Cholesterol is a type of lipid (fat) produced by your liver and present in the food you eat. To be healthy, you need cholesterol because it performs several functions that are essential to the proper functioning of your body.
Nearly 90% of your body’s cholesterol is devoted to the membranes of your cells
It acts as a component of certain sex hormones (testosterone) or adrenal hormones (cortisone)
It steers the development of certain fetal cells
It promotes the formation of synapses in your brain
It is an ingredient in your bile, a liquid that allows lipids to be mixed with water to digest dietary fats
It is a vitamin D precursor
Cholesterol is transported in the blood by proteins called “lipoproteins” and includes LDL (Low Density Lipoprotein) and HDL (High Density Lipoprotein). “Total cholesterol” includes HDL and LDL cholesterol, referred to as good cholesterol and bas cholesterol respectively.
HDL lipoproteins collect cholesterol that has been deposited in the arteries, thus transporting cholesterol from the arteries to the liver where it is eliminated. HDL cholesterol removes poor-quality lipid deposits from the arteries. 20-30% of blood cholesterol is associated with HDL.
LDL lipoproteins, which are harmful to the body, deposit cholesterol on the walls of arteries, forming atherosclerotic plaques. This cholesterol tends to settle in the arteries and clog them. Between 60% and 80% of cholesterol in the blood is associated with LDL.
Triglycerides are also lipids, just like cholesterol, which are composed of glycerol and fatty acid molecules and stored in the fatty tissues of your body. These lipids are made in the small intestine, from fats brought in through food and during the metabolism of fast sugars by the liver. They are normally present in the body and are an important source of energy for your body.
High levels of triglycerides in the blood are a risk marker for cardiovascular disease.
Using a simple blood test, the lipid profile assesses the lipid content of your blood to determine your risk of developing cardiovascular disease. Normal rates are as follows:
LDL cholesterol (< 3.5 mmol/L)
HDL cholesterol (> 1.0 mmol/L for men, > 1.3 mmol/L for women)
Total cholesterol: (< 5.0 mmol/L)
Triglycerides (< 1.7 mmol/L)
Non-fasting lipid profile
In 2015, Biron’s medical laboratories innovated by offering non-fasting lab tests. Today, the Canadian Cardiovascular Society recognizes the relevance of this practice and encourages lipid measurements without fasting. In addition, the apolipoprotein B (Apo B) test is now included in all our lipid tests, adding value for the interpretation of results.
Hypercholesterolemia: Causes, Symptoms and Risks
Causes and Symptoms
Characterized by excess cholesterol, hypercholesterolemia has no symptoms, in the vast majority of cases, and does not exhibit clinical signs that can predict the serious complications it may cause, such as a stroke or heart attack.
The causes of hypercholesterolemia are congenital or acquired and are determined by many factors:
Age (cholesterol levels increase with age)
Gender (men have higher cholesterol levels)
Hereditary (family history of hypercholesterolemia)
It is characterized by a mutation in the gene coding the LDL cholesterol receptor on cells. If the receptor is absent, LDL cholesterol remains in the blood and accumulates (“bad” cholesterol deposits in the arteries). This type of hypercholesterolemia can occur as early as childhood.
Some conditions may lead to increased cholesterol in the blood, such as hypothyroidism, diabetes or kidney failure.
Environment, Age and Lifestyle
Everyone’s lifestyle plays an important role in rising cholesterol levels. A diet rich in fat and sugars, as well as minimal physical activity, results in excess weight and an increase in LDL cholesterol. Men over the age of 45 and menopausal women over the age of 55 have a higher risk of hypercholesterolemia.
According to Health Canada, more than 40% of Canadians between the ages of 20 and 79 have a total cholesterol that is harmful to their health. Increased health risks from high cholesterol may include:
The accumulation of plaque (a mixture of fat, calcium and cholesterol) and the blockage of blood vessels
Increased risk of heart attack or stroke because blood circulation is partially blocked
Poor circulation of blood in the blood vessels blocked by plaque or blood clots (thickening of the blood)
Screening and Prevention
High cholesterol screening is recommended for men over 40 and women over 50 or menopausal. It is also recommended for individuals with risk factors, including:
History of smoking
Excess abdominal fat
Family history of early heart attack or stroke
Physical signs of high cholesterol (such as fat deposits under the skin)
Evidence of vascular disease or coronary artery disease, with or without symptoms (aneurysms, kidney disease, peripheral artery disease)
Various public health agencies have issued dietary recommendations for the prevention and treatment of hypercholesterolemia (e.g., the American Heart Association, the working group on hypercholesterolemia and other dyslipidemias, the author of the Canadian guidelines). Here are some of the highlights:
Reduce your consumption of total fat to a maximum of 35% of total daily calories
Read labels on foods and avoid foods made with trans, hydrogenated or partially hydrogenated fats (fries, chips, donuts, crackers, hard margarines and bakery products)
Increase your consumption of foods that contain unsaturated fats (canola or olive oil, avocado, salmon and trout, unsalted nuts and seeds)
Make sure you consume enough soluble fibre, 10 to 25 g per day (wholegrain breads and cereals, oats, oat bran, psyllium, beans, peas, lentils, eggplant)
Include soy protein in your diet. Try to consume at least 20 grams per day (soy beverage, tofu and tempeh).
Eat a handful (1/4 cup) of unsalted nuts and seeds at least five times per week.
Choose foods that contain vegetable sterols such as whole grains, nuts, vegetables and fruits.
Manage your weight by losing any excess weight, especially around your waist (helps increase your HDL cholesterol and reduce your LDL cholesterol).
Be physically active. Exercising regularly improves HDL cholesterol. Any additional activity is beneficial.
Stop smoking. Studies show that avoiding tobacco can increase HDL cholesterol.