Profile of Soybean Oil - Dietary Guidelines
for Fat Consumption
Soybeans are low in saturated fat,
and have no cholesterol. Replacing animal protein with soy protein
in the diet has been shown to lower blood cholesterol levels, in
both animals and humans.
Soybean oil is low in saturated fat, rich in the essential fatty acids
and is an excellent source of vitamin E. Like all plant fats, soybean
oil has no cholesterol.
The soybean is the world's leading source of edible oil. It is low in
saturated fat, with a content of about 15%, high in unsaturated fat, with
61% polyunsaturated and 24% monounsaturated fat. Soybean oil is a good
source of both linoleic and linolenic acids, which are essential for humans.
More than 50% of the fat in soy is linoleic acid, while about 7% of the
total fat is linolenic. When soybean oil is hydrogenated, the percentages
of these polyunsaturated fats decrease.
Before processing, soybeans are very high in the fat soluble vitamin
E, as both alpha and gamma tocopherols. Processing removes over 30% of
the vitamin E which then becomes a valuable byproduct used to make vitamin
E supplements. The processed oil is still considered a good source of
vitamin E because one serving (1 teaspoon) provides more than 10% of the
minimum daily requirement. Because soybean oil is a part of so many food
products, it is one of the major sources of vitamin E in the current U.S.
Soy lecithin is another valuable byproduct of soybean oil processing.
Lecithin acts as an emulsifier, making it possible to produce stable blends
of fats and water in foods.
Health authorities agree that excessive fat consumption increases risk
for certain chronic
diseases, including heart disease, some forms of cancer, and diabetes.
Every five years the U.S. government publishes an update of the Dietary
Guidelines for Americans. Both this document and the National Cholesterol
Education Program recommend that no more than 30% of calories in the diet
should come from fat, and no more than 10% of calories from saturated
Consumption of saturated fat beyond the recommended level tends to increase
blood cholesterol levels and the risk of atherosclerosis. Research investigating
the physiological effects of fats is beginning to reveal a much more complicated
picture, in which individual types of fatty acids have different effects.
A great deal of research has been done over the past 40 years on the
effects of dietary fats on serum lipids and lipoproteins. A study involving
seven countries looked at the association between intake of individual
dietary fatty acids and mortality from coronary heart disease. This study
found a significant association between intake of saturated fatty acids
and mortality from heart disease. Further, a meta-analysis of 27 studies
concluded that replacing dietary saturated fat with unsaturated fat lowers
total cholesterol levels, and also improves the ratio of HDL to LDL cholesterol.
This was found to be true even with no change in total fat consumption,
as long as obesity was not present.
Some researchers have found that alpha-linolenic acid, one of the essential
unsaturated fats, may help lower risk of stroke as well. Alpha-linolenic
acid comprises about 7% of the fats in soybean oil, making the oil a fairly
good source of this fatty acid.
Some of the products made from soybean oil go through a hydrogenation
process, which forms trans fatty acids. Hydrogenation is done to promote
stability of the products, or to create a more solid form of fat, such
as shortening or margarine. Small amounts of trans fats are also found
naturally in meat and dairy products.
Story compliments of United
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