Link between Alzheimer’s and Periodontal Diseases

Introduction

Recently, the scientists have begun to argue about the interconnection between the oral bacteria and the development of Alzheimer’s disease. In the process of laboratory researches and analyses, it has become possible to examine the existence of certain oral bacteria in the patients with brain tissues’ traumas or disorders. Such a result has provided modern medicine with the new hypothesis about the link between periodontal and Alzheimer’s diseases. Nevertheless, although this issue has raised heated debates and discussions in the scientific world, its factual evidence and proofs are still absent.

At the same time, it is important to conduct the further investigations and studies as the revelation of this connection can considerably help in the treatment of Alzheimer’s disease as well as some other chronic illnesses. Since Alzheimer’s disease tends to affect more and more people nowadays, it is essential to analyze its nature and triggers in order to react to its symptoms and development correspondingly. From this point of view, the investigation of the link between periodontal and Alzheimer’s diseases is an important issue, which can significantly contribute to the understanding of the mechanisms of both disorders and the ways of overcoming them.

The Nature of Alzheimer’s Disease

Alzheimer’s disease is one of the most striking and dangerous illnesses, which usually affects the elderly population. It is a kind of progressive dementia, which results in the short-term memory impairments. It is estimated that approximately 4.5 million people in the US are suffering from this mental disorder (Larson et al., 2004). According to the statistical data and the conclusions of experts, the number of affected individuals shows a tendency to increasing. Annually, the US spends about $100 billion to cover the treatment of Alzheimer’s disease (Richards & Hendrie, 1999). Without doubts, there is a pressing need to examine this disease more precisely for the sake of the well-being of the nation in particular and the global community in general.

The development of Alzheimer’s disease is evaluated with the help of cognitive assessment tools. In fact, the primary symptoms of this disorder bear a certain resemblance to other forms of dementia and mental illnesses. Nevertheless, the further development of the disease is characterized by the deterioration of the quality of brain activity and mental processes. Thus, people affected by Alzheimer’s disease find it difficult to concentrate attention, memorize new material, arrange their speech fluently and quickly and orient easily in space and time. In addition, the signs include oppressive mood, confusion, short-term memory impairments, and some personality changes. The danger consists in the permanent progression of the disease, unless there is an effective program of treatment. However, even modern methods and tools of treatment of Alzheimer’s disease do not help to overcome it completely.

Commonly, the appearance of Alzheimer’s disease is connected with the presence of some pathological processes and structures within the human organism. The pathologies include the so-called senile plaques, which involve the existence of neuropil threads, neurofibrillary tangles and beta-amyloid plaques (Wu & Nakanishi, 2014). Nevertheless, it becomes obvious that the mere presence or lack of those pathologies does not indicate the appearance of the disease. Therefore, there is a need to find more striking and evident features and symptoms of Alzheimer’s disease to understand it properly.

In fact, the mechanisms, which activate Alzheimer’s disease, are not discovered yet, although contemporary medicine presupposes the existence of certain indicators, which witness the connection between the inflammatory processes and Alzheimer’s disease. They have examined that the emergence of any inflammations in the human body leads to the appearance of certain bacteria and microorganisms, which can cause the development of some mental diseases, in their turn (Singhrao et al., 2014). Modern neurology does not doubt the existence of such a link between the brain injuries and inflammatory bacteria. Thereby, the hypothesis about the link between the periodontal and Alzheimer’s diseases has a solid footing to fall back on.

An Overview of Periodontal Disease

Similarly to the situation with Alzheimer’s disease, the periodontitis is another serious health problem in the modern world. According to some estimates, the number of affected people tends to grow while the forms of the disease become more severe and dangerous. In fact, periodontal disease is the consequence of the correlations between the tooth-associated microbes, situated in the mouth cavity, and the natural organism’s response to their emergence. The matter is that oral bacteria contain various forms of the gram-negative anaerobes, which encourage a host response. As a result of this interrelation, the organism starts producing inflammatory cells with the main purpose of overcoming the infection.

Although a host response is a natural protective mechanism, its consequences may pose a threat to the work of the whole organism. Thus, the production of the inflammatory mediators can lead to the destruction of alveolar bone and connective tissue. Besides, it may cause the pathogens of the oral tissues and cells as well as affecting the local areas with primary inflectional injury. However, the process can also affect some other systems and organs of the body, including the cardiovascular system and brain activity.

Currently, Singhrao et al. (2014) argue that poor oral health and the existence of periodontitis is one of the main causes of many chronic diseases, including atheroma formation, diabetes, thrombosis, weakening of the immune system and others. So far, this list also names Alzheimer’s disease and provides the corresponding evidence and explanations.

The Link between Alzheimer’s and Periodontal Diseases

It has been analyzed that the patients with good oral health are less prone to serious chronic diseases and mental disorders. The matter is that the absence of any dental diseases presupposes the small amount of pathogenic bacteria within the mouth cavity. As a result, their circulation through the organism is relatively small and unnoticeable. However, the emergence of periodontal disease increases the amount of bacteria tenfold. Correspondingly, a great number of inflectional bacteria reach the bloodstream and affect various organs. This is true in relation to the brain tissues as well.

In addition, periodontal disease presupposes the presence of some gram-negative bacteria, which are able to infect some areas of the brain. Nowadays, Licastro, Carbone, Raschi, and Porcellini (2014) admit that periodontal bacteria can reach the brain through the trigeminal nerve and cause the infection within some of its areas.

It is also possible to assume that the matter of link between periodontal and Alzheimer’s diseases does not consist in the very process of infection. Another hypothesis predicts that oral bacteria do not infect brain cells but cause the conditions of the continuous inflammatory process, which exhausts and affects the work of all organs, including the brain (Poole, Singhrao, & Crean, 2014). Since the production of inflammatory mediators can strongly affect the work of cardio-vascular system, it can also negatively influence the brain activity at the same time (Cerajewska, Davies, & West, 2015).

It is also studied that the inflammatory processes can spread through the permanent systemic circulations throughout the body, leading to the increased amount of serum antibodies and acute phase reactants (Sparks Stein et al., 2012). Furthermore, the daily circulations of the oral bacteria in the bloodstream can lead to the conditions of the elevated inflammatory products.

As it was already mentioned, periodontal bacteria affect the cardiovascular system and can result in the heart strokes. In fact, the affection of the work of heart can also lead to Alzheimer’s disease. De la Torre (2006) admits that patients with Alzheimer’s disease usually have a history of heart strokes. Furthermore, during a long period, heart strokes were regarded as major causes of Alzheimer’s disease (De la Torre, 2006). Therefore, the link between the three injuries, including the periodontitis, strokes and Alzheimer’s disease, can exist. It is possible to surmise that inflectional oral bacteria do not injure the brain directly but affect it via the other organ systems.

Conclusion

To sum up, the connection between periodontal infections and Alzheimer’s disease is of great interest for the scientific researches. So far, there exists some prolific evidence, which witnesses the possibility of the relationships and correlations between two diseases. Thereby, on the one hand, the periodontitis causes the appearance of oral bacteria, which are capable of infecting brain tissues and cells directly. On the other hand, the connection between two disorders may be explained by the presence of the inflammatory processes in the body, caused by the host response to the oral bacteria. In any case, poor oral health remains a major risk factor, leading to further infections and injuries of the brain.

Both periodontitis and Alzheimer’s disease remain significant and disturbing problems in the modern world. From this point of view, there is a need to conduct further studies and examinations in order to reveal the main peculiarities and mechanisms of those disorders. The comprehension of their nature is the key point of success in their treatment and prevention. Currently, many scientists should work over the data collection and analysis, witnessing any links between Alzheimer’s disease and the inflectional or inflammatory processes within the organism.