Cholesterol: An Overview

So many of you have e-mailed me with questions about cholesterol and nutrition. I am finally starting to learn more about this topic in class, so I wanted to start sharing some good information.

Most people go to the doctor, get their cholesterol levels checked, and leave with a very basic knowledge of their “good” and “bad” cholesterol levels: too high, too low, or just right. But how many of us actually go home and do further research on what exactly these levels mean and signify about our health?

I am going to provide a basic overview of how cholesterol works inside our bodies. Later this week, I will begin to incorporate some nutrition into the equation. Keep in mind that every individual is different and so many things – such as genes, diet and lifestyle – can factor into cholesterol levels.

Cholesterol is important for our bodies. It is an essential structural component of cell membranes and it manufactures bile acids, steroid hormones, and many fat-soluble vitamins. Within the cell, it is needed for transport and nerve conduction. However, high levels of cholesterol can lead to buildup and thickening of artery walls. This causes difficulties with blood flow and eventually leads to serious heart problems.

LDL stands for low-density lipoproteins, and is the “bad” cholesterol you hear so much about. LDL carries fats and cholesterol from our foods and from our liver to our cells. HDL stands for high-density lipoproteins, and is the “good” cholesterol. HDL carries cholesterol from our cells back to our liver, where cholesterol is changed into bile and excreted into our intestines and then out through our stool. When you see a Total Blood Cholesterol reading, it refers to all cholesterol in transit to and from cells, so both LDL and HDL levels.

According to the medical world, a high HDL (“good”) level (50-75 mg/dl) indicates that excess cholesterol is being properly removed from our blood, which therefore means we are not at risk of cholesterol buildup in the arteries. A high LDL (“bad”) level (above 120mg/dl) may indicate our body is overloaded with cholesterol from either food, internal production of cholesterol, or improper removal of cholesterol. This excess cholesterol is deposited into our arteries and increases risk of cardiovascular disease.

Thought: Is the issue too much cholesterol in the diet, or is it not enough vitamins, minerals and essential fatty acids, which are required to remove excess cholesterol?

Cholesterol comes from two sources: foods or our bodies. Food sources of cholesterol are animal foods: eggs, meat, dairy, fish and shellfish. Plant foods are always cholesterol-free. About half of dietary cholesterol is actually absorbed; the rest is passed through our body unused. The amount of cholesterol produced by the body depends on the amount received from food. If we consume lots of cholesterol, the body makes less; if we have a low-cholesterol diet, the body is forced to make more cholesterol.

Our cells manufacture cholesterol based on need. For example, when we consume alcohol, the alcohol dissolves cell membranes. In response, cells create cholesterol and use it to build the membrane back up. As the alcohol wears off, the membrane hardens, and some of the excess cholesterol binds to essential fatty acids and travels through our blood to the liver, where it is converted to bile and removed from the body through our stools. The liver, intestines, adrenal and sex glands also produce cholesterol for proper functioning.

Thoughts: Lowering alcohol intake may help reduce cholesterol levels because our body will not need to produce cholesterol in response to alcohol’s damage to our cells. Also, essential fatty acids are crucial as they are responsible for removing excess cholesterol from our bodies; a diet low in essential fatty acids may lead to increased blood cholesterol levels.

Unlike carbohydrates, fats and proteins, cholesterol cannot be broken down by the body. It must be removed through our stool in the form of bile acid and cholesterol molecules. Dietary fiber aids in the removal of cholesterol, and without fiber, up to 94% of cholesterol and bile acids are reabsorbed. Therefore, low-fiber diets can lead to increased blood cholesterol levels.

Thought: If you have high cholesterol, perhaps try increasing fiber in your diet as one way to remove cholesterol from your body and lower your overall cholesterol.

Tomorrow I will talk more about nutrition and cholesterol. I have always emphasized balance inside the body, and high cholesterol levels can indicate an imbalance caused by nutrition alone. Since people with heart disease often have cholesterol buildup in their arteries, cholesterol is often identified as the cause of heart disease. However, some believe that lifestyle choices such as high consumption of alcohol, a poor diet, smoking or lack of exercise actually lead to heart disease, and the cholesterol buildup is just one side effect. There are many different theories and it is up to the individual to decide which approach they'd like to take: treatment by drugs, treatment by lifestyle changes, or a combination of both.

Also, please don’t forget to sign up for my cookbook giveaway! You have 3 days left to sign up. Simply go here to see the cookbook (it benefits Haiti!) and leave a comment so you are entered!