Blood Cholesterol - Keeping it Normal

Spring 2007 CSANews Issue 62  |  Posted date : Jun 06, 2007.Back to list

Many decades of research have proved that a high level of cholesterol in the blood exposes one to a much higher risk of cardiovascular disease, especially heart attack and stroke. Furthermore, successful early detection of high levels, and the necessary lifestyle modifications and drugs can lower cholesterol and reduce those risks.

Elevated cholesterol levels occur in almost 45 per cent of men and women. Men generally develop the problem earlier than women, but women have a higher prevalence after the age of 55.

Where does cholesterol come from?
About 80 per cent of the body's cholesterol is produced by your liver, with the remaining 20 per cent coming from your diet. It is needed for insulating nerves, building cells and producing hormones but if abnormal elevation occurs in your bloodstream, adverse effects can increase the risk of cardiovascular disease. Although there can be hereditary factors that cause raised cholesterol levels, our dietary intake and certain lifestyle choices are also responsible. Foods that contain saturated fat and trans fat (including snack pastries, dairy products, eggs, fatty meats, shrimp and organ meats) are particularly high in dietary cholesterol. Aggravating lifestyle factors include physical inactivity, smoking, excess alcohol consumption and obesity.

Monitoring your cholesterol levels
During an annual health examination, your physician will order an analysis of your blood cholesterol. Cholesterol is carried throughout the body by cholesterol-protein packets called lipoproteins. The two main lipoproteins are low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL is the "bad" cholesterol and when found to be elevated, requires attention. HDL is referred to as the "good cholesterol" because it carries the bad cholesterol from the cells back to the liver for excretion. The measured levels of these two are important, as well as the total cholesterol level and the ratio of the two. Measurement of another fat, triglyceride, is also done. Elevated levels of this fat can also be treated to reduce the risk of cardiovascular complications and occurs most often with obesity and diabetes.

Measurement of LDL cholesterol, HDL cholesterol and triglycerides allow for the calculation of both total cholesterol and the ratio of HDL to the total cholesterol. Depending on your individual results as well as any contributing cardiovascular risk factors, your doctor will advise regarding any required treatment of abnormal results. In Canada, measurements are made in mmol/L (millimoles per litre), whereas in the U.S. results are reported in mg/dL (milligrams per deci-litre). This can be confusing for snowbirds. If you have measurements done while wintering in the U.S., you can convert those cholesterol readings by dividing the U.S. numbers by 40, and the triglyceride reading by dividing the U.S. number by 90 to get the approximate Canadian readings.

Target Readings
The target cholesterol readings appear in this table.
Total cholesterol    Less than 5.2 mmol/L
LDL cholesterol    Less than 3.5 mmol/L
HDL cholesterol    For men: Higher than 1 mmol/L
    For women: Higher than 1.3 mmol/L
Total cholesterol/HDL cholesterol ratio    Less than 5 mmol/L
Triglycerides    Less than 1.7 mmol/L

Although these levels are target ranges for the general population, physicians may be more aggressive in managing cholesterol levels in patients with diabetes and proven arteriosclerosis, such as patients who have had a heart attack.

The buildup of high LDL cholesterol level in your blood hastens the development of "plaque" in arteries. This sticky substance, comprised mainly of cholesterol, has the effect of narrowing arteries throughout the body (arteriosclerosis), particularly the small coronary arteries supplying blood to heart muscle. As the artery narrows and the arterial lining is damaged, angina and/or a heart attack may occur due to the restriction of blood supply. If this occurs in the brain, a transient ischemic attack (TIA) or a full stroke may result. If in the legs, narrowed arteries can lead to poor circulation (peripheral artery disease) resulting in leg pain on exertion and gangrene in severe cases.

Accordingly, it is imperative that we keep our levels within a normal range. Stricter control will be required in persons who have documented evidence of arteriosclerosis, such as angina, TIA, heart attack, stroke or aneurysm, or persons who have a strong family history of cardiovascular disease. Those who have diabetes, smokers and obese persons also require special attention when managing cholesterol levels.

Lowering cholesterol by changing your lifestyle
Non-smoking, healthy eating and exercise
The first line of approach in dealing with slightly abnormal cholesterol levels is to make changes in one's lifestyle. Smoking is very damaging to other organs besides blood vessels and fortunately, has a low incidence in the Canadian senior population. Obesity is another factor to consider and if this is the case, serious weight reduction will have a positive effect on abnormal levels. In addition to caloric reduction, dietary intake of foods known to be high in saturated fats, trans fat and cholesterol should be reduced. Sedentary individuals should begin a dedicated exercise routine. For seniors, especially snowbirds, 30 minutes of brisk but comfortable walking most days of the week throughout the year is the most practical.

Medication
If these measures don't significantly reduce the levels to the normal range within six months, medication is indicated in addition to these objectives. By far the most effective drugs prescribed for cholesterol are from the "statin" family of drugs. They work by interfering with the liver's cholesterol-producing mechanism and its capacity to remove cholesterol from the blood stream. In Canada, these include Lipitor (atorvastatin), Mevacor (lovastatin), Crestor (rosuvastatin), Zocor (simvastatin), Lescol (fluvastatin) and Pravacol (pravastatin). Although side-effects are rare with these medications, a rare but serious muscle-damaging condition has been associated with their use. Accordingly, Health Canada requires manufacturers to include side-effect warnings with the safety information sheet provided by your pharmacist. Be sure to read it. These drugs, when prescribed in appropriate doses, reduce elevated cholesterol levels to normal and have a profound effect in reducing cardiovascular conditions.

Other drugs are occasionally used including nicotinic acid (niacin), resins (Questran) and fibric acid derivatives (fenofibrate). Although less costly, these drugs are less likely to achieve normal cholesterol levels.

Whatever drug is used, be certain to continue the other measures to maintain normal levels, especially your dietary restrictions, weight control and exercise.

Eating in
Making dietary choices is easier when eating at home. Those same choices are more difficult when eating out. The following general dietary choices are recommended for individuals with a cholesterol condition, whether or not medication has been prescribed.

Exercise, maintaining a healthy weight, avoiding smoking and restriction of dietary saturated and trans fats are the most important individual actions that will lower your cholesterol. Even if medication is still required, the dose of the prescribed drug and the risk of adverse reactions will be lower.

What to buy
When shopping, be sure that your cart has plenty of vegetables and fruit. Whole-grain cereals and breads are important as well, but try and search for actual whole grain, because many of the "brown" breads do not contain all parts of the grain. Buy skim or low-fat milk and non-hydrogenated margarine, but certainly avoid whole milk, cream, butter and ice cream. Meats should be lean, such as poultry, and fish (with its healthy Omega 3 fatty acids) is beneficial to your heart health. Beans and other vegetables can replace some of your meat meals.

Not all fats are unhealthy. For instance, while coconut and palm oils contain saturated fats and should be avoided, olive, canola, peanut, corn and sunflower oils along with walnuts and pecans are considered healthy fats. Just watch the calories! Cookies, pastries, chips, donuts and fries all contain saturated or trans fats and should be eliminated from your shopping list. Learn to read and interpret the nutrition labels before making choices.

Eating out
Eating out is more of a challenge. In many malls and restaurants, it is often difficult to find wholesome food. Many fast foods are rich in saturated and trans fats, although many restaurants have begun to eliminate at least the harmful trans fat from their products. If attending functions at which choice might be limited, remember to pack your own healthy meal, if possible. When snacking, pack fruits, raw vegetables or low-fat cheese and whole-grain crackers.

All-around healthy?
Remember that high blood cholesterol is only one of the risk factors for heart attack and stroke. In addition to maintaining a healthy range of your cholesterol levels, be sure to keep exercising, maintain a normal weight, avoid cigarette smoke and be sure that most of your blood pressure readings are below 140/90. If you have diabetes, you must be even more diligent in achieving normal cholesterol and weight levels as well as keeping your blood pressure below 130/80.

Remember the old adage, "an ounce of prevention is worth a pound of cure!" Keeping your cholesterol at a normal level is a proven way to maintain better health.

Fast Facts about cholesterol
  • High cholesterol typically has no symptoms; it's usually found by routine blood tests.
  • Blood cholesterol levels in both men and women begin to elevate at around age 20.
  • Women before menopause have levels that are lower than men of the same age. After menopause, a woman's LDL cholesterol level goes up –so her risk for heart disease increases.
  • Abnormally low cholesterol is called hypocholesterolemia and, while not much is known about its long-term effects, scientists theorize that it can cause depression, cancer, hemorrhagic stroke and respiratory diseases.




Related links
Canadian Heart and Stroke Foundation
Making the Connection – Pfizer Canada’s website about cholesterol