We know fat in the diet has been linked to an increased risk of heart disease, some cancers, and other chronic dis eases. Too much dietary fat can also contribute to obesity, a risk factor in itself for a slew of health problems, including coronary heart disease and certain cancers. To understand why too much fat in the diet is dangerous to good health, let’s look at what excessive amounts of fat can do in the hu man body.
A high-fat diet featuring foods from animal sources may result in an overconsumption of a particular kind of fat called saturated fat. Too much saturated fat can cause blood cholesterol levels to rise, increasing the risk of coronary heart disease. (Blood, or serum, cholesterol refers to the cholesterol in your bloodstream.) Foods high in saturated fatty acids include many types of meat, whole milk, lard, and butter, and a few plant foods such as coconut, palm, and palm kernel oil. Saturated fatty acids may soften at room temperature but still remain relatively firm instead of turn ing to liquid (like a stick of butter left on the counter—more spreadable but still a solid, not a liquid).
Polyunsaturated fatty acids include vegetable oils like corn oil, soybean oil, sunflower oil, and safflower oil, and the fat in most seafood. Polyunsaturated fatty acids are liq uid or very soft at room temperature. Some research suggests that excessive amounts of polyunsaturated fatty acids from these vegetable oils are linked to increased risk of can cer, but more research is required to confirm this. In the meantime, polyunsaturated fatty acids in moderate amounts may help to keep blood cholesterol levels low because they lower LDL, or “bad,” cholesterol levels. They also lower HDL, or “good,” cholesterol levels, however, making mono unsaturated fatty acids an even better choice.
Monounsaturated fat is the fat type that dominates the traditional Mediterranean diet. Foods rich in monounsaturated fatty acids include olive oil, canola oil, and most nuts and seeds. Liquid at room temperature, monounsaturated fatty acids in the diet have also been shown to lower LDL (“bad”) cholesterol levels, but not HDL (“good”) cholesterol levels in the blood, making it the fat of choice for a heart-healthy diet.
In other words, what you eat affects the amount of cholesterol in your blood. How much is too much? A serum cholesterol level above 240 mg/dl is considered high, and is associated with an increased risk of coronary heart disease. Between 200 and 239 mg/dl is considered borderline high, and below 200 mg/dl is considered desirable.
Cholesterol levels in the Mediterranean region during the 1960s were generally below 200 mg/dl. Although some of the diets in the traditional Mediterranean region were con sidered high in fat (especially on the isle of Crete), the saturated fat component was low. Because olive oil was the primary source of fat and the use of animal foods was not high, saturated fat intakes were kept in check. Furthermore, with saturated fats low, the heart-healthy monounsaturated fats take center stage.
EmoticonEmoticon