Atherosclerosis is the process whereby fatty substances such as cholesterol and calcium form plaque on the inner lining of an artery, causing them to harden. If enough builds up the plaque can reduce blood flow through the artery, and if it ruptures blood clots can form, which can block the flow of blood to the heart and cause a heart attack.
Atherosclerosis occurs naturally in humans as part of the aging process, but certain factors including high blood cholesterol, smoking, high blood pressure, obesity and diabetes increase the risk.
A report last year in the Journal of Nutrition (Vol. 135, pp. 2114-2118) reported that a zinc deficiency in mice was associated with an increase in the risk of cardiovascular disease (CVD) through inflammation and a decreased level of compounds that protect against atherosclerosis.
The new research reports that supplementation of a high cholesterol diet with zinc reduced the formation of lesions in the arteries of rabbits, but the effects were not linked to changes in cholesterol levels.
The National University of Singapore divided 18 white rabbits into three groups. The first was fed a normal diet (control), the second fed a high-cholesterol diet (HCD, one per cent cholesterol), and the third was fed the HCD diet but was supplemented with zinc in the carbonate form (0.1 per cent).
After eight weeks, the researchers measured blood levels of HDL, LDL, and total cholesterol, as well as triglyceride levels. The number of white and red blood cells were also measured.
The researchers found that zinc supplementation did not significantly change total cholesterol, LDL, or triglyceride levels, but a significant decrease in HDL levels was observed – 6.9 millimoles per litre in the HCD group and 2.6 millimoles per litre in the HCD plus zinc group.
This result appears to agree with last years report that zinc deficiency is associated with increased levels of HDL.
When the scientists investigated the formation of lesions in the rabbit aorta. They found that zinc supplementation significantly decreased the area of the lesions by 66 per cent, a result linked to a decrease in iron concentrations in the tissue, which has previously been reported to catalytically promote damaging free-radical reactions and the development of atherosclerosis.
Comment: This study shows that High Cholesterol is not what causes damage to the arteries, but high iron levels that create free radical damage, that zinc apparently removes or modifies so that damage is reduced.
Christopher Wiechert, C.N.C.
Christopher Wiechert's Healthblogger is for educational or informational purposes only, and is not intended to diagnose or provide treatment for any condition. If you have any concerns about your own health, you should always consult with a healthcare professional. If you decide to use this information on your own, it's your constitutional right, but I assume no responsibility.
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