Statins are the most controversial drugs, and are readily prescribed to millions of people who have high cholesterol levels. This article will explore how statins work, the scientific evidence for their health benefits, and investigate the potential negative health effects they have.
Statins & The Cardiovascular System
Cholesterol is synthesized in the liver, and is transported in the blood by lipoproteins, the most abundant being HDL (high density lipoproteins) and LDL (low density lipoproteins). LDL carries cholesterol from the liver to various parts of the body where is used to repair or add rigidity to membranes, and HDL transport cholesterol from organs back to the liver. LDL is considered to be ‘bad’ cholesterol, as raised levels of it are strongly linked to an increased risk of developing cardiovascular disease.
Statins lower the circulating LDL levels by inhibiting the action of the enzyme in the liver which creates cholesterol (enzyme HMG-CoA reductase). This reduction in cholesterol production results in a reduction of circulating LDL. This mechanism is very simple, and evaluation by the Cochrane group has concluded that statins are an effective treatment for prevention of cardiovascular disease via this mechanism. The LDL lowering properties on patients can vary dramatically, from 10%-80%, and can reduce LDL too much, meaning that anyone taking statins requires regular blood tests to ensure LDL levels are healthy. Statins have also shown to posses antioxidant properties, which may offer additional protection to the cardiovascular system and the rest of the body.
Reasons for Concern
There is evidence that statins, or at least some types of statins may increase the risk of developing type 2 diabetes. This is of particular concern as the majority of patients who are prescribed statins are males over the age of 40, and this is the highest risk group for developing type 2 diabetes. The scientific evidence for this is inconsistent, with some studies having negative results and others showing positive, and there has been no mechanism identified for this action. However, the statin which has shown to be most effective at increasing the risk of type 2 diabetes is pravastatin, and so should be avoided.
There is growing concern over the effects of statins on the liver, as there is an increasing amount of evidence to show that statins increase liver enzymes, change the fatty acid composition of liver and can cause inflammation. All these effects indicate an increased amount of stress on the liver, and can lead to other diseases, and weaken the bodies ability to metabolize toxins. Although these ailments do not pose an immediate threat to patients, if these symptoms persist (as they could with regular statin consumption) they could result in liver damage, especially if the patient is a regular consumer of alcohol. There have in fact been a small number of patients which have had sever liver damage as a result of statins. The extent and severity of these symptoms are unclear though, and it is also possible that different types of statins affect the liver in different ways. There is still much research needed in this area to investigate the full extent of statins on the liver.
The development of cancer from the consumption of statins is also a major concern. This is extremely difficult to measure and conduct conclusive research on, but may studies have investigated it. A meta-analysis of these studies has shown that there is no short term risk of cancer development, but the long term risk is inconclusive. To make the subject even more complicated, there is also evidence that statins can help to prevent certain types of cancer, but again, this is inconclusive.
Many vitamins (such as vitamin A, D, and E) and co-factors (such as co-enzyme Q10) are fat soluble, and so need to be transported in fat in the blood to reach all body. People who are taking statins have had a recorded drop in the amount of these fat soluble nutrients in the body. This may be a result of the reduction of LDL which is a transport vessel for a number of fat soluble nutrients. These nutrients are essential for many biological functions, and so a reduction in them may result in a number of health issues arising, from a weakened immune system to an increased amount of oxidative stress on the body.
Statins do not actually address the underlying cause of raised LDL levels, they just lower circulating LDL. The reason for raised LDL levels is usually a result of a poor diet which will not only increase the risk of cardiovascular disease, but will also increase the risk of many other diseases such as cancer. Although statins are an effective short term treatment for very high LDL levels, other lifestyle changes need to be made to prevent other diseases. Many patients do not make these dietary changes, and see LDL as enough of a lifestyle change.
Statins can reduce the risk of developing cardiovascular disease. However, there is too much uncertainty revolving around their negative health implications (such as liver damage and increasing the risk of diabetes) for doctors to be so readily prescribing them to patients. It is the opinion of many doctors that statins are currently being over prescribed, and they should be seen as a last resort to tackling cardiovascular disease instead of a primary treatment method. There are other, safer ways to protect your heart and reduce LDL level, such as cardiovascular exercise, reducing processed food intake and increasing fruits and vegetables in your diet.
Patients are also not educated enough as to the cause of raised LDL levels, and see statins as a short cut to good health, when this is not the reality. More education and care needs to be taken by both patients and doctors when considering the use of statins.