How Antioxidants Protects -

How Lipoprotein Become Dangerous?

Cholesterol and other fatty materials (lipids) are transported around in the bloodstream in the form of tiny fatty bodies known as 'lipoproteins'. These are loose chemical combinations of fats and proteins. They come in two main kinds, the low density lipoproteins (LDLs) and the high density lipoproteins(HDLs).The density comes from the proportion of protein present. HDLs have a lot of protein and a little cholesterol; LDLs have a lot of cholesterol and a little protein. LDLs carry cholesterol and other fats from the liver to the tissues including the arteries and HDLs cry cholesterol and fats from the tissues to the liver. You can think of LDLs as the 'baddies' and HDLs as the 'goodies'.

Scientists have known about this for years and have also known that if you eat a lot of saturated fats stable fats with no double bonds between the carbon atoms, that are solid at room temperature you will have lots of LDLs in your blood. If you eat only polyunsaturated fats fats with many double bonds, that are usually liquid at room temperature you will have far fewer LDLs in your blood. What has not been known is how the cholesterol from the LDLs gets into the atherosclerotic plaques.stated that there was strong evidence that free radical oxidation of LDLs was the essential fact and that unless LDLs were oxidized they were not capable of forming plaques. Delegates at the conference were told that the natural antioxidants in the LDLs were depleted by the free radicals to the point where they could no longer prevent damaging chain reactions caused by free radicals.

At the same conference, Dr. K. Fred Gey of Hoffmann-La Roche, Basel, and a professor at the Institiute of Biochemistry and Molecular Biology, University fo Berne, reported the results of an interesting survey. This study, co-sponsored by the World Health Organization, investigated the reasons for the striking differences in the mortality, in different countries, from heart disease caused by atherosclerosis of the coronary arteries. It had involved 11,000 men aged 40 to 59 years from 12 countries. In some countries, the death rates from heart disease was much higher than in others. Men living in Scotland and Finland, for instance, were four times as likely to die from heart disease as men living in Italy or Switzerland. There must clearly be some explanation for this remarkable difference, and Dr. Gey suggested that it might have been found.

In the course of the survey, the levels of antioxidant vitamin E in the blood of the subjects was monitored over a four month period. The results were remarkably suggestive. In those with low levels of this vitamin, the death rates were significantly higher than in those with higher levels. This was not a marginal difference. Studies of previous risk factors, such as smoking, high blood pressure and high blood cholesterol, could predict an increased risk of heart disease with an accuracy of only 50%. When the blood levels of thee vitamins were also taken into account, the accuracy rose to 94%.It is probably worth mentioning, in this context, the fact reported in the Scottish Medical Journal in 1989 that middle aged Scottish men eat very little fruit and green vegetables. Can this be a pure coincidence?

In 1991, the prestigious weekly journal the Lancet, carried a leading article a report produced by the heart research unit in the Department of Cardiology and Medicine of the University of Edinburgh. This report, by Dr. R.A. Riemersma and colleagues, described a research study into whether there was any connection between the levels of certain vitamins in the body and the risk of having angina pectoris. The vitamins concerned were vitamin C, E and A and the substance beta-carotene that is converted by the liver into vitamin A. there was more to this trail than immediately meets the eye.