Cholesterol
Cholesterol is a waxy substance present in all human beings. Cholesterol is vital for survival. It helps in repairing cell membranes, manufacturing Vitamin D and sex hormones like testosterone and estrogen and helps cell connections in the brain important for learning and memory. However it can also contribute to coronary artery disease leading to a heart attack.
How is cholesterol related to heart disease?
Cholesterol is carried in the bloodstream by special proteins known as lipoproteins. These lipoproteins are of the following types:
High Density Lipoprotein (HDL – good cholesterol) – This transports cholesterol away from arteries and heart muscles and is protective.
Low Density Lipoprotein (LDL – bad cholesterol) – This enters the arterial wall and heart muscles and deposits cholesterol in the arteries, contributing to heart disease.
Very Low Density Lipoprotein (VLDL) – This is like LDL cholesterol because it also penetrates the arterial wall.
Symptoms of high cholesterol level
There may be no warning signs of a high cholesterol level. When symptoms finally occur, they usually take the form of chest pain, heart attack or stroke. The high cholesterol levels not only affect arteries but also the heart muscles and increase the risk of heart failure.
High cholesterol and stroke
Having an adequate level of good cholesterol (HDL) may be the most important lipid related factor for preventing a stroke caused by blockage of the arteries that carry blood to the brain. If cholesterol builds up in these arteries, it may lead to them becoming narrower and irregular preventing proper blood flow to the brain. This may lead on to a stroke and possible paralysis.
Cholesterol’s effect on the heart
As many as half of all heart attacks are probably due to unhealthy cholesterol. Unhealthy cholesterol, especially LDL, forms a substance called plaque, which builds up in the arterial walls and causes a hardening of the arteries. This process is called atherosclerosis.
In atherosclerosis, the arteries becomes narrow and as this process continues, blood flow slows down, preventing sufficient oxygen-rich blood from being delivered to the heart. This condition leads to angina (chest pain) and in severe cases, to heart attacks, in which some heart muscle may die. This process is accelerated and enhanced by other risk factors like high blood pressure, diabetes, smoking, obesity and a sedentary lifestyle.
Fats and oils
Fat is a chemical compound containing fatty acids to keep the body healthy, while oils are a liquid form of fats. The consumption of fat provides people with a sense of fullness because it is digested more slowly than proteins and carbohydrates. A diet high in certain types of fat can lead to a significant rise in the levels of low density lipoprotein cholesterol (bad cholesterol).
The various types of fat are:
– Saturated fats
– Unsaturated fats
Polyunsaturated fats
Mono-unsaturated fats
Saturated fats – This fatty acid is the biggest source of bad cholesterol and is a major factor in the development of heart disease and strokes. Butter, margarine, meat (especially beef, lamb, pork), high-fat dairy products, cheese, cream, regular ice cream, yogurt, sour cream are major sources of saturated fats.
Unsaturated fats are derived from plants, nut oils and include polyunsaturated fats and mono-unsaturated fats. They are considered the healthiest form of fat. It does not cause a rise in the levels of bad cholesterol.
Mono-unsaturated fats are liquid at room temperature but solidify when placed in the refrigerator. Olive oil in an example.
Polyunsaturated fats are in a liquid state when kept at room temperature and in the refrigerator. An example is safflower oil.
Benefits of unsaturated fats
Unsaturated fats can help to lower cholesterol and low density lipoprotein cholesterol (bad cholesterol) and prevent fatty deposition (plaques) in arteries. This reduces the risk of heart attack and stroke.
Mono-unsaturated fats help by causing a rise in high density lipoprotein cholesterol (good cholesterol). High density cholesterol carries cholesterol from the blood back to the liver and helps prevent excess cholesterol deposition in arteries.
A type of polyunsaturated fat known as Omega 3 decreases the risk of heart attack and stroke by reducing both the cholesterol level and bad cholesterol levels in blood.
Good sources of mono-unsaturated fats
– Avocado
– Canola Oil, Olive Oil
– Peanuts, Almonds, Cashews
– Peanut Butter
Good sources of polyunsaturated fats
– Corn
– Fish and seafood
– Nuts and seeds (sunflower seeds)
– Safflower
– Soybeans
– Oils derived from these products
Good sources of Omega 3 fats
– Seafood
– Tuna
– Salmon
– Sardines
– Flax seeds, flax seed oil
– Walnuts
– Canola oil and soybean (in small amounts)
Diagnosis of high cholesterol levels
To obtain a reliable cholesterol reading you need the following conditions:
– Avoid strenuous exercise for 24 hours before the test.
– Do not eat or drink anything but water for 8-10 hours beforehand.
– If the first test result is abnormal, a second test should be performed between six to eight weeks after the first test.
Recommendations (cholesterol guidelines)
More than half of the adult population has blood cholesterol levels higher than the desirable range. High cholesterol levels often begin in childhood. Some children may be at a higher risk due to a family history of high cholesterol.
In general your total cholesterol should be less than 200 mg% because that level carries the least risk of heart disease. When the level is more than 200 mg%, the risk for heart disease increases. You should know your levels of good cholesterol (high density lipoprotein, HDL) and bad cholesterol (low density lipoprotein, LDL). Talk to your health care provider about what your cholesterol levels mean.
To lower high cholesterol levels:
– Limit total fat intake to 25-35 % of total daily calories. Less than 7% of daily calories should be from saturated fat, not more than 10% should be from polyunsaturated fat and not more than 20% from mono-unsaturated fat.
– Eat less than 200mg of dietary cholesterol per day.
– Get more fibre in your diet.
– Lose weight (if obese).
– Increase physical activity.
In conclusion, it is important to realize that not all cholesterol is bad. Strict adherence to the good forms of cholesterol in your diet with a lifestyle modification may go a long way in reducing the risks associated with high cholesterol levels.