What is cholesterol and where does it come from
Cholesterol is a chemical that is required by the body to produce cell membranes and hormones such as estrogen and testosterone. The liver actually manufactures about 80% of the cholesterol in the body, while the rest comes from the food we eat.
Consequences of high cholesterol
Normally, cholesterol is transported in the blood attached to chemicals called lipoproteins. These contain varying amounts of protein in relation to the amount of cholesterol they carry. When the amount of cholesterol they carry is much higher than the protein, they are referred to as low-density lipoproteins (LDL). These are considered the ‘bad’ cholesterol in view of the high amount of cholesterol they carry.
When this type of cholesterol becomes excessive in the blood, it can accumulate and form deposits called plaques inside the walls of the arteries, causing them to narrow and preventing the free-flow of blood, leading to atherosclerosis. This decrease in the flow of blood raises the risk of heart disease, and rupture of the plaque may lead to a stroke or heart attack.
The second type of lipoprotein is the high-density lipoprotein (HDL), which contains a higher level of protein than cholesterol. This is considered the ‘good’ cholesterol on account of its low cholesterol level relative to protein. When the ratio of the HDL to LDL in the body is high, it potentially confers some protection against stroke and heart disease.
The third variety of lipoproteins, called the very low-density lipoproteins contain even lower amounts of protein than the low-density lipoproteins, so they may cause more plaque deposits than the LDL.
Foods to avoid
Fortunately, many of the foods we eat don’t significantly increase the level of cholesterol in the blood. However, foods high in saturated fats do cause this increase because they impact on the way the liver metabolizes cholesterol. Therefore, people who have been diagnosed with high levels of cholesterol in their blood and those with a family history should avoid foods that contain saturated fats.
Common foods that contain saturated fats and are high in cholesterol include animal products containing trans fats like margarine, butter, suet, lard, and spreads made from animal fats.
Another class of foods that contain saturated fats in dairy products. These include cheese, milk, yogurt, cream, and cheese. Products like sausages and meat pies that are made from processed meat, considered as fatty meat, are also high in saturated fats and should be avoided. Other foods containing saturated fats include coconut oil, palm oil, offal, and shellfish such as prawns.
Some foods contain low saturated fat but are high in cholesterol. For example, an egg is low in saturated fat, but the egg yolk is high in cholesterol. For many people, egg consumption has a small effect on their blood cholesterol, but those with a high level of cholesterol and those with a family history need to cut down on their consumption. Some processed foods such as biscuits and cakes which contain artificial trans-fats should also be avoided.
Which foods are safe to eat?
High-fiber foods such as wholemeal bread, bran, and wholegrain cereals can help lower cholesterol. Foods containing unsaturated fats can also help in reducing cholesterol levels in the blood. These include oily fish such as salmon and mackerel, vegetable oils such as sunflower, olive, and walnut oils. Foods that come from plants will not raise cholesterol, so grains, vegetables, lentils, beans, peas, and nuts are safe to eat. Grilling, steaming, and boiling will help to reduce the total amount of fat in your diet, so these processes should be preferred to frying and roasting.
Persons diagnosed by the doctor as having high cholesterol are usually placed on cholesterol-lowering medications such as statins. They will also be advised to get more active and make necessary adjustments to their diet. It is important that such persons get checked regularly by their doctor to reduce the risk of stroke and heart disease.