Symptoms, Causes, Process of Atherosclerosis:

Symptoms [14, 15, 24]

Causes [1, 14, 15]

Process

Left to right= least advanced to most advanced atherosclerosis of the aorta (lipid streaks-plaques-calcification/ulceration)

Four Autopsies of aorta segments showing different degrees of atherosclerosis:

*Autopsy images taken from Nagasaki University (1989)

Courtesy of Professor C.T Hsu, Nagasaki University

Meaning, Advantages, Disadvantages of Oxidation in human body: [1, 5, 7, 22]

Possible ways of maintaining a healthy level of Free Radicals:

Increasing the level of high density lipoprotein will remove accumulated unhealthy cholesterol found in the endothelium and deposit it into the liver. HDLs can prevent the LDL oxidation process and they have some antioxidant capacities. The level of HDL in the body is extremely important; with a low concentration of HDL, LDL will accumulate and the risk for oxidation will increase thus leading to possible heart attacks as a result of atherosclerosis and plaque formation [6].

Keeping a low level of triglycerides in the body can also be beneficial. Diabetes, obesity and insulin resistance are known to be causes of high triglyceride concentrations. When triglyceride levels in the body increase, the HDL concentration will in turn, decrease. With a low level of HDL in the blood, LDL collects within the inner walls of arteries [6].

Another way to maintain a healthy level of free radical concentration is to have a high concentration of antioxidants in the body. Some antioxidants are synthesized in the body while others can be found in foods. Antioxidants are capable of neutralizing free radicals because they can easily give up electrons and convert themselves into a stable form. Once the free radicals do not have unpaired electrons in their valence shells they will no longer be free radicals [17]. 

Guide Listing High Capacity Antioxidants:

(all antioxidant capacity measures are estimated by Ferric Reducing Power and are expressed as mcirocole Trolox exuivalent (TE) per 100 grams or 3.53 ounces, accurate to +/- 5%. )

Oxygen Radical Absorbance Capacity (ORAC) measures the antioxidant capacities of common foods; this method was created by the National Institute on Aging in the National Institutes of Health in Bethesda, Maryland. This method involves measuring fluorescent molecule mixed with free radical generators (ex. Azo-initiator compounds producing peroxyl free radicals). By adding different antioxidants to this substance, the degree of protection done by the particular antioxidant is recorded and compared with other antioxidant levels [21].

*chart is directly taken from: http://www.chocolate-news.org/links_hcs_articles.html

Experiments done on cardiac patients using high capacity antioxidants-- proving my hypothesis

Because I have done a study research project, to prove my hypothesis, my data consists of experiments (from least to most recent) that have been done by other researchers. With these lab results I will prove that with higher antioxidant levels in the body, there is a possibility of reducing the risk of getting atherosclerosis. Also I will prove that the combination of vitamins provides significant benefits to atherosclerosis. 

'LDL Oxidation and Antioxidized LDL in Dialysis Patients' -year 'unspecified' [20]

In this experiment, a comparison of the LDL oxidation process was made between thirteen uremic patients on chronic peritoneal dialysis (PD), 70 control subjects, 10 uremic patients on predialytic conservative therapy, and 11 uremic subjects on repetitive hemodialysis. It is extremely common for patients undergoing these treatments to suffer from atherosclerosis lesions. An evaluation of plasma lipid profile was made as well as a measurement of LDL oxidation and antioxidized LDL antibodies; the antioxidant agent vitamin E level was also measured. To conclude, they found that PD patients showed short termed improvements by a decrease in LDL oxidation. For significant improvements however, PD patients must at the same time, intake vitamin E supplements. Together with the short term benefits of the PD treatment, vitamin E can perhaps reduce the risk of the LDL oxidation process. 

 'The Cambridge Heart Antioxidant Study' (CHAOS) - year 1996 [19]

In this study involving 2002 patients with atherosclerosis, researchers found that after one year of alpha-tocopherol treatment (which is a form of vitamin E), the rate of non-fatal myocardial infarction (heart attack caused by plaque ruptures or thrombus) reduced significantly. Patients were given 400 or 800 IU/d of alpha-tocopherol or they were given placebo. The concentrations of vitamin E (alpha-tocopherol) increased in patients who were given this supplement and stayed the same in patients who were given placebo. As a result, the antioxidant proved to be efficient in this study.   

 'Antioxidant Supplementation in Atherosclerosis Prevention (ASAP)' -year 2000 [23]

In a three year period, 520 human subjects including smokers/ non-smokers, men and women (post menopausal) took a combination of 250 mg of vitamin C and  91mg of d-α-tocopherol (which is vitamin E) two times a day. The purpose of this study was to determine if the combination between vitamin C and d-α-tocopherol would benefit and slow down the progressive cardiovascular disease of arthrosclerosis. Their results proved that for men, the combination of vitamin E and a 'slow-release' of vitamin C slows down the thickening walls of arteries. 

'Clinical Study: Antioxidant vitamins and the risk of carotid atherosclerosis' - year 2001 [16]

This was a one year clinical study done in Australia investigating whether or not antioxidant vitamins were associated with carotid artery intima-media thickness (IMT which measures the thickness of arterial walls) or plaque formation. Measurements of vitamin intake and fasting plasma levels of vitamins A, C, and E, lycopene, and alpha- and beta- carotene and bilateral carotid artery B-mode ultrasound imaging were done on 1,111 human subjects (558 men, 553 women, ages 27-77) with a history of vascular disease in Perth, Western Australia. They found that in men, with a gradual increase in the intake of vitamin E, the average IMT decreased. There were no significant changes however, in the other supplements that they measured for. Although they did find benefits of vitamin E for men, it was not a very significant retardation of plaque accumulation.

^* In the intima-media thickness (IMT) comparisons, the factors adjusted for were age, systolic blood pressure, low density lipoprotein cholesterol, smoking, homocysteine, diabetes, family history and total energy intake. Data are presented as the mean value ± SEM.

Table is directly taken from: http://content.onlinejacc.org/cgi/content/full/38/7/1788/T3

'Garlic Increase Antioxidant Levels in Diabetic and Hypertensive Rats Determined by a Modified Peroxidase Method - year 2009 [18]

In this experimental study, five hypertensive Sprague-Dawley rats were induced with 500mg/kg of garlic extracts (garlic contains antithrombotic, antibiotic, hypolipidemic, hypocholesteremic, hypoglycemic and hypotensive activities), which has a significant level of antioxidant capacity, for three weeks; at the same time, five other hypertensive rats acted as control and were given saline for three weeks. After three weeks, the five rats that were given garlic had an increase in antioxidant levels as well as a 50% decrease in blood pressure. The control rats however, had a decrease in antioxidant levels. 

*images are directly taken from (respectively): <http://www.helpfulhealthtips.com/Images/A/Atherosclerosis.jpg>, <http://www.healthcentral.com/common/images/1/18077_6972_5.jpg>,<http://scienceblogs.com/denialism/2007/11/ask_a_scienceblogger_which_par.php>, <http://newsimg.bbc.co.uk/media/images/41078000/jpg/_41078897_ves4.jpg>, <http://www.scielo.br/img/fbpe/abc/v72n1/a02tab02.gif>,

Back to: Virtual Science Fair - Expo-sciences virtuelle                             Creator: Janine Hsu