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Fats and Cholesterol
Some fats are essential to our health. The reason that fats have a bad name is because saturated fats are a major cause of coronary heart disease along with cholesterol. But this does not mean that all are bad.
What Are Fats?
Fats are also known as lipids. They can be divided into three general categories:
- Triglycerides
- Phospholipids
- Sterols
Triglyceride Fats And Oils
Triglycerides form the main part of fat in most peoples diet. They provide us with energy, insulate, cushion and protect internal organs and help our bodies to use carbohydrates and proteins with more efficiency. The following are types of triglcerides:
Saturated Fats
These are usually solid at room temperature, saturated fat contains the
maximum number of hydrogen atoms (that is "saturated" with hydrogen).
Saturated fats are said to be the least good for your health.
Monounsaturated Fats
The monounsaturated fat includes olive and canola oils. This type of fat lowers
bad LDL cholesterol leaving the good HDL cholesterol the same. They are liquid
at room temperature.
Polyunsaturated Fats
The polyunsaturated fat includes corn oil, safflower oil and sunflower oil. This
type of fat lowers both bad LDL and good HDL cholesterol. They are liquid at
room temperature.
Hydrogenated Fats
This fat results from a process where hydrogen atoms are added back to
polyunsaturated or monounsaturated fats to protect against going bad. This
procedure effectively causes hydrogenated fats to become saturated fats.
Therefore, if a food lists partially hydrogenated oils among its first three
ingredients, it usually contains alot of trans-fatty acids and saturated fats.
Trans-fatty acids
In nature, most unsaturated fats are cis-fatty acids. During hydrogenation, the
molecular structure changes from cis- to trans-fatty acids. Trans-fatty acids
increase bad LDL cholesterol and lower good HDL cholesterol, this in turn may
increase the risk of heart disease.
Essential fatty acids
The body uses essential fatty acids to maintain the structural parts of cell
membranes. They are also used as a component in the production of hormone-like
substances (eicosanoids) that help regulate blood pressure, clot formation, and
maintain the immune response. Essential fatty acids have to be supplied by the diet.
- Linoleic Acid (The Omega-6 family). Common sources for these essential fatty acids are vegetable oils and meats. Most individuals can get an adequate intake of Omega-6 fatty acids by including seeds, grains, leafy vegetables, and small amounts of vegetable oils and meats in the diet.
- Linolenic Acid (The Omega-3 family). Linolenic acid is a major component of the communicating membranes of the brain, it is also active in the eye's retina. It is essential for growth and development. Fish is particularly rich in both Omega-3 and Omega-6 fatty acids.
Phospholipids
The phospholipids help transport fat-soluble vitamins, hormones and other
substances through cell membranes. Because they can dissolve in both water and
fat, they act as an emulsifier, helping to keep fat suspended in body fluids and
blood. The liver can produce all the body's phospholipids itself, so it is not
an essential nutrient. Lecithin is an example of a phospholipid.
Sterols
Sterols include vitamin D, cholesterol, and sex hormones. They are a component
of bile, sex hormones (testosterone), adrenal hormones (cortisol) and are a
structural component of cell membranes. Most of the body's cholesterol is
stored in cells.
Cholesterol
Most cholesterol is manufactured by the liver. It makes about 800-1500 mg. of
cholesterol per day, which contributes much more to total body cholesterol than
diet does. The liver can also make cholesterol from carbohydrates, proteins or
fat. Only animal foods contain cholesterol. Excess cholesterol harms the body
when it forms plaque deposits on artery walls, leading to atherosclerosis and
heart disease. Cholesterol can be further divided into HDLs and LDLs.
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