Alright. The next time you're about to order that double cheese burger from the cafeteria, maybe you should instead do a double take on what you're actually about to consume. Sure it's a mouthwatering hunk of meat with gooey cheese, but it's also chalked full with cholesterol...and not the good kind.
But wait!, you say. There's such thing as a good kind of cholesterol? So settle the confusion, here's what you need to know about the good, the bad, and the ugly [cholesterol].
Cholesterol is a type of fat or lipid. If you've ever tried mixing cooking oil with water, you would know they don't mix. The same goes for cholesterol in the blood, which is why it needs to be associated with proteins to be able to be transported.
This association of a lipid and a protein forms what is called a lipoprotein, which in the body, are classified into several types according to their density.
Did You Know?
Cholesterol is found in different lipoproteins in your body. "Bad" cholesterol is found in low density lipoproteins (LDL) while "good" cholesterol is found in high density lipoproteins (HDL). The Good
HDL is "good" because it takes cholesterol AWAY from your tissues and to the liver to be excreted in your bile and feces. Unfortunately, not all of us are lucky enough to have lots of HDL. In fact, HDL levels vary widely across the human population and even though exercise helps to increase HDL levels, as much as 70% of it is genetically determined. Finally! Something you can blame your parents for!
Did You Know?
Your body makes about 80% of your cholesterol in the liver. Cholesterol is also good because it performs in a lot of normal biological functions: It's an important part of cell membranes and is required for the proper functioning of many proteins. Cholesterol is also used in producing hormones that function during puberty, like packing pounds on the hips (sorry girls), embarrassingly squeaky vocal moments (sorry guys), and inappropriate fantasies about Kristin Kreuk/Orlando Bloom.
The Bad...and the Ugly
LDL is "bad" because it delivers cholesterol from your liver TO your tissues. If your tissues don't take up all the LDL from your blood, the LDL starts sticking to the walls of your blood vessels to form plaques, leading to narrowing of the arteries.
Over time, this can cause decreased blood flow and a condition called atherosclerosis. This can put you at risk for, and here's the ugly part, gangrene, strokes and heart attacks, just to name a few!
How Can You Lower Your Cholesterol?
In order to prevent these nasty health problems later on in life, it's a good idea to limit your cholesterol intake now. Cholesterol can be found naturally in food products derived from animals, such as egg yolks, shrimp, meat, milk products, and butter.
Saturated and trans fats though are the culprits when it comes to promoting cholesterol synthesis. Consuming trans fats is actually a double whammy to your body because it raises your bad cholesterol AND lowers your good cholesterol. Examples of food with saturated and trans fats are: Commercial baked goods, chocolate, butter, ice cream, deli meats, fried or breaded foods, and meat and chicken fat.
It may seem like cholesterol only comes from animals, but this is a common misconception.
Did You Know?
Plants contain a type of cholesterol called phytosterol that is good for you. Phytosterols are like cholesterol but with some very minor chemical differences. However, these differences are enough for phytosterols to inhibit cholesterol absorption from the food you eat and slow LDL formation.
Phytosterols can be found in seeds, soybeans, wheat germ, rice bran, corn oil, peanuts, and hydrogenated margarine. Eating these plant-based products is a good way to lower your bad cholesterol, but be sure to eat lots of vegetables and fruits because too much phytosterol can limit vitamin absorption from your diet.
Finally, for you overachievers who want to take it one step further, exercise is a great way to increase your good cholesterol. Still confused about cholesterol? Don't worry, scientists have been scratching their heads over this subject for decades.
The American Heart Association on cholesterol
Diabetes Quebec on High Cholesterol
Wikipedia on cholesterol
Hui, David Y. and Howles, Philip N. 2005. "Molecular mechanisms of cholesterol absorption and transport in the intestine." Seminars in Cell & Developmental Biology 16: 183-192.
Plat, Jogchum and Mensink, Ronald P. 2005. "Plant Stanol and Sterol Esters in the Control of Blood Cholesterol Levels: Mechanism and Safety Aspects." American Journal of Cardiology 96(suppl):15D-22D.
Rader. Daniel J. 2006. "Molecular Regulation of HDL Metabolism and Function: Implications for Novel Therapies." Journal of Clinical Investigation 116(12):3090-3100.
Joanne Hsieh is a Ph.D. candidate in the Department of Biochemistry at the University of Toronto. Her research is on matters of the heart (actually, it’s the link between diabetes and cardiovascular disease). She’s been going out with her boyfriend for the past 3 years and thought the research for this article would help her move the relationship along.