The four dietary fats are cholesterol and three forms of fatty acids-saturated,Ê monounsaturated,Ê andÊ polyunsaturated. Cholesterol and saturated fat have been found to contribute to the formation of plaque on the lining of arteries, the condition called arteriosclerosis, which was discussed above. Cholesterol is not a necessary nutrient because the liver is able to synthesize it, and high cholesterol levels in the bloodstream indicate an increased risk of heart disease. Cholesterol in the diet comes only from animal sources such as egg yolks, meat, milk, and butter.
Saturated fats, such as lard, animal fat, and coconut oil, tend to be denser and are solid at room temperature, whereas unsaturated fats are liquid. Saturated fats tend to raise the level of blood cholesterol because they are a precursor to the body's synthesis of cholesterol. Unfortunately, manufacturers of many baked goods like crackers, cookies, and muffins use highly saturated palm oil and coconut oil because they are less expensive ingredients.
Fat from plant sources is usually a mixture of the three types of fatty acids, with one type predominating. Polyunsaturated fats may help remove some of the cholesterol from the body, allowing it to be excreted in the feces. Monounsaturated fats seem to be neutral regarding the amount of cholesterol in the bloodstream, although some experts think this form of fat may decrease arteriosclerosis.
Researchers have found a strong link between a high-cholesterol, high-fat diet and heart disease and cancer. To improve your diet, reduce all fats, replacing some of the saturated fats with polyunsaturated fats. Studies have even indicated a link between cancer and a diet high in polyunsaturated fats.
This dietary change may not seem too important to you now. It is hoped that you are not overweight and that you are 40 or 50 years away from worrying about a heart attack. With a poor diet, however, you may involuntarily cut that time in half. People do have heart attacks in their thirties and forties, not necessarily as a result of a poor diet, but it can certainly be a contributing factor.
If you have a family history of heart disease, it is a good idea to go to a medical clinic for a blood test to measure your serum cholesterol. This measurement can be a good predictor of your risk of future heart disease. See Preventive Medicine for more information on lowering your risk of heart problems.