Cholesterol.
A substance in animal tissue that is an essential component of cell
membranes and nerve fiber insulation. Cholesterol is important for
the metabolism and transport of fatty acids and in the production
of hormones and Vitamin D. Cholesterol is manufactured by the liver,
and is also present in certain foods (e.g., eggs, shellfish). There
are 2 types of cholesterol in the blood, high-density (HDL) and low-density
(LDL) lipoproteins. Very low cholesterol levels may indicate malnutrition.
Low-density lipoprotein (LDL) cholesterol provides cholesterol
for necessary body functions, but in excessive amounts it tends to
accumulate in artery walls; known as "bad" cholesterol. High-density
lipoprotein (HDL) cholesterol, known as the "good" cholesterol;
a high level in the blood is thought to lower the risk of coronary
artery disease
Saturated fat.
Animal meats, butter, whole milk, and
some tropical plant oils, such as palm and coconut, are the main
sources of saturated fat, which is the least healthy type of fat.
Saturated fat raises the level of LDL (bad) cholesterol, which causes
numerous health problems if consumed in large quantities. Most saturated
fats are solid at room temperature.
Unsaturated fat.
Most animal and vegetable fats contain
monounsaturated fat, but in varying quantities. It is usually in
liquid form at room temperature, but it may begin to solidify if
it is chilled. Monounsaturated fat is the most desirable
type of fat in the diet because it helps to decrease the LDL (bad)
cholesterol in the blood and helps to increase the HDL (good) cholesterol.
Good sources of monounsaturated fat are olive oil, canola oil, peanut
oil, and most nuts. Olive oil has the highest percentage (about
77%) of monounsaturated fat of any edible oil.
The main sources of polyunsaturated fats are seeds,
nuts, grains, and vegetables. Polyunsaturated fat is usually
in a liquid state at room temperature and also when chilled. It
lowers the overall cholesterol level, but it also reduces HDL or
good cholesterol. Recommended daily allowances of polyunsaturated
fats should be part of a balanced diet, but some tests have shown
that high consumption may actually be damaging to the digestion
and nervous systems, so moderation is the key for a balanced and
healthy diet.
Trans-fat.
Trans-fatty acid, also known as trans-fat, is formed
when hydrogen is added to vegetable oil in order to change the liquid
oil into a solid at room temperature. This process is known as
hydrogenation, which also transforms the unsaturated fats of
the liquid oils into saturated fat. Like saturated fat, trans-fat
may raise blood cholesterol levels and increase the risk of heart
related diseases. Many shortenings, margarine, and commercially
baked goods are high in trans-fatty acids. Manufacturers will be
required to list trans-fats on the nutrition label, in the meantime
look for the word hydrogenated in the ingredients.
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