What is Cholesterol

Cholesterol is an oily, fatty substance made by the liver and also found in some foods.  Cholesterol comes from food sources such as meat, dairy products, and eggs.  Vegetables do not contain cholesterol.   The body uses cholesterol for a variety of things.  It uses it to produce certain hormones, like testosterone.  It uses it to cover nerves, insulating them to improve the efficiency of nerve transmissions.  It also uses cholesterol in the creation of cell tissues and membranes.  Your body needs cholesterol to function, but too much cholesterol can have harmful effects on your health. 

Since cholesterol cannot dissolve in the blood on its own, it is transported by various proteins.  These are normally what medical providers measure in your blood to check cholesterol levels.  LDL-cholesterol is low density lipoprotein cholesterol.  It is the major source of cholesterol in the bloodstream.  If it collects along the walls of blood vessels, it can cause a variety of health problems, including heart disease.  The vessels can become clogged, limiting blood flow to vital organs, such as the heart (causing a “heart attack”) or the brain (causing a “stroke”).  Your medical provider may refer to this as “bad cholesterol.”  HDL-cholesterol is high density lipoprotein cholesterol.  Researchers believe that this protein transports cholesterol back to the liver, possibly out of the collections along artery walls, and later out of the body.  High levels of this type of cholesterol seem to improve health outcomes.  For this reason, medical providers may refer to this as “good cholesterol.”

So how can someone lower their bad cholesterol and increase their good cholesterol?  Things that have been shown to lower bad cholesterol include limiting fatty foods in the diet that are high in cholesterol (fatty meats, cheeses, saturated fats, butter), and focusing more on fruits, vegetables, and whole grains.  Fibre is also found in plant foods, and a high fibre diet helps lower bad cholesterol in some people.  If you are overweight, losing weight may lower your bad cholesterol.  Regular exercise is one of the main ways to increase good cholesterol in most people.  Smoking lowers good cholesterol, so if you are a smoker, stopping smoking should improve the good cholesterol level and reduce your risk of heart disease and stroke.  There are also medications that can lower bad cholesterol and raise good cholesterol.  Discuss these with your healthcare provider, as they are not recommended for everyone.  

The issue of fat in food can be somewhat complicated.  Some fats seem to raise blood cholesterol levels, while others may lower them.  When reading food labels, look out for saturated fats and trans fats.  They are found more often in meats, some vegetable oils like coconut oil, and in prepackaged foods like baked goods or fast food. These seem to raise the bad cholesterol in the blood.  Polyunsaturated fats and monounsaturated fats may lower bad cholesterol in moderation, and they are more often found in fish and vegetable oils.

If you have additional questions after reading this series of articles, please consult your healthcare provider.

	Cholesterol levels