23 Jun CHOLESTEROL: THE GOOD, THE BAD and THE UGLY
The word cholesterol has become a common buzzword in our current society. Before we disclose to our friends or coworkers the results of our recent cholesterol testing, let’s first take a closer look at this buzzword. As we well know, cholesterol is made up of HDL (high-density lipoprotein), LDL (low-density lipoprotein) and several other types of lipoproteins. We will only spend time on the HDL and LDL types of lipoproteins. An analogy I like to use to explain LDL describes this lipoprotein as kids in high school. As the day progresses, the kids (LDL) use the hallways (blood vessels) and classrooms (peripheral cells) and typically leave trash (cholesterol and other lipids) behind. It’s the janitor’s (HDL) job to remove the mess (lipoproteins and unesterified cholesterol) and return it to the waste disposal unit/recycling plant (liver). It makes sense that if the ratio of LDL is too high compared to HDL, that there are not enough “janitors” to keep up with the “school kids.” Following its return to the liver, free cholesterol is excreted in the bile as bile salts. This is the primary system our body uses to excrete cholesterol out of the body. Based on the above information, cholesterol has been coined as “good and bad cholesterol” by the media, but they are both necessary in human metabolism and therefore should not be labeled either way.
Poor information and media involvement has led to the belief that dietary cholesterol (food sources of cholesterol) is responsible for serum cholesterol levels. In actuality, a change in the amount of cholesterol in the diet has a minimal effect on serum levels, because the body compensates by eliminating more or less based on the level of consumption. The true culprit, guilty of raising LDL levels and lowering HDL levels, is saturated fatty acids (saturated fat is solid at room temperature). Mono and
polyunsaturated fats, e.g., canola oil, olive oil, natural peanut butter, etc. actually lower LDL levels without affecting HDL levels. There is a relatively new enemy called trans fatty acids (TFA) in the grocery stores that has gained a lot of media coverage. Most natural fats are made up of cis double bonds, which the body is prepared to deal with. Trans fatty acids are in a trans configuration (the bond is turned a different direction) and are typically man made by adding hydrogen to polyunsaturated fatty acids. The process is known as hydgrogenation and can be found listed in the ingredients as partially hydrogenated oil. Unfortunately, several studies have shown that TFA’s are capable of raising LDL levels and lowering HDL levels.
The major cardiovascular risk associated with a poor cholesterol ratio is atherosclerosis. To continue the previous analogy, the accumulation of “trash” the “school kids” leave in the hallway accumulates and eventually occludes the hallway making it impassible. We know this accumulation as fatty plaque. What can we do to keep our cholesterol ratios in a healthy range? This is actually not too difficult… you’re here reading this, so you already have the regular exercise aspect down. The next step is to minimize the amount of saturated fat from animal products (fatty meats) in the diet and the last step is to include more MUFA and PUFA (unsaturated) oils in the diet. A few good examples include fatty fish, olive oil, canola oil, safflower oil, flax seed oil and natural peanut butter. Some individuals tend to have poor cholesterol ratios no matter how healthy their diet. These individuals should discuss with their doctor what other avenues are available to maintain healthy ratios.