Fat, Cholesterol and Heart Disease
Heart disease is in the US, as in most westernized countries, the nation’s leading cause of death, killing one in every three Americans. Over seven million Americans suffer from angina pectoris and its severe, recurring pain caused by partial blockage of the coronary arteries. One in three men can expect to develop a cardiovascular disease before the age of 60.
Several different factors contribute to the risk of developing heart disease. High blood pressure, diabetes and high cholesterol levels in the blood all can play a role. Lifestyle factors such as smoking, obesity and physical inactivity can add to the danger. Indeed, the majority of heart attacks occur in people whose total blood cholesterol levels are between 180 and 240 and who have other risk factors, such as tobacco smoking, diabetes, a sedentary lifestyle or a family history of heart disease.
Nonetheless, none of these risk factors, or even a combination of them, is known to guarantee that you will develop a heart disease. For example, a majority of people with high cholesterol never die of heart disease. However, since the doctors have no way of predicting whether or not you will be among those lucky ones, the only wise course is to keep the odds in your favor. This means minimizing all the risk factors you can, and, when it comes to your diet, trying to reduce your cholesterol levels. As a rule of thumb, for every one percent decrease in cholesterol, your chance of having a heart attack declines by two percent. And for every ten percent decrease in cholesterol, your chance of developing heart disease declines by a remarkable thirty percent.
Facts About Cholesterol
Cholesterol is not fundamentally bad. In fact, this waxy, fat-like substance is a necessary part of our body chemistry. It is found in all animals and in all animal products (such as meats, milk, cheese and eggs). However, there is no cholesterol present in any plant product or the oils made from them.
There is no need for cholesterol in our diet since the human liver is able to produce all that we require. Excessive cholesterol, whether manufactured by the body or from the diet becomes a threat when it finds its way into the arteries, where it is deposited as a thick, fatty plaque. White blood cells attack the plaque, creating debris. In addition, the artery tries to heal itself by growing more cells in its walls. This build-up of plaque, debris and additional cells narrows and stiffens the artery, thus creating a condition called atherosclerosis. If the constriction occurs in an artery serving the brain, there is danger of the total blockage called a stroke. If this happens in a vessel supplying the heart muscle, it can slow down the flow of oxygen-rich blood required by the muscle and eventually lead to a heart attack. Often there are no symptoms of atherosclerosis until it is too late and after a stroke or heart attack has already occurred.
Special carriers, called lipoproteins, transport cholesterol through the bloodstream. Two of the most essential carriers are low-density lipoproteins (LDL) and high-density lipoproteins (HDL). The more abundant form of lipoprotein is LDL, commonly referred to as “bad cholesterol.” High levels of LDL are commonly associated with an increased risk of heart disease. High levels of HDL, the “good cholesterol”, are known to prevent the heart disease while low levels seem to encourage it. So the lower your LDL cholesterol levels and the higher your HDL level, the better off you are. If your LDL level is too high, chances are that your triglycerides (blood fat) will be high as well.
Most doctors recommend a total blood cholesterol level of less than 200 milligrams per deciliter of blood and an HDL level greater than 40 milligrams per deciliter. Depending on your individual risk factors for heart disease, an ideal level of LDL is 1) less than 100 milligrams per decilitre (so called optimal level) if you already have heart disease or have a condition, such as diabetes, that puts you at high risk of developing heart disease, 2) an LDL level less than 130 milligrams per decilitre (near optimal level) if you have two or more risk factors, including low HDL cholesterol and advancing age and 3) an LDL level less than 160 milligrams per decilitre (borderline high level) if you have no more than one risk factor.
All other factors being equal, a person with a total blood cholesterol level of 240 is twice as likely to have a heart attack as one with a level of 200. A level of 300 carries even five times the risk of a level of 200. Conversely, a 25% decline in total blood cholesterol levels can cut the heart attack risk in half.
However, total blood cholesterol tells only part of the story. In fact, the type of cholesterol makes a big difference. While LDL contributes to artery-blocking deposits of plaque, the HDL helps to remove excess cholesterol from the bloodstream. As it was mentioned earlier, a high level of LDL is not good, neither is a low level of HDL. Therefore, a good measure of heart disease risk is the ratio of total cholesterol to HDL. A ratio of 2.5 or lower is good whereas a ratio of 4 and above calls for further discussion with your doctor.
A low triglyceride (blood fat) level also happens to be a critical factor regarding the health of your heart as there is a direct link between high triglyceride levels and atherosclerosis. Excessive triglycerides typically accompany higher total cholesterol and LDL levels and lower HDL levels. Ideally, your triglyceride levels should be below 150 milligrams per deciliter. The same dietary and lifestyle changes that help to reduce total cholesterol and LDL levels are also known to have a positive impact on triglycerides.
It is also recommended that you have your blood cholesterol levels and triglycerides checked regularly, ideally beginning at age 20. Since lifestyle factors and heredity are critical variables, your doctor is in the best position to interpret the results and suggest an appropriate course of action. The most common therapy for high LDL cholesterol includes a low-fat diet, losing weight, regular exercise, giving up smoking and in some cases also medications.
Lowering Your Cholesterol Levels
When lowering your cholesterol, cutting it out of your diet is only part of the answer as saturated fat and trans fat can also raise blood cholesterol. Keeping saturated and trans fat under 10-15% of your total calories intake is a crucial first step. When it comes to dietary cholesterol, individual tolerance of cholesterol varies but the doctors recommend restricting its intake to no more than 300mg per day. As an example, a three-ounce serving of broiled liver contains 330mg of cholesterol whereas an equivalent portion of beef has only 75mg.
In most cases, relatively minor changes in the diet, such as eliminating butter, margarine, snacks, fast food, French fries, etc., can lower cholesterol by 10-15%. Keeping your consumption of meat to about six ounces per day can also work wonders as it cuts down your intake of both cholesterol and saturated fat. Regular exercise happens to be the only proven way of raising your “good” HDL levels and thus eliminating adverse effects of “bad” cholesterol. The results can be really rewarding. An 8-20% reduction in blood cholesterol levels typically translates into a 20-40% reduction in heart attacks.
If your cholesterol levels do not respond to diet and exercise, your doctor may need to prescribe a medication, most likely a statin. Statins attack cholesterol in two ways, vacuuming harmful LDL out of the blood and limiting the body’s ability to produce new LDL. These drugs include trade names such as Lescol, Lipitor, Livalo, Mevacor, Pravachol and Zocor. Statins have been shown to substantially reduce the risk of a heart attack in people with high cholesterol. Patients who cannot take statins may be prescribed a medication from the group of fibric acid derivatives or occasionally one of the bile acid sequestrants, which are typically used as an adjunct to the statins.
Fat, especially saturated fat and trans fat, is not only a high-calorie food that threatens our waistline, it is also a demonstrated risk factor for heart disease and diabetes. Remember that no more than 30% of our daily caloric intake should come from fat and possibly no more than 10-15% from saturated and trans fat.
Where to Find More Information: American Heart Association