Dietary fibers cholesterol

Molecular Interactions. Various polysaccharides readily associate with other substances, including bile acids and cholesterol, proteins, small organic molecules, inorganic salts, and ions. Anionic polysaccharides form salts and chelate complexes with cations some neutral polysaccharides form complexes with inorganic salts and some interactions are stmcture specific. Starch amylose and the linear branches of amylopectin form inclusion complexes with several classes of polar molecules, including fatty acids, glycerides, alcohols, esters, ketones, and iodine/iodide. The absorbed molecule occupies the cavity of the amylose helix, which has the capacity to expand somewhat to accommodate larger molecules. The starch—Hpid complex is important in food systems. Whether similar inclusion complexes can form with any of the dietary fiber components is not known. 

BROWN L, ROSNER B, wiLLET w w, SACKS F M (1999) Cholesterol-loweiing effeects of dietary fiber a meta-analysis, American Journal of Clinical Nutrition, 69, 30-42. 

Therapeutic lifestyle changes should be the first approach tried in all patients (Table 9—7).3 An adequate trial of TLC should be employed in all patients, but pharmacotherapy should be instituted concurrently in higher-risk patients. This includes dietary restrictions of cholesterol and saturated fats as well as regular exercise and weight reduction. In addition, therapeutic options to enhance LDL cholesterol lowering such as consumption of plant stanols/sterols (which competitively inhibit incorporation of cholesterol into micelles) and dietary fiber should be encouraged. These therapeutic options collectively may reduce LDL cholesterol by 20% to 25%. 

Martin-Carron N, Goni I, Larrauri JA, Garcia-Alonso A and Saura-Calixto F. 1999. Reduction in serum total and LDL cholesterol concentrations by a dietary fiber and polyphenol-rich grape products in hypercholesterolemic rats. Nutr Res 19 1371-1381. 

Leontowicz M, Gorinstein S, Bartnikowska E, Leontowicz H, Kulasek G and Trakhtenberg S. 2001. Sugar beet pulp and apple pomace dietary fibers improve lipid metabolism in rats fed cholesterol. Food Chem... 

Monounsaturated fat Carbohydrates Cholesterol Dietary fiber Plant sterols Protein Total calories... 

In the studies discussed, wheat bran, cellulose, and psyllium fiber feeding resulted in increased fecal fat losses and in lowered blood serum cholesterol and triglyceride levels (14,15,32,41) as well as increased fecal losses of calcium. Possible involvement of dietary fat with high or low dietary fiber intake has not been extensively investigated. However, that calcium is involved in intestinal fat absorption is generally accepted (42-45). 

These results apparently support those in the previous study however, because dietary fiber was higher in the low fat diet than in the high fat diet, it is impossible to separate the effects of fat, fiber and possibly cholesterol. The alterations used in the low fat, controlled diet were essentially those recommended in the U.S. Dietary Goals/Guidelines while the moderately high fat, self-selected diets resembled usual American dietary intake patterns. 

Anderson, J. W., Jones, A. E., and Riddell-Mason, S. (1994). Ten different dietary fibers have significantly different effects on serum and liver lipids of cholesterol-fed rats. /. Nutr. 124, 78-83. 

Arjmandi, B. H., Craig, J., Nathani, S., and Reeves, R. D. (1992). Soluble dietary fiber and cholesterol influence in vivo hepatic and intestinal cholesterol biosynthesis in rats. /. Nutr. 122,1559-1565. 

Brown, L., Rosner, B., Willett, W. W., and Sack, F. M. (1999). Cholesterol-lowering effects of dietary fiber A meta-analysis. Am. J. Clin. Nutr. 69, 30-42. 

Sea animals are rich in soluble dietary fibers, proteins, minerals, vitamins, antioxidants, phytochemicals, and polyunsaturated fatty acids, with low caloric value. Polysaccharides from marine animals have been reported to possess biological activities with potential medicinal values in addition to their current status as a source of dietary fibers and prebiotics. Moreover, they have a lot of dietary fiber, which lowers blood cholesterol, and iodine, which improves metabolism, vascular and cardiac action, body temperature, and perspiration regulation, and are effective in... 

Bile salts secreted into the intestine are efficiently reabsorbed (greater than 95 percent) and reused. The mixture of primary and secondary bile acids and bile salts is absorbed primarily in the ileum. They are actively transported from the intestinal mucosal cells into the portal blood, and are efficiently removed by the liver parenchymal cells. [Note Bile acids are hydrophobic and require a carrier in the portal blood. Albumin carries them in a noncovalent complex, just as it transports fatty acids in blood (see p. 179).] The liver converts both primary and secondary bile acids into bile salts by conjugation with glycine or taurine, and secretes them into the bile. The continuous process of secretion of bile salts into the bile, their passage through the duodenum where some are converted to bile acids, and their subsequent return to the liver as a mixture of bile acids and salts is termed the enterohepatic circulation (see Figure 18.11). Between 15 and 30 g of bile salts are secreted from the liver into the duodenum each day, yet only about 0.5 g is lost daily in the feces. Approximately 0.5 g per day is synthesized from cholesterol in the liver to replace the lost bile acids. Bile acid sequestrants, such as cholestyramine,2 bind bile acids in the gut, prevent their reabsorption, and so promote their excretion. They are used in the treatment of hypercholesterolemia because the removal of bile acids relieves the inhibition on bile acid synthesis in the liver, thereby diverting additional cholesterol into that pathway. [Note Dietary fiber also binds bile acids and increases their excretion.]... 

Dietary fiber has a pronounced effect on the characteristics of the fecal mass and on the rate of passage of digest through the G1 trad, High fiber diets also play a role in the excretion of bile acids and cholesterol. 

As previously mentioned, flaxseed is a rich source of dietary fiber (28%). Dietary fiber has been widely viewed as a component essential to lowering the risk of colon cancer. The flaxseed protein is similar to soy thus may be beneficial to health. Bhathena et al. (2002) first reported that flaxseed protein was effective in lowering plasma cholesterol and triacylglycerides (TAG) compared to soy and casein protein in male F344 and obese SHR/N-cp rats. The role of protein in disease prevention warrants further investigation. Components, such as PAs and flavonoids, may also contribute to the health benefits of flaxseed. 

Ebihara, K. and Schneeman, B.O. 1989. Interaction of bile acids, phospholipids, cholesterol and triglyceride with dietary fibers in the small intestine of rats. J. Nutr. 119, 1100-1106. 

Ikeda, I., Tomari, Y., and Sugano, M. 1989b. Interrelated effects of dietary fiber and fat on lymphatic cholesterol and triglyceride absorption in rats. J. Nutr. 119, 1383-1387. 

Mathe, D., Lutton, C., Rautureau, J., Coste, T., Gouffier, E., Sulpice, J.C., and Chevallier, F. 1977. Effects of dietary fiber and salt mixtures on the cholesterol metabolism of rats. J. Nutr. 107, 466-474. 

Vahouny, G.V., Tombes, R., Cassidy, M.M., Kritchevsky, D., and Gallo, L.L. 1980. Dietary fibers. V. Binding of bile salts, phospholipids and cholesterol from mixed micelles by bile acid sequestrants and dietary fibers. Lipids 15, 1012-1018. 

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