High cholesterol levels can be caused by a number of factors. Top of the list would be a poor diet consisting of a high intake of carbohydrates, transfats and a lack of fiber.
A high level of fat and cholesterol in the diet is usually blamed for elevated blood cholesterol. While this may be true, the real villians are sugar and an excess intake of carbohydrates. We need carbohydrates but for most of us, our sedentary lives never allow us to burn them off. Excess carbohydrates is converted into glucose and later in to cholesterol and triglycerides which is a major risk factor for heart disease.
The vegetable oil that we use to cook is also a contributor. In the process of making these oil, some of these gets converted into transfats. Further if you cook at high temperatures e.g. deep frying you create more transfat. Transfats have an adverse effect on our blood fats because they can increase the level of LDL or 'bad cholesterol' and reduce the levels of HDL or 'good cholesterol'. Transfats can incorporate themselves into our cell membrane and when they do, they can interfere with the action of insulin promoting insulin resistance leading to diabetes.
One of the way our body gets rid of excess fiber is through bowel movement. The fiber in our diet absorbs cholesterol and prevents it from being reabsorbed back into the bloodstream. Hence a lack of fiber in out diet can increase cholesterol levels.
A high level of cholesterol can also be caused by genetic factors. Our genes affect how fast LDL cholesterol is made and removed from our blood. A genetic anomaly can produce severe elevation in total and LDL cholesterol. These defective genes can pass from parents to their offsprings.
Elevated cholesterol can be caused by a condition called hypothyroidism where the thyroid gland is under active. This slows the metabolism down and affects the ability to process cholesterol resulting in elevated cholesterol levels.
Then there is stress. When we are stressed we often adopt unhealthy habits such as overeating, taking sweets, smoking and drinking each of which can increase our cholesterol levels.
A sedentary lifestyle can lead to higher cholesterol levels. Regular exercise not only reduces total blood cholesterol, but it lowers the bad kind of cholesterol (LDL cholesterol) while raising the good kind of cholesterol (HDL cholesterol).
Finally there is smoking which can raise blood cholesterol levels as well as blood pressure levels. The nicotine in cigrettes stimulates the release of stress hormone adrenaline, which in turn stimulates the breakdown of fats and increases blood levels of free fatty acids. These then stimulates the liver to produce LDL cholesterol and triglycerides into the bloodstream. Smoking may also reduce the level of protective HDL cholesterol.
According to the World Health Organization, there is hope for smokers. Studies show that the risk of having a heart attack, stroke or peripheral arterial disease drops significantly after the first two years of quitting!