Cholesterol levels

The Problem. Suppose that the total serum cholesterol level in normal adults has been established as 200mg/100mL (mg%) with a standard deviation of 25 mg%, that is, p = 200 and ct = 25. (Please distinguish between mg% and % probability.) A patient s serum is analyzed for cholesterol and found to contain 265 mg% total cholesterol. 

The intermediate m hydrogenation formed by reaction of the unsaturated ester with the hydrogenated surface of the metal catalyst not only can proceed to the saturated fatty acid ester but also can dissociate to the original ester having a cis double bond or to its trans stereoisomer Unlike polyunsaturated vegetable oils which tend to reduce serum cholesterol levels the trans fats produced by partial hydrogenation have cholesterol raising effects similar to those of saturated fats... 

One frozen dessert is made with Simplesse, a protein-based fat mimetic that contains no fat (37). Other dairy product developments include a fat flavor, produced by encapsulating milk fatty acids in maltodextrins (38) fat-free cottage cheeses and 2% fat milk, prepared by steam stripping cream with partial fat addback, with a cholesterol level about 60% lower than the starting material (39). 

Saponins dismpt red blood cells and may produce diarrhea and vomiting. They may also have a beneficial effect by complexing with cholesterol [57-88-5] and thus lowering semm cholesterol levels (24,25). In humans, intestinal microflora seem to either destroy saponins or inactivate them in small concentrations. 

The possibility that vitamins might have physiological functions beyond the prevention of deficiency diseases was first recognized in 1955 with the finding (8) that niacin can affect semm cholesterol levels in humans. An explosion of research (9—11) in the intervening years has been aimed at estabUshing optimal vitamin levels and anticipating the health consequences. 

Brewers and bakers dried yeasts are used as dietary supplements. They contribute some protein and trace minerals, and some B vitamins, but no vitamin C, vitamin B 2 or fat-soluble vitamins. The glucose tolerance factor (GTE) of yeast, chromium nicotinate, mediates the effect of insulin. It seems to be important for older persons who caimot synthesize GTE from inorganic dietary chromium. The ceU wall fraction of bakers yeast reduces cholesterol levels in rats fed a hypercholesteremic diet. 

Bile Acid Sequestrants. The bile acid binding resins, colestipol [26658424] and cholestyramine, ate also effective in controlling semm cholesterol levels (150). Cholestyramine, a polymer having mol wt > ICf, is an anion-exchange resin. It is not absorbed in the gastrointestinal tract, is not affected by digestive enzymes, and is taken orally after being suspended in water (151). 

Thus, it is apparent that soya, some soya products and linseed oil influence blood lipid levels, particularly cholesterol and LDL cholesterol. While the extent of the reduction appears to largely depend on an individual s initial serum cholesterol level, the maximum reductions observed are of the order of 10-15%. For hyperlipidemic individuals this may not be a marked reduction, but such an effect on the general population may well have a beneficial effect on the overall incidence of cardiovascular disease and atherosclerosis. The possibility that non-phytoestrogenic dietary components may contribute to the hypocholes-terolemic properties cannot, however, be discounted. Indeed, certain types of dietary fibre have been shown to have a hypolipidemic effect via their ability to increase faecal excretion rates. 

Degradation of HMG-CoA reductase. This enzyme has a half-life of only three hours, and the half-life itself depends on cholesterol levels high [cholesterol] means a short half-life for HMG-CoA reductase. 

Gene expression—cholesterol levels control the amount of mRNA. If [cholesterol] is high, levels of mRNA coding for the reductase are reduced. If [cholesterol] is low, more mRNA is made. (Regulation of gene expression is discussed in Chapter 31.)... 

Derivatives of lovastatin have been found to be even more potent in cholesterol-lowering trials. Synvinolin lowers serum cholesterol levels at much lower doses than lovastatin. 

It s hard to resist, but a high intake of saturated animal fat doesn t do much for your cholesterol level. 

We hear a lot these days about the relationships between saturated fats, cholesterol, and heart disease. What are the facts It s well established that a diet rich in saturated animal fats often leads to an increase in blood serum cholesterol, particularly in sedentary, overweight people. Conversely, a diet-lower in saturated fats and higher in polyunsaturated fats leads to a lower serum cholesterol level. Studies have shown that a serum cholesterol level greater than 240 mg/dL (a desirable value is <200 mg/dL) is correlated with an increased incidence of coronary artery disease, in which cholesterol deposits build up on the inner walls of coronary arteries, blocking the flow of blood to the heart muscles. 

Cold-water frsh like salmon are rich in omega-3 fatty acids, which have a double bond three carbons in from the noncarboxyl end of the chain and have been shown to lower blood cholesterol levels. Draw the structure of 5,8,11,14,17-eicosapentaenoic acid, a common example. (Eicosane = C20H42)... 

Medicinal chemistry has frequently drawn inspiration and important new leads from the examination of natural products, and this was proven to be the case once more. In 1992, researchers at Merck and Glaxo announced, almost simultaneously, the independent discovery of the same new class of natural products from two different fungi. As a consequence, the same family of natural products has two names - the zaragozic acids (Merck)4 or the squalestatins (Glaxo).5 A typical member of the family, zaragozic acid A (squa-lestatin SI) (1) was shown to have a tremendous affinity for squalene synthase (K, = 79 pM for rat microsomal squalene synthase) and could even lower serum cholesterol levels in vivo in a population of marmosets.6... 

Statins lower plasma cholesterol levels by inhibiting HMG-CoA reductase in the mevalonate pathway (Fig. 4). Some research has shown that certain statins (but not all) stimulate BMP-2 expression in osteoblasts, increase bone formation and mimic N-BP in that they inhibit bone resorption. The use of statins in osteoporosis is presently being investigated. 

Rate-limiting enzyme in cholesterol biosynthesis inhibition by statins results in reduction of plasma LDL-cholesterol levels. 

Statins may reduce total cholesterol and LDL-cholesterol levels in plasma by 50-60%, reduce plasma... 

Contain potential benefits for men in protection against age-related bone loss and increases in cholesterol levels, without displaying estrogenic proliferative effects in the prostate... 

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