Cholesterol is a type of fat (lipid), found both in the body and in certain foods. It has spent its fair share of time in the news because of its association with heart disease and stroke, but in fact, cholesterol is a vital substance, found in the blood and in every cell of the body. It is one of the building blocks of cell membranes, and the body uses it to make vitamin D and hormones.
However, too much cholesterol in the blood can increase your risk of heart disease and stroke by leading to a buildup of plaque on artery walls. Eventually, the plaque can narrow the arteries (atherosclerosis), reducing blood flow. If a blood clot forms and blocks an artery to the heart artery, a heart attack can occur. If a blood clot blocks an artery to or in the brain, a stroke results.
The trick is to ensure that you have the right balance of cholesterol in the blood. If your cholesterol level is too high, making simple dietary and lifestyle changes – such as eating less fat and increasing physical activity – can lower your cholesterol, and therefore your risk of heart disease and stroke.
Why is it so important to watch your cholesterol? In Canada, 45% of men and 43% of women have unhealthy cholesterol levels. Most heart and blood vessel disease is caused by a buildup of cholesterol, plaque and other fatty deposits on artery walls. Cardiovascular disease accounts for the death of more Canadians than any other disease; and stroke is the fourth leading cause of death in Canada.
There is only one way to find out if your cholesterol is too high, and that is to be tested. Talk to your doctor about testing your cholesterol if you have any of these risk factors:
Finding out if you are at risk for heart disease and stroke will give you the opportunity to make important diet and lifestyle changes – changes that can significantly reduce your risks. And the sooner you find out, and begin making changes, the better. Your reward will not only include lower cholesterol, but better health, and increased energy, vitality and longevity.
Cholesterol is a soft waxy substance. The word “cholesterol” can refer to either blood cholesterol (cholesterol found in the body) or dietary cholesterol (cholesterol found in foods). Blood cholesterol, made by the liver, comprises about 80% of the cholesterol in the body. The remaining 20% comes from the foods we eat.
Cholesterol is transported in the blood by lipoproteins. There are two main types of cholesterol:
Recent research has also found that HDL may do other things as well, such as prevent the ruptures that cause blood clots and block blood flow. However, scientists have recently discovered that HDL can be different in people who have heart disease and those who do not. This may mean that that some of the supposedly “good” HDL is really “bad.” So, measuring blood levels of LDL and HDL cholesterol may not be as accurate about predicting heart attack risk as has been assumed. A better understanding of how HDL operates is needed, but in the meantime, doctors still recommend following a low-fat diet and a healthy lifestyle to reduce risk.
Cholesterol levels are closely linked to intake of dietary fat. The foods that raise your LDL blood cholesterol the most are saturated fat and trans fat. Saturated fats are found in foods such as fatty meats, shrimp, egg yolks, full-fat milk products, butter, lard, coconut, palm and palm kernel oil, fast foods, snack foods, many prepared foods and those made with hydrogenated vegetable oil.
Trans fats are found in foods made with shortening or partially hydrogenated vegetable oil, fast foods, snack foods and many prepared foods. Trans fats not only raise LDL cholesterol, they also lower HDL cholesterol.
On the plus side, there are a number of foods that lower LDL cholesterol, such as soluble fibre (found in foods such as oatmeal, kidney beans, brussels sprouts, apples, pears, psyllium, barley and prunes); polyunsaturated fatty acids (found in foods such as walnuts and almonds); omega-3 fatty acids (found in fish – especially mackerel, lake trout, herring, sardines, albacore tuna and salmon – flaxseed, canola and soybean oil); and plant sterols.
The good news about cholesterol is that it can usually be lowered by eating less LDL cholesterol-increasing foods and more LDL cholesterol-lowering foods, and by adopting a healthy lifestyle.
The most important steps to following a healthy lifestyle are:
All of these factors, taken together, can dramatically decrease your risk of heart disease and stroke by lowering your LDL cholesterol level and your blood pressure, and raising your HDL cholesterol.
Lowering your LDL cholesterol (and your weight) by eating healthy foods low in fat is easy and simple, especially once you get in the habit. Begin by slowly replacing favourite high-fat foods with low-fat choices. Generally speaking, your diet should be comprised mainly of foods low in total carbohydrates, saturated and trans-fatty acids; and high in complex carbohydrates, protein, and mono- and polyunsaturated fat.
Follow these guidelines for heart-healthy eating:
There are certain risk factors for heart disease and stroke that you can’t control, such as your age, ethnicity and family medical history. But there are things you can control, such as your diet and lifestyle choices.
Following a healthy, low-fat diet almost always lowers cholesterol levels. So does not smoking (smoking increases LDL cholesterol); maintaining a healthy weight (being overweight lowers your HDL cholesterol and increases your risk of heart disease and stroke); and getting regular exercise (exercising regularly decreases cholesterol). Aim for about 30 to 60 minutes of moderate exercise each day. Regular physical activity can cut the risk of heart disease and stroke in half.
Finally, reducing your stress is also a key factor to maintaining a healthy lifestyle and lowering your risk of heart disease and stroke. Researchers believe there may be a link between stress and increased blood cholesterol and higher blood pressure. There are many things you can do to manage your stress, such as going out for a walk, doing some deep breathing exercises, talking to a friend, laughing at a funny book or movie and practicing time management.
If, after three to six months, following a healthy diet and lifestyle does not significantly decrease your cholesterol, you may need to talk to your doctor about medication. There are several types of drugs available to lower your cholesterol and your doctor will help you choose the best one for you – but keep in mind that these medications do not cure high cholesterol. And neither do they replace a healthy lifestyle.
Public Health Agency of Canada - The Healthy Heart Kit
Heart and Stroke Foundation of Canada
Health Canada - It's Your Health - Trans Fat
Active Living in Your Neighbourhood
How to Achieve Healthy Blood Cholesterol Levels
Canada has a new Food Guide