Thursday, December 1, 2011

Dietary sources

Animal fats are complex mixtures of triglycerides, with lesser amounts of phospholipids and cholesterol. As a consequence, all foods containing animal fat contain cholesterol to varying extents. Major dietary sources of cholesterol include cheese, egg yolks, beef, pork,poultry, fish, and shrimp.
Human breast milk also contains significant quantities of cholesterol.
From a dietary perspective, cholesterol is not found in significant amounts in plant sources. In addition, plant products such as flax seeds and peanuts contain cholesterol-like compounds called phytosterols, which are believed to compete with cholesterol for absorption in the intestines. Phytosterols can be supplemented through the use of phytosterol containing functional foods or nutraceuticals which are widely recognized as having a proven LDL cholesterol lowering efficacy. Current supplemental guidelines recommend doses of phytosterols in the 1.6-3.0 grams per day range (Health Canada, EFSA, ATP III,FDA) with a recent meta-analysis demonstrating an 8.8% reduction in LDL-cholesterol at a mean dose of 2.15 gram per day. However, the benefits of a diet supplemented with phytosterol has been questioned.
Total fat intake, especially saturated fat and trans fat, plays a larger role in blood cholesterol than intake of cholesterol itself. Saturated fat is present in full fat dairy products, animal fats, several types of oil and chocolate. Trans fats are typically derived from the partial hydrogenation of unsaturated fats, and do not occur in significant amounts in nature. Trans fat is most often encountered in margarine and hydrogenated vegetable fat, and consequently in many fast foods, snack foods, and fried or baked goods.
A change in diet in addition to other lifestyle modifications may help reduce blood cholesterol. Avoiding animal products may decrease the cholesterol levels in the body not only by reducing the quantity of cholesterol consumed but also by reducing the quantity of cholesterol synthesized. Those wishing to reduce their cholesterol through a change in diet should aim to consume less than 7% of their daily energy needs {metric units Joules (J) or (kJ), pre-SI calories (Cal) or (kcal)} from animal fat and fewer than 200 mg of cholesterol per day.
It is debatable that a diet, changed to reduce dietary fat and cholesterol, can lower blood cholesterol levels, (and thus reduce the likelihood of development of, among others, coronary artery disease leading to coronary heart disease), because any reduction to dietary cholesterol intake could be counteracted by the organs compensating to try to keep blood cholesterol levels constant. Also pointed out is the experimental discovery that in the diet, ingested animal protein can raise blood cholesterol more than the ingested saturated fat or any cholesterol.

Resource: Wiki

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