease worldwide every day (WorldLifeExpectancy 2011). Patients change behavior, hallucinate, and lose the ability to talk, think, and remember their lives (Alzfdn.org 2015). Alzheimer’s is not a normal part of aging and the first patient was diagnosed by Dr. Alois Alzheimer in 1906. Today, the country with the highest percentage of deaths attributed to Alzheimer’s disease is Finland with almost 35 deaths per 100,000. The United States is ranked #3 with almost 25 deaths per 100,000. In Britain, one in three of citizens over the age of 65 are expected to develop the disease, with 500 new cases daily and 800,000 lives affected (Agencies 2013). In 2007, the Alzheimer’s Society announced unless a cure or significant preventative treatment is found by the year 2050, 1 in 85 people (or 160 million) people will be living with the disease (Alzheimer’s Society 2007). The cost to the United States is estimated at $1.2 trillion annually (alz.org 2015). Currently, one additional person is diagnosed with the disease every four seconds. In a survey conducted by the HBO Alzheimer’s Project/Harris interaction Census (2009) more than half of the respondents reported knowing someone currently with the disease or who had it before they died.
The effect Alzheimer’s disease on society may start with the patient, but it does not end there. Included in the circle of involvement are funding sources, caregivers, and families and friends. Johns Hopkins Bloomberg School of Public Health states 43 percent require care equal to a high-level nursing home. Caregivers living in the home are required to forfeit their income from employment to care for the Alzheimer’s patient, affecting the entire family financially; this doesn’t include the stress exerted on the family members as the loved one deteriorates (MedicalDaily 2014). Over $604 billion was spent in 2004 across the world for patient care and in the United States the cost of treating and caring for patients with Alzheimer’s in 2014 reached $214 billion. While insurance companies cover some of the cost, the majority of the expense falls to the government for the elderly patient without funding for care. Aside from the diversion of funds from other causes, Alzheimer’s treatment is a burden on government budgets.
In a search for the cause and possible prevention and cure of Alzheimer’s, a correlation between good hygiene and the occurrence of the disease has been discovered. Countries with advanced healthcare record the highest incidences, but research must determine if good oral care is the source of the blame.
2. Physiology of Alzheimer’s Disease:
Alzheimer’s disease is based in the neurons of the brain (Alzfdn.org 2015). The neurotransmitter, acetylcholine, is produced there but there neurons lose connection with other nerve cells and die. When neurons die in the hippocampus section of the brain, the patient loses short-term memory. When the cells fail in the cerebral cortex, the faculties of judgment and language skills decrease. The plaques consist of amyloid and the tangles are comprised of neurofibirils (Myers 2006). Without the presence of the amyloid plaques and the neurofibrillary tangles in the brain, the deceased patient is ruled out of the diagnosis of Alzheimer’s disease. The plaques may appear years before behavioral symptoms appear and form when beta-amyloid pieces of protein create clumps. It is possible they inhibit passage of signal between the cells at the connections. The beta-amyloid is generated from the fatty membrane around the neurons and may also trigger cells in the immune system, resulting in inflammation and ingestion of disabled cells (Alz.org 2015).
3. “Friendly” Microbes:
Evolution, Medicine, and Public Health magazine published the results of a study on microorganisms that activate the immune system; specifically, microbes residing in dirt, feces, and animal dander (Fox et al 2013). Since the 1900’s, global urbanization created a living environment with limited exposure to the “friendly microbes” necessary for immune system regulation. The introduction of clean drinking water, transportation without animals and over paved roads, and antibiotics decreased exposure to microorganisms that stimulated white blood cell development. Regulatory T-cells in particular attack foreign bodies in the bloodstream (agencies 2013).
In addition to destroying bloodstream invasion, T-cells curb hyperactivity in the immune system. If regulatory T-cells become dysfunctional, autoimmune disorders and inflammation result. The type of inflammation created is often found in the brain on autopsy of victims of Alzheimer’s disease. The hygiene hypothesis postulates the peak times of activity for regulatory T-cells during adolescence and middle age create a predisposition for Alzheimer’s later in life.
4. The Hygiene Hypothesis:
A reason for populations in a country to shift from the country to the city is health related. As children are born into small rural communities, they survive and mature. The economy of the village can’t support more than a specific number of people and a migration occurs for employment. But cities in developing countries face problems with sanitation for increasing numbers of people. As a nation becomes industrialized and urbanized, one of the first areas of change is improved sanitation. Personal hygiene promotes prevention of diseases such as ringworm, lice, and dental cavities (CDC.gov 2015). The majority of public diseases are caused by fecal matter and providing water free from contamination helps prevent illnesses like diarrhea. Adequate sewage systems address problems like hepatitis A. While these actions are powerful for improving the health of a general population, there may be drawbacks in terms of an individual’s response to contaminants when contact is made. Statistics point to industrialized nations with good hygiene significantly higher incidences of Alzheimer’s in the populations. In addition, people suffering from allergic responses such as eczema and asthma also shown in increase (Mailonline 2013). For instance, children growing up with pets are less likely to develop allergies.
Dr. Molly Fox and Gates Cambridge Alumna conducted research at Cambridge’s Biological Anthropology division on the hygiene hypothesis (Science Daily 2014). Fox predicts increases in Alzheimer’s in the populations of developing countries as they increase sanitation measures to address other diseases related to clean water and hygiene. The use of age-standardized data allowed comparison across 192 countries as though they had the same age structures, life expectancies, and birth rates.
5. International Impact of Research:
The United Kingdom and France have entire populations with clean drinking water with 43 percent living in urban areas. They also have Alzheimer’s rates nine percent higher than average (agencies, 2013). However, less than half the people of Cambodia and Kenya have access to clean drinking water and those countries have an incidence rate significantly lower. The variation in rate of occurrence of Alzheimer’s accounts for 43 percent between different countries. Very low rates were found in Iceland and Switzerland; in those countries, 12 percent more were affected than in Ghana and China. The infection rates in those countries were high. Life expectancy apparently does not play a role.
Less than 10 percent of the populations of Nepal and Bangladesh live in urban areas, and their incidence of Alzheimer’s is 10% lower than in Australia and the United Kingdom. It also affects fewer numbers in China, Latin America, and India that in European countries. The differences are accounted for by levels of infectious disease, sanitation, and organization. In developing countries, rates of dementia doubled every 5.8 years when compared with countries with low income; these countries doubled their Alzheimer’s patients every 6.7 years.
6. Age-Standardized Data:
The use of age-standardized data is important when discussing the results of the study conducted by Fox. It reflects the numbers of cases of Alzheimer’s as a single summary number as if the populations compared had exactly the same distribution of ages (WHO 2012). The process has been improved by research performed by statisticians over the past 50 years. It adjusts the crude estimates of populations to reflect sex and age in most middle and low income countries. It allows easier interpretation of the collected data for comparison.
7. Bacteria Introduction During Oral Care:
The University of Central Lancashire School of Medicine and Dentistry suggests gum disease and poor mental health may be associated with dementia Alzheimer’s disease (Locke 2013). The study found Porphyromonas gingivalis, a disease bacteria linked to a specific gum disease, in the brains of dementia patients. Four out of ten patients demonstrated the bacteria on autopsy. Ten patients without Alzheimer’s were used as a control, and the bacteria was not present in those brains.
The bacteria may find entrance to the brain through daily activities like tooth brushing and certain dental procedures. Subsequent responses by the immune system may lead to memory loss associated with nerve cell death. The bacteria may also worsen conditions already present and accumulates over a period of years. While the study found the presence of bacteria related to gum disease in the brain, it does not prove it is responsible for the occurrence of Alzheimer’s disease. However, the study suggests regular visits to dental hygiene professionals may affect health outside the teeth and gums.
Peridontal disease affects approximately 100 million people in America. Oral bone is destroyed by P. gingivalis, which creates inflammation. In addition to the possibility of opening pathways for Alzheimer’s, other diseases such as stroke, diabetes, premature birth, and atherosclerotic cardiovascular disease are possible.
8. Skeptics of the Hygiene Hypothesis:
Fisher Foundation scientists view studies such as those conducted by Fox with a degree of skepticism (Locke 2013). They discuss the possibility of poorer nations lacking the ability to effectively report incidences of Alzheimer’s due to limited access to the tests required for diagnosis of the disease. In addition, the difference between wealthy countries and poor ones are wider than microorganism exposure. The head of research at Alzheimer’s Research in the United Kingdom, Dr. Simon Ridley, suggests the presence of P. gingivalis in the brain of Alzheimer’s patients may be a result of the difficulty providing adequate oral hygiene for them rather than a cause for their disease. He believes future studies look at previous dental records of the patients to correlate oral hygiene prior to developing symptoms. Dr. Ridley states that if P. gingivalis can be used as an indicator for Alzheimer’s disease, creation of a simple blood test should be the purpose of future research.
Dr. James Pickett, head of research at The Alzheimer’s Society, states other lifestyle factors such as education, diet, and other health practices should not be ruled out. While the Health Hypothesis is an interesting theory, he continues to promote exercise and healthy eating habits, non-smoking, and keeping cholesterol levels and blood pressure in check as a front line of defense against developing Alzheimer’s disease.
Developing countries demonstrate more than 50 percent of patients living with symptoms of Alzheimer’s disease; by 2025, it is expected to be more than 70 percent (Fox et al 2013). She also believes there needs to be a balance between exposure to friendly microbes and good hygiene. However, further research is necessary to definitively state good hygiene is responsible. If it proves to be so, development of new strategies is indicated for methods to prevent the triggers for Alzheimer’s from occurring. Pharmaceutical solutions and possible changes in lifestyle could save millions of people suffering from the disease. The Centers for Disease Control and Prevention promote good hygiene to stop the spread of illness and hygiene-related diseases (CDC.gov 2015).
There is an adage about statistics: Since almost everyone involved in war likes to eat pickles, pickles must cause wars. In that light, improved hygiene in wealthy countries may or may not be responsible for increased incidences of Alzheimer’s disease in their populations. Other possible relationships demand further investigation.
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