What is Cholesterol?
Cholesterol is a waxy, fat-like substance made in the liver and other cells and found in certain foods, such as food from animals, like dairy products, eggs, and meat. The body needs some cholesterol in order to function properly. Its cell walls, or membranes, need cholesterol in order to produce hormones, vitamin D, and the bile acids that help to digest fat. But the body needs only a limited amount of cholesterol to meet its needs. When too much is present health problems such as heart disease may develop.
Cholesterol and Heart Disease
When too much cholesterol is present, plaque (a thick, hard deposit) may form in the body’s arteries narrowing the space for blood to flow to the heart. Over time, this build up causes atherosclerosis (hardening of the arteries) which can lead to heart disease.
When not enough oxygen-carrying blood reaches the heart chest pain called angina can result. If the blood supply to a portion of the heart is completely cut off by total blockage of a coronary artery, the result is a heart attack. This is usually due to a sudden closure from a blood clot forming on top of a previous narrowing.
Types of Cholesterol
Cholesterol travels through the blood attached to a protein — this cholesterol-protein package is called a lipoprotein. Lipoproteins are classified as high density, low density, or very low density, depending on how much protein there is in relation to fat.
- Low density lipoproteins (LDL): LDL, also called “bad” cholesterol, can cause build-up of plaque on the walls of arteries. The more LDL there is in the blood, the greater the risk of heart disease.
- High density lipoproteins (HDL): HDL, also called “good” cholesterol, helps the body get rid of bad cholesterol in the blood. The higher the level of HDL cholesterol, the better. If levels of HDL are low, the risk of heart disease increases.
- Very low density lipoproteins (VLDL): VLDL is similar to LDL cholesterol in that it contains mostly fat and not much protein.
- Triglycerides: Triglycerides are another type of fat that is carried in the blood by very low density lipoproteins. Excess calories, alcohol, or sugar in the body are converted into triglycerides and stored in fat cells throughout the body.
What are normal cholesterol levels?
The amount of cholesterol in human blood can vary from 3.6 mmol/litre to 7.8 mmol/litre. The Government of Alberta in Canada says that any reading over 6 mmol/litre is high and will significantly raise the risk of arterial disease.
Below is a list of cholesterol levels and how most doctors would categorize them 5mmol/litre (millimoles/litre).
- Optimum level: less than 5mmol/litre.
- Mildly high cholesterol level: between 5 to 6.4mmol/litre.
- Moderately high cholesterol level: between 6.5 to 7.8mmol/litre.
- Very high cholesterol level: above 7.8mmol/litre.
What Factors Affect Cholesterol Levels?
A variety of factors can affect cholesterol levels. They include:
- Diet. Saturated fat and cholesterol in the food you eat increase cholesterol levels. Try to reduce the amount of saturated fat and cholesterol in your diet.
- Weight. In addition to being a risk factor for heart disease, being overweight can also increase cholesterol. Losing weight can help lower your LDL and total cholesterol levels, as well as increase HDL cholesterol.
- Exercise. Regular exercise can lower LDL cholesterol and raise HDL cholesterol. You should try to be physically active for at least 30 minutes on most days.
- Age and Gender. As we get older, cholesterol levels rise. Before menopause, women tend to have lower total cholesterol levels than men of the same age. After menopause, however, women’s LDL levels tend to rise.
- Diabetes. Poorly controlled diabetes increases cholesterol levels. With improvements in control, cholesterol levels can fall.
- Heredity. Your genes partly determine how much cholesterol the body makes. High blood cholesterol can run in families.
- Other causes. Certain medications and medical conditions can cause high cholesterol.
High cholesterol levels can cause:
- Atherosclerosis – narrowing of the arteries.
- Higher coronary heart disease risk – an abnormality of the arteries that supply blood and oxygen to the heart.
- Heart attack – occurs when the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in a coronary artery. This causes your heart muscle to die.
- Angina – chest pain or discomfort that occurs when your heart muscle does not get enough blood.
- Stroke and mini-stroke – occurs when a blood clot blocks an artery or vein, interrupting the flow to an area of the brain. Can also occur when a blood vessel breaks. Brain cells begin to die.
- If both blood cholesterol and triglyceride levels are high, the risk of developing coronary heart disease rises significantly.
What are the treatment options for high cholesterol?
If your cholesterol levels are still high after doing everything mentioned above, your doctor may prescribe a cholesterol-lowering drug. They may include the following:
- Statins (HMG-CoA reductase inhibitors) – these block an enzyme in your liver that produces cholesterol. The aim here is to reduce your cholesterol levels to under 4 mmol and under 2 mmol for your LDL. Statins are useful for the treatment and prevention of atherosclerosis. Atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin and simvastatin are examples of statins.
- Aspirin – Used as a blood thinner to prevent clots
- Niacin – this is a B vitamin that exists in various foods. You can only get very high doses with a doctor’s prescription. Niacin brings down both LDL and HDL levels
- Anti-hypertensive drugs – if you have high blood pressure your doctor may prescribe Angiotensin-converting enzyme (ACE) inhibitors, Angiotensin receptor blockers (ARBs), Diuretics, Beta-blockers, Calcium channel blockers.
Most people, especially those whose only risk factor has been diet and lifestyle, can generally get their cholesterol and triglyceride levels back to normal by:
- Doing plenty of exercise (check with your doctor).
- Getting plenty of sleep (8 hours each night).
- Bringing your bodyweight back to normal.
- Avoiding excessive alcohol intake (as alcohol increases triglycerides)
- Stopping smoking.
- Modifying your diet
Diet plays an important role in lowering your cholesterol. A few simple tweaks to your diet, along with exercise and other heart-healthy habits will help lower your cholesterol. Here are five ways that can lower your cholesterol and protect your heart.
- Oatmeal, oat bran and high-fibre foods. Oatmeal contains soluble fibre, which reduces your low-density lipoprotein (LDL), the “bad,” cholesterol. Soluble fibre is also found in such foods as kidney beans, apples, pears, barley, wholemeal bread, grains and prunes. Soluble fibre can reduce the absorption of cholesterol into your bloodstream. Five to 10 grams or more of soluble fibre a day decreases your total and LDL cholesterol. Eating 1 1/2 cups of cooked oatmeal provides 6 grams of fibre. If you add fruit, such as bananas, you’ll add about 4 more grams of fibre.
- Fish and omega-3 fatty acids. Eating fatty fish can be heart healthy because of its high levels of omega-3 fatty acids, which can reduce your blood pressure and risk of developing blood clots. In people who have already had heart attacks, fish oil or omega-3 fatty acids reduce the risk of sudden death. The American Heart Association recommends eating at least two servings of fish a week. The highest levels of omega-3 fatty acids are in:
- • Mackerel
- • Lake trout
- • Herring
- • Sardines
- • Albacore tuna
- • Salmon
- • Halibut
- You should bake or grill the fish to avoid adding unhealthy fats. If you don’t like fish, you can also get small amounts of omega-3 fatty acids from foods like ground flaxseed or canola oil. You can take an omega-3 or fish oil supplement to get some of the benefits, but you won’t get other nutrients in fish, such as selenium. If you decide to take a supplement, just remember to watch your diet and eat lean meat or vegetables in place of fish.
- Walnuts, almonds and other nuts. Walnuts, almonds and other nuts can reduce blood cholesterol. Rich in polyunsaturated fatty acids, walnuts also help keep blood vessels healthy. Eating about a handful (1.5 ounces, or 42.5 grams) a day of most nuts, such as almonds, hazelnuts, peanuts, pecans, some pine nuts, pistachio nuts and walnuts, may reduce your risk of heart disease. Just make sure the nuts you eat aren’t salted or coated with sugar. All nuts are high in calories, so a handful will do. To avoid eating too many nuts and gaining weight, replace foods high in saturated fat with nuts. For example, instead of a sugary snack or using cheese, meat or croutons in your food, add a handful of walnuts or almonds.
- Olive Oil. Olive oil contains a potent mix of antioxidants that can lower your “bad” (LDL) cholesterol but leave your “good” (HDL) cholesterol untouched. Try using about 2 tablespoons (23 grams) of olive oil a day in place of other fats in your diet to get its heart-healthy benefits. To add olive oil to your diet, you can sauté vegetables in it, add it to a marinade or mix it with vinegar as a salad dressing. You can also use olive oil as a substitute for butter when basting meat or as a dip for bread. Olive oil is high in calories, so don’t eat more than the recommended amount. The cholesterol-lowering effects of olive oil are even greater if you choose extra-virgin olive oil, meaning the oil is less processed and contains more heart-healthy antioxidants. But keep in mind that “light” olive oils are usually more processed than extra-virgin or virgin olive oils and are lighter in colour, not fat or calories.
- Foods with added plant sterols or stanols. Foods are now available that have been fortified with sterols or stanols substances found in plants that help block the absorption of cholesterol for example, Flora proactive products or Danone Danacol range. Margarines, orange juice and yogurt drinks with added plant sterols can help reduce LDL cholesterol by more than 10 percent. The amount of daily plant sterols needed for results is at least 2 grams — which equals about two 8-ounce (237-milliliter) servings of plant sterol-fortified orange juice a day. Plant sterols or stanols in fortified foods don’t appear to affect levels of triglycerides or of high-density lipoprotein (HDL), the “good” cholesterol.
Other changes to your Diet
Although these foods provide benefit to lowering your cholesterol, making other changes to your diet and lifestyle can also help. Cut back on the cholesterol and total fat, especially saturated and trans fats that you eat. Saturated fats, like those in meat, full-fat dairy products and some oils, raise your total cholesterol. Trans fats, which are sometimes found in margarines and store-bought cookies, crackers and cakes, are particularly bad for your cholesterol levels. Trans fats raise low-density lipoprotein (LDL), the “bad,” cholesterol, and lower high-density lipoprotein (HDL), the “good,” cholesterol.
In addition to changing your diet, keep in mind that making additional heart-healthy lifestyle changes are key to lowering your cholesterol. Talk to your doctor about exercising, quitting smoking and maintaining a healthy weight to help keep your cholesterol level low.