Lipoproteins

There are four major types of lipoproteins. They all contain protein, triglycerides, phospholipids and cholesterol all in different proportions. Their function is to transport lipids and those that have a higher amount of protein in them, have a higher density. You will see while reading on why LDL cholesterol is known as bad cholesterol while HDL is known as good cholesterol.

Chylomicrons are the highest concentration of triglycerides. They are dietary lipids or fats. They enter the lymphatic circulation and then the bloodstream. Their peak lipid blood levels after a meal is 30 minutes to 3 hours and is cleared after 14 hours. They contain so little protein and so much triglyceride that they are the lowest in density.

Very Low Density Lipoproteins (VLDL) are made in the liver. They have a high concentration of triglycerides. High levels of VLDLs are associated with obesity, diabetes, ethanol, high fat diets, refined carbohydrates and sugars. As VLDLs remove triglycerides and pick up cholesterol they become LDLs. They are half triglycerides accounting for their low density.

Low Density Lipoproteins (LDL) are made from VLDLs. They contain a high concentration of cholesterol and a small amount of them are associated with heart disease. Apo-B is bound to a small, very dense protein called apolipoprotein B that plays a major role in cardiovascular disease. Apo-B particles enable cholesterol to penetrate and lodge in vascular walls to form athersclerotic plaque. The link between apo-B and cardiovascular disease measuring these levels gives clinicians and patients a new and highly specific marker for assessing both the precise level of LDL and determining the risk for developing cardiovascular disease. LDL is taken up in lesions in endothelial cells lining the inner walls of blood vessels, forming deposits in the arterial walls. Next the LDL undergoes modification as free radicals oxidizing the LDL to form foam cells that form a thick, hard plaque. They are half cholesterol which is why they are associated with heart disease. So it is important to stay away from VLDL and LDL cholesterol.

High Density Lipoproteins (HDL) removes cholesterol from cells and other lipoproteins to be broken down by the liver. Cholesterol is excreted in the bile. High HDLs are associated with health, longetivity and low risk of Cardiovascular disease. Low HDLs are associated with obesity and diabetes. They are half protein which is why they are high density. So HDL’s are known as the “good” cholesterol and LDLs are known as “bad” cholesterol.

Choose Fats Wisely:

Limit your cholesterol, trans fats and saturated fats

  • When selecting meats, choose rounds and loins– they are lower fat cuts of meat
  • Opt for chicken and fish– don’t eat the skin
  • Try a vegetarian meal once a week– beans and other vegetarian sources of protein are low in trans and saturated fats and don’t contain cholesterol
  • Use low fat milk, yogurt and cheese
  • Choose margarine with no trans fat
  • Cut down on packaged foods that contain trans fats

Increase mono and polyunsaturated fats

  • Choose olive, peanut, or canola oil for cooking and salad dressing
  • Use corn, sunflower or safflower oil for baking
  • Snack on nuts and seeds
  • Add olives, avocados, nuts and seeds to salads

Get enough omega-3’s

  • Sprinkle flaxseed on your cereal or yogurt or bake it into muffins
  • Add another serving of fish to your weekly menu
  • Have a leafy green vegetable with dinner
  • Put walnuts in your salad

Watch your total fat

  • Instead of frying: bake, broil, barbeque, roast, steam or microwave
  • Have a smaller serving of ice cream
  • Try oven-fried rather than deep-fried potatoes
  • Use half your usual amount of butter

Live a healthy lifestyle by choosing these options as well as keeping in mind that diet and exercise work together to achieve your optimal goal!!

Source: Thompson, Janice, Melinda Manore, and Linda A. Vaughan. The Science of Nutrition. San Francisco, CA: Pearson Benjamin Cummings, 2011. Print.


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