A high concentration of homocysteine is believed to increase the hazard for an person to acquire cardiovascular disease, although cut downing this degree may non assist to halt such a disease from happening. Research has shown that the high degrees of homocysteine could lend to atherosclerosis in three ways:
Has a harmful consequence that straight affects and amendss the inner cell liner of the arterias
Cloting factor activity being hampered by the high homocysteine concentration
Low-density lipoproteins ( LDL ) being oxidized more easy ( Mediniche 2009 )
Homocysteine is a merchandise ensuing from the metamorphosis of the amino acerb methionine and is known to damage blood vass. The figure below shows a portion of the methionine tract and how homocysteine can be metabolized. It besides shows how homocysteine metamorphosis is affected by vitamin B12 and vitamin Bc.
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Figure 2: Methionine Metabolic Pathway ( Journal of the American College in Nutrition 2010 )
This increases the potency for cholesterin buildup in the blood stream. The lacks of vitamins such as folic acid ( B9 ) , vitamin B6 ( B12 ) and cyancobalamin ( B6 ) have been shown to take to the addition of homocysteine degrees. Although a high homocysteine degree is frequently linked with cardiovascular diseases, the presence of familial mutants in an person is another factor that may lend to the surplus. This familial status is known as homocystinuria.
In this status, an enzyme lack causes the homocysteine degrees in the blood to increase and roll up in the blood and is excreted in the piss. However, research has shown that people with vitamin B lack ( therefore taking to a high homocysteine degree ) have a lower degree of homocysteine than people with familial mutants ( Genetics Home Reference 2010 ) .
After clinical surveies of homocysteine in the blood, the ‘normal ‘ degree of homocysteine has been considered to be about 6 Aµmol/l. Womans have been known to be less prone to cardiovascular disease than work forces. This could be explained due to findings that show adult females have significantly less homocysteine in their blood than work forces. Vitamin B addendums have besides been thought as a solution to high homocysteine degrees, and this will be discussed subsequently on. However, the issue now is whether take downing the sum of homocysteine in the blood really decreases the cardiovascular hazard. Taking into premise that a lessening in the hazard of acquiring cardiovascular disease can so be done by merely increasing Vitamin B, the ingestion of nutrient merchandises such as orange juice, breakfast cereals, fruits and veggies, all nutrients rich in Vitamin B, has been widely recommended by research workers. These beginnings of nutrient are rich in folic acid, which is vitamin B9. Research workers have besides looked into a cistron that helps to modulate homocysteine, known as methlenetetrahydrofolate reductase ( MTHFR ) ( The Institute of Nutritional Medicine & A ; Cardiovascular Research 2010 ) .
Relation of Cardiovascular Disease with Escalated Homocysteine Levels
As mentioned before, high homocysteine degrees can increase the hazard of cardiovascular disease. In fact, high homocysteine degrees may increase the happening of coronary artery disease and thrombosis in an person.
One of the ways is harming and damaging the inner cell liner of the arterias, doing endothelial cell hurt and leting LDL molecules to adhere to the inner cell run alonging more easy. Endothelial cell hurt compromises the vascular wellness by suppressing styptic procedures such as fibrinolysis, doing the organic structure to be unable to interrupt up the coagulum. One of the of import systems used by endothelial cells for ordinance involves nitric-oxide synthase ( eNOS ) , which uses I-arginine to organize azotic oxide ( NO ) and citrulline. These endothelium-derived NO serves assorted maps such as the maintaining of vas tone and suppressing thrombocytes. Endothelial cell hurt will do a decrease in the handiness of these cells and do inauspicious effects of coronary artery disease and thrombosis.
High homocysteine concentration promotes coagulums by thrombocyte activation and protein C activation, haltering their normal activity. Increased degree of homocysteine concentration can do a alteration of anticoagulant belongingss of the endothelial cells into a procoagulant phenotype that can do impaired map of the vascular endothelium, or heightening lipid oxidization. It affects the normal curdling and fibrinolysis that increase the hazard for a venous thrombosis. High homocysteine concentration besides promotes the oxidization of LDL, which is known to lend to atherosclerosis.
High homocysteine degree can besides do lessening the look of thrombomodulin and addition activity of tissue factor. This thrombosis cause by homocysteine may be the trigger for obstruction of the vass if the patient is already enduring from a certain grade of coronary artery disease. This thrombogenic consequence due to high homocysteine degree is one of the grounds why it is associated with increased hazard of CVD.
Homocysteine is shown to hold inauspicious effects on smooth musculus cells by bring oning the look of cyclin A cistron and bring forthing increasing sums of cyclin-dependant kinase, which is a regulative protein in mitosis. These actions will take to the increased in smooth musculus cell proliferation that will advance coronary artery disease and thrombosis. Surveies have been done utilizing familial techniques such as cistron look arrays to see the potentially infective alterations in the cistron look upon exposure of endothelial cells to high homocysteine concentrations ( The American Journal of Clinical Nutrition 2000 ) .
Consequence of Smoking on Homocysteine Levels
Harmonizing to surveies done, it has been shown that smoke does increase one ‘s homocysteine concentration. Smoking has already been labelled as a hazard factor of cardiovascular disease. When looking at whether or non smoking can increase the homocysteine concentration, the consequence of smoke and its chemicals on the vitamin B12 and vitamin Bc, which are involved in the methionine tract, must be observed.
First, smoke is known to do alterations in the diet of an person, and this may take to a lessening in the ingestion of indispensable vitamins. In the instance of homocysteine concentration, vitamins B12 and vitamin Bc are of import in the transition of homocysteine to other signifiers. Besides, smoking may diminish vitamin B12 and folic acid ‘s eagerness for hepatic consumption, and therefore may increase elimination of such substances through the piss. Therefore, lack and deficiency of consumption of dietetic vitamins will ensue in a rise in homocysteine concentration ( Flatt 2006 ) .
Smoking increases the nitrile degrees in the blood, and a high affinity exists between cyanide ions and vitamin B12, which is needed to change over homocysteine to methionine in the tract. Therefore, with a lessening in the sum of B12 available in the blood, there will be less methionine being formed, and there will be an accretion of homocysteine, taking to high homocysteine degrees ( Cambridge Journals 2003 ) .
In relation to folic acid, research has shown that folic acid coenzymes may be affected by the many chemicals found in coffin nails, or by the different pro-carcinogenic tracts initiated by smoke, which might take to uneffective molecules of folic acid that are unable to transport out any activity ( Wierzbicki 2007 ) .
With respects to the information above, different surveies on how smoking affects the B12 and folate concentration in the blood have led to different consequences, and therefore may turn out to be inconclusive.
Relation of Folate/B12 Supplements with Homocysteine Levels
As mentioned above, B6 and B12 vitamins and vitamin Bc are involved in homocysteine metamorphosis, as they help to recycle homocysteine into methionine. When there are B6 and B12 vitamins or folate lack, an addition in homocysteine degree could be expected because the recycling procedure is inefficient and therefore doing deficient map of methionine synthase. Methionine synthase is an enzyme that is responsible for the production of methionine from homocysteine in which homocysteine is used as a substrate ( Harvard School of Public Health 2010 and Office of Dietary Supplements 2010 ) .
Surveies have shown that a high degree of folic acid and B vitamins such as vitamins B6 and B12 in the organic structure consequences in a lower homocysteine degree. Folic acid and B vitamins are normally found in fruits and green leafy veggies therefore, the degree of homocysteine in the organic structure depends on the individual ‘s diet and familial factors ( Office of Dietary Supplements 2010 ) .
However, so far, there are no surveies that show folic acid addendums cut downing the hazard of coronary artery disease. This is because it would take really long for the consequences to be known and it is besides expensive. Scientists are researching and seeking to happen out precisely how much folic acid or B vitamins are required to cut down homocysteine degrees, but no consequences so far. Ultimately, vitamin Bc and B vitamins addendum can merely cut down hazard of cardiovascular disease in people with low folate consumption. Such as those people populating in less developed states whereby they do non acquire the foods they need ( American Heart Association 2010 ) .
