Potential Role of Omega-3 Fatty Acids in Neurodegenerative Disorders - Literature review Example

?Critical Discussion of the Potential Role of Omega-3 Fatty Acids in Neurodegenerative Disorders Omega-3 essential fatty acids belong to the ofpolyunsaturated fatty acids and their role in context of neurodegenerative disorders has been widely debated around the world. This literature review aims at contemplating the potential role played by these fatty acids in tackling neurodegenerative diseases in particular because it is suggested that they have astounding neurological benefits and likewise, exert a neuroprotective action to a certain extent against such diseases. It is strongly recommended by physicians and nutritionists to increase the amount of dietary omega-3 fatty acids taken daily because they are considered essential for improving neural function and development. By protecting the brain against a range of psychiatric and neurological disorders in particular neurodegenerative diseases, an adequate daily intake of omega-3 polyunsaturated fatty acids works to lend a strong protective action to the CNS. However, the actual intricate biochemical mechanisms by which these polyunsaturated fatty acids exert a beneficial influence on the brain are still not properly understood which is why this paper aims at reviewing the relevant literature so as to find out what it has to say on the relationship between omega-3 fatty acids and neurodegenerative conditions. In context of potential therapeutic actions of omega-3 fatty acids, it is claimed that most studies agree on the fact that imbalanced dietary patterns negatively influence the neurological development. One study concludes that dietary patterns are strongly associated with low Alzheimer’s disease’s risks (Gu et al. 2010, p. 699). Earlier human diet comprised of more omega-3 fatty acids than it does now. Presently, larger proportions of omega-6 fatty acids in comparison to omega-3 fatty acids make up modern human diet. It is a deplorable reality that when scrutinized in comparison to omega-6 fatty acids, human diet has been revealed to be considerably deficient in omega-3 fatty acids. Increasing evidence suggests that AD patients have deficiencies of PUFAs and docosahexaenoic acid (DHA) metabolite in the diet (Puskas 2002, p. 1580). These fatty acids are concerned with preventing and tackling severity of various neurological disorders like Alzheimer’s. They reduce the multitude of risks associated with neurodegenerative disorders the role played by DHA in this regards specially forms a bulk of research done on this subject. It is claimed that general consensus among researchers identifies that DHA is not only an approved critically important component of neurological development and brain function (Moralez da Silva 2008, p. 352) but it also plays a potential role in preventing incidence of neurodegenerative conditions. Along with a strong relationship between DHA and psychiatric conditions like depression, studies show that researchers have also found a significant relationship between diets deficient in DHA and a multitude of neurodegenerative diseases mainly common in the elderly population like Alzheimer's disease and multiple sclerosis among others (Freemantle et al. 2006 cited in Zivkovic et al. 2011). Multiple Sclerosis (MS) is another neurodegenerative condition on which much research is done in relation with omega-3 fatty acids because latter possesses high immunomodulatory actions (Simopoulos 2002, p. 495). It is concluded that diets enriched with polyunsaturated fatty acids like omega-3 fatty acids play a potentially important role in improving outcomes of MS in the affected patients. This is why many MS patients change their diet patterns believing that omega-3 fatty acids could prove to be an effective dietary intervention. It is suggested that the most common and widespread dietary interventions recommended by doctors around the world comprise of supplementation with polyunsaturated fatty acids like DHA and omega-3 fatty acids, diets based on milk and eggs, different vitamins, micronutrients, and a variety of antioxidants like selenium, Gingko biloba extracts, and coenzyme Q10 (Farinotti et al. 2012, p. 2). However, it is also argued in research literature that diet patterns in MS patients have not been extensively studied and a few studies done are poorly conducted and based on weak trials, which is why link between dietary omega-3 fatty acids and better outcomes in MS patients has not been successfully established as yet. Those claiming that omega-3 rich diets do not play a significant role in neurodegenerative diseases claim that many MS patients only begin to reconsider their diets just to acquire a sense of control over the disease. Also, not extensive but only individual findings based on disproportionate investigative methods suggest that many MS patients also suffer from different forms of malnutrition as a result of which they are encouraged to revise their diets and incorporate more sources of omega-3 fatty acids (Farinotti et al. 2012, p. 3). In another research regarding the potentially powerful therapeutic role played by polyunsaturated fatty acids in curing MS, it is claimed that both omega-3 and omega-6 fatty acids play an anti-inflammatory role against this autoimmune inflammatory disorder (Mehta, Dworkin & Schwid 2009, p. 82). Also, the study discusses how low dietary intake of omega-3 fatty acids relates with a high incidence of MS which grounds the reality illuminated by many other studies also that there is a definite relationship between dietary patterns and incidence of neurodegenerative conditions and other neurological disorders. The role of polyunsaturated fats as disease-controlling and anti-inflammatory agents has been widely examined in context of MS. A great number of studies have been done to evaluate the association between MS and diet over the past many years and though to date it is still unclear if any definite relationship exists between diet patterns and MS, one thing is obvious that both omega-3 and omega-6 fatty acids have anti-inflammatory effects (Mehta, Dworkin & Schwid 2009, p. 84). It is suggested that patients of MS often try to seek unconventional interventions when all conventional methods fail one after another. Dietary supplements of polyunsaturated fatty acids constitutes one such unconventional therapeutic approach and it is claimed by conductors of one survey that 37% of total 1573 patients of MS had taken dietary supplements of omega-3 fatty acids at some point during treatment (Mehta, Dworkin & Schwid 2009, p. 82) which grounds the significance of the role played by these fatty acids against neurological disorders and refutes the claim that there is no possibility of any consistent or durable role played by them in context of CNS disorders like MS. This is because another research related to potential neurofriendly effects of omega-3 fatty acids reveals that dietary supplementation of omega-3 fatty acids helps in reducing MMP-9 production by immune cells in MS (Shinto et al. 2009, p. 131) which is an autoimmune inflammatory disorder. It is claimed according to one survey that MMP-9 production by immune cells declined by 58% following therapeutic intervention of consistent omega-3 FA supplementation for only 3 months (Shinto et al. 2009, p. 131) which is why they are considered very important immune-modulators. In another important study primarily based on neurological benefits of omega-3 fatty acids, it is claimed that the CNS is enriched with abundant amounts of both omega-6 and omega-3 fatty acids particularly DHA which is the most abundant (Quinn et al. 2010, p. 1903). DHA in particular has neuroprotective actions and it operates in the CNS through a wide variety of mechanisms of actions which regularly overlap. Incorporation of increased amounts of dietary omega-3 fatty acids in the diet not only affect the biophysical features of the cell membrane in the CNS but also significantly influence gene expression (Jump 2002 cited in Dyall & Michael-Titus 2008, p. 222). DHA in particular has been studied to evaluate its benefits in the CNS and it is revealed that it considerably encourages the biosynthesis of phosphatidylserine which produces highly effective results in the brain. DHA-induced phosphatidylserine synthesis restricts the age-related weaknesses in cognitive ability which is why diets rich in omega-3 fatty acids could be considered an effective dietary intervention for Alzheimer’s patients. This is because DHA-induced phosphatidylserine biosynthesis abundantly improves both cognitive ability and memory (Blokland et al. 1999 cited in Dyall & Michael-Titus 2008, p. 223). This is why diets abundant in omega-3 fatty acids and supplements of DHA could prove to be effective to treat Alzheimer’s because they work to improve memory and this neurodegenerative disorder is simply considered to be the most common source of dementia in the elderly people (Dyall 2010, p. 1). However, it is also argued in research literature that only patients with very mild Alzheimer’s disease or cognitive impairment benefit from dietary omega-3 supplementation (Chiu 2008, p. 1540) and no patients with moderate or advanced AD showed obvious improvement in cognitive function (Hooijmans 2012, p. 191). It is also suggested that an imbalance in intake of omega-3 and omega-6 fatty acids gives rise to a variety of diseases but evidence regarding this matter is still not in abundance. Still, interest in the nature of role played by these polyunsaturated fatty acids in preventing different metabolic disorders is rapidly growing especially in context of CNS. This is clearly because the brain has high levels of omega-3 fatty acids particularly DHA and upon disproportionate diets or diets deficient in polyunsaturated fatty acids, CNS is directly affected in a negative manner which instigates the incidence of certain neurodegenerative conditions (Marteinsdottir et al. 1998 cited in Dyall & Michael-Titus 2008, p. 221). Animal studies show that chronic omega-3 deficiency exerts a negative influence on Na+/K+ ATPase activity in rat’s brain by drastically slowing it down (Bourre et al. 1989 cited in Dyall & Michael-Titus 2008, p. 221). The issue that most of the studies concerning effects of omega-3 deficiency are based on animals and not humans is also a matter of criticism and contributes to doubtfulness in the claim made by advocates of omega-3 fatty acids’ benefits regarding neurodegenerative disorders. Extensive research illuminates that the neuroprotective role of omega-3 fatty acids is not indicative of individual studies based on poor findings. Rather this fact can also be found in many studies that omega-3 fatty acids play a neurofriendly role for Parkinson’s disease (PD) also which is a neurodegenerative disease involving neuronal cell death (Alexi 2000, p. 409; Simonian & Coyle 1996, p. 84) in addition to Alzheimer’s and MS as discussed above. In one study based on epidemiological data, it is observed that low omega-3 dietary intake is significantly associated with PD onset because it proves to be a potential environmental risk factor for this neurodegenerative disease (Bousquet et al. 2011, p. 263). It is secret to none that after Alzheimer’s, PD is considered second most potentially dangerous and lethal neurodegenerative disorder (Reed 2011, p. 1305) and affects 1% of elderly human population worldwide (Bousquet et al. 2008, p. 1213). It is claimed that polyunsaturated fatty acids form important components of cell membranes in the brain and play a major role in regulating normal cell activity. Both omega-3 and omega-6 fatty acids must be obtained from diet (Bousquet et al. 2008, p. 1213). Omega-3 fatty acids specifically produce beneficial effects for a wide range of CNS disorders from Alzheimer’s and MS to PD and schizophrenia. As PD to date has remained largely incurable, the role of omega-3 fatty acids as an effective intervention is still considered controversial and doubtful. But observation of the varying effects produced by these polyunsaturated fats on a mouse model of PD suggested that consumption of omega-3 rich diet for consistently 10 months led to a visibly higher level of DHA in the brain. Now the mechanism of action in the study suggests that high levels of DHA exert a neuroprotective action in the brain by protecting against the devastating influence of MPTP which is a major neurotoxin responsible for nigrostriatal denervation in PD (Bousquet et al. 2011, p. 263). Basically in PD, patients suffer from a huge loss of dopaminergic neurons which is directly associated with a decline in striatal dopamine content in the brain and these study findings indicate that changing diet patterns in such a way that increased dietary intake of omega-3 fatty acids is maintained for several months significantly protects against the deleterious effects of nigrostriatal denervation in this neurodegenerative disorder (Bousquet et al. 2011, p. 263). This study also shows that dietary supplements of DHA can prove to be quite effective and should be considered when intending to achieve a neuroprotective effect in PD patients. Concluding, this much remains clear from the above discussion that omega-3 fatty acids form important structural components of the central nervous system and exist in high number due to which they are capable of influencing cellular function both directly and indirectly. There is a growing body of research which relates omegae-3 enriched diet with improved human health. In patients diagnosed with certain neurological disorders, a diet deficient in DHA and other omega-3 fatty acids forms an important common background factor. Also, omega-3 fatty acids in comparison to omega-6 fatty acids are claimed to be more anti-inflammatory and immunomodulatory in action against CNS disorders which is why the presence of these fatty acids as structural components of the nervous system holds critical importance. 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