A heart-healthy lifestyle is recommended for all Americans, but what is involved is not as simple as avoiding fatty foods.
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If you persist in pouring grease from your frying pan down the sink, you’ll soon end up with serious plumbing problems. In somewhat similar fashion, if you put excess fat in your blood stream, you may end up with obstructions in your arteries.
For the prevention of heart disease, the American public has readily bought into the plumbing analogy, and, even though it’s an over-simplification, it has prompted many Americans to reduce their risk of heart disease.
High blood cholesterol is a major risk factor for atherosclerosis–the build-up of fat-laden plaques that clog arteries, limit the flow of blood and lead to clots that are directly responsible for heart attacks and strokes. Doctors know that plaques or fatty streaks usually start occurring as early as childhood or adolescence, and most doctors recommend cholesterol testing at least every five years after age 20. A heart-healthy lifestyle is recommended for all Americans, but what is involved is not as simple as avoiding fatty foods.
Cholesterol is a waxy, fat-like substance that’s a building block of hormones and an important component of cell membranes. About 80 percent of the cholesterol in the blood stream is produced in the liver, and when everything is working as it should, the liver regulates the level–producing more cholesterol when it’s needed and clearing away any excess that builds up.
Saturated fats taken in through diet can increase cholesterol by 15 to 25 percent. In addition, some individuals are born with defective receptors that fail to process LDL cholesterol properly and sensors that mistakenly send messages to the liver that more cholesterol is needed when it’s not.
The Good, the Bad and the Ratio
There are many types of cholesterol, but two are implicated in heart disease. LDL (“bad cholesterol”) is easily deposited on artery walls. HDL (“good cholesterol”) has an ability to absorb cholesterol crystals and return them to the liver, thereby preventing the plaque buildup that leads to atherosclerosis.
While a total cholesterol under 200 mg/dL is generally recommended, doctors now look more carefully at the complete profile. HDL should be at least 40 mg/dL. The recommended upper level of LDL varies from 130 to 160 depending on the patient’s other risks for heart disease. Heart attacks rarely if ever occur with LDL under 100. Perhaps even more important is the ratio of total cholesterol to HDL, which should be under 4.5.
Knowing your numbers helps, but about half of heart attacks happen to individuals who have presumably safe levels–under 200 mg/dL total cholesterol or LDL between 130 and 160 mg/dL.
Excess weight, lack of exercise and smoking all have a negative effect on the cholesterol profile. Weight loss, smoking cessation and physical activity conversely are the best ways of raising HDL.
Many Americans find extreme low-fat diets difficult to follow, and recent studies indicate that they are not the only effective approaches.
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As for LDL, a high-fat diet is often the culprit, and one well established method for improving cholesterol is through a diet that derives 25 to 30 percent of calories from fat. Some plans recommending severe limitations on fat (10 to 15 percent of calories) have been found successful in halting or even reversing the buildup of fatty plaque in arteries. Many Americans, however, find these extremely low-fat diets difficult to follow, and recent studies indicate that they are not the only effective approach.
When it comes to HDL and LDL, fats are not created equal. Saturated fats, found mainly in meat and animal products such as whole milk, eggs and cheese, contribute most to the increase in LDL cholesterol. Polyunsaturated fats such as those in vegetable oils are more desirable, lowering both LDL and HDL cholesterol. Many of these products unfortunately are partially hydrogenated to make them more solid and spreadable like butter. As a result, they contain trans fatty acids which tend to provide a double whammy to the blood vessels–raising LDL and lowering HDL.
When diet and exercise are unable to keep cholesterol under control, medications may be prescribed.
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Monounsaturated fats–found in tree nuts, peanuts, olive oil and avocados–are now known to be beneficial to both HDL and LDL. Even when following a 35 percent total fat diet, persons who replace saturated with monounsaturated fats tend to achieve higher HDL and lower LDL levels. Most individuals find this kind of diet far more palatable, and the cholesterol improvements are comparable to or better than what they could achieve with a moderately low-fat regimen.
Omega-3 fatty acids, found in flaxseed flour and in fatty fish such as salmon, are also beneficial to the cardiovascular system, decreasing LDL while increasing HDL. These foods also help relax blood vessels and prevent clotting.
Other foods that can lower LDL cholesterol include soluble fiber, such as that found in fruits, vegetables and oat cereals; soy protein and both green and black tea. Alcohol, when consumed in moderation tends to increase HDL. Red wine and purple grape juice also contain antioxidant substances that have a positive effect on blood cholesterol and the cardiovascular system.
For the past decade or so, cholesterol-lowering margarines such as Benecol and Take Control have been available at the supermarket. These products contain plant stanols which block the absorption of cholesterol into the blood stream.
In randomized, controlled studies, subjects taking stanol margarine for a year lowered their total cholesterol by about 10 percent and their LDL by 14 percent. The margarine must be used regularly–about 1.6 grams or a tablespoon and a half a day.
But while diet and exercise should always be the first line of attack, they are not always adequate to keep cholesterol within safe limits. In such cases, cholesterol-lowering medications are recommended.
The most effective and the most frequently prescribed are statins which inhibit an enzyme the liver needs to manufacture cholesterol. Studies have demonstrated that statins lower LDL levels by 33 to 55 percent and reduce cardiovascular risk both in healthy persons and those with pre-existing heart disease. Statins have a good record for safety, but in rare instances can cause severe side effects such as liver damage and myopathy, a flu-like syndrome that can lead to muscle breakdown and kidney failure. They are also costly and should be reserved for persons who are unable to improve their cholesterol profiles through lifestyle measures.
For increasing HDL, other cholesterol-lowering medications may be even more effective. These include bile acid sequestrants such as cholestyramine (Questran) and colestipol (Colestid); fibric acid drugs such as gemfibrozil (Lopid), fenofibrate (Tricor) and clofibrate (Atromid) and Niacin, a B vitamin. These are often prescribed along with statins.
Medications can be very effective not only in improving a person’s cholesterol profile but also in reducing other heart disease risks. Whether you’re taking medication or not, however, it’s important to make a lifetime habit of getting regular exercise and following a balanced heart-healthy diet.
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