Recently a colleague shared with me his frustration over his many failed attempts to reduce his blood cholesterol, which included restricting his intake of saturated fats and foods known to contain dietary cholesterol. He was beginning to feel as if he should eliminate all fat from his diet to avoid chronic diseases such as heart disease, stroke, and diabetes.

I've stressed before the importance of reducing fat in our diets. Just as it's important to balance the amount of calories consumed with the energy you burn during exercise and other activities, it's also important to balance your fat intake. Fat is an important nutrient in our diet and helps maintain many of our normal body functions. Without some fat in our diets the body cannot make all its necessary repairs and deficiencies of the fat-soluble vitamins A, D, E, and K can develop. The role that vitamin D has in helping to prevent osteoporosis by assisting with calcium absorption is just one example of why fat is important in our diets. 

It's also important to understand the relationship between dietary cholesterol and blood cholesterol. In some people, like my colleague, reducing saturated fat and dietary cholesterol will only go so far because they are genetically programmed to produce higher-than-normal levels of cholesterol and other fats. In this case, the only way to solve the problem may be to take cholesterol-lowering medication.

If you are worried about elevated cholesterol or other lipids, the following nutrition information may help you identify its source in the various types of fats in food:

Saturated Fats: These fats are usually solid at room temperature and can raise blood cholesterol levels. Sources include:

• meats, especially organ and processed meats (liver, hot dogs, cold cuts); beef; pork; chicken, especially with skin
• whole-fat dairy products, including whole milk, regular yogurt, hard cheese, ice cream, butter, cream, sour cream, and cream cheese
• coconut, palm, and palm kernel oils, chocolate, and cocoa butter

Monounsaturated Fats: These fats are usually liquid at room temperature. Consuming them may decrease blood cholesterol but appears to have no effect on high-density lipoprotein (HDL or "good" cholesterol). Sources include:

• nuts, including pecans, Brazil nuts, almonds, peanuts, cashews, and pistachios
• avocados, olives, other fatty vegetables
• canola, olive, and peanut oils

Polyunsaturated Fats: These fats are usually liquid at room temperature and may lower blood cholesterol if included as part of a low-fat diet. They have also, however, been associated with lowering levels of beneficial HDL cholesterol. Sources include:

• nuts including chestnuts, soy nuts, and walnuts
• pumpkin, sesame, and sunflower seeds
• safflower, sunflower, corn, soybean, sesame, and cottonseed oils

Cholesterol: Dietary cholesterol comes only from animal sources and will elevate blood cholesterol. American Heart Association guidelines recommend less than 300 milligrams of cholesterol a day.

You can do a lot to lower cholesterol levels through diet and regular exercise. Medication may be necessary if these lifestyle measures don't achieve the desired results.