Olive oil and cardiovascular diseases
Cardiovascular diseases are the top cause of death in the industrialised world. A host of studies have documented that arteriosclerosis is closely linked to eating habits, lifestyle and some aspects of economic development. The progression of arteriosclerosis depends on many factors: the most important ones are high blood cholesterol, high blood pressure, diabetes and cigarette smoking.
"… The lowest rates of death from coronary heart disease are currently recorded in the countries where olive oil is virtually the only fat consumed."
Professor Francisco Grande Covián
What is arteriosclerosis?
Arteriosclerosis is the condition in which cholesterol-rich patches (known as atheromas) deposit on the walls of the arteries. This stops blood from reaching the tissues and obstructs the functioning of vital organs, such as the heart and brain.
What are its consequences?
When the heart is affected, arteriosclerosis causes angina and heart attack and it increases the risk of sudden cardiac death. When the brain is attacked, cerebral thrombosis occurs, leading to muscular paralysis, loss of cognitive capacity and the risk of dementia. The aorta and leg arteries may also be damaged, causing pain and difficulty in walking and the risk of necrosis and gangrene.
When a fatty patch bursts, for instance because of a rise in blood pressure, the small arteries in the patch also burst. This triggers a response where certain cells found in blood, known as platelets or thrombocytes, join together to form a thrombus or blood clot.
The blood clot travels through the arteries, but when it is larger than the vessel it causes blockage. Because blood cannot get through, the tissue or organ dies.
Olive oil and arteriosclerosis
It has been demonstrated that olive oil has an effect in preventing the formation of blood clots and platelet aggregation. It has been observed that by avoiding excessive blood coagulation, olive-oil-rich diets can attenuate the effect of fatty foods in encouraging blood clot formation, thus contributing to the low incidence of heart failure in countries where olive oil is the principal fat consumed.
What is cholesterol?
Cholesterol is a fatty substance contained in foods of animal origin. Diets containing a large amount of animal fats raise blood cholesterol level, which is one of the chief risk factors of cardiovascular disease.
Fats (triglycerides) and cholesterol are transported in the blood by lipoproteins. The cholesterol bound to low-density lipoproteins [very low-density lipoproteins (VLDL) and low-density lipoproteins (LDL)] is atherogenic, damaging the vessel walls. In subsequent stages, this may lead to acute heart attack. Such cholesterol is known as "bad cholesterol". In contrast, the cholesterol bound to high-density lipoproteins (known as HDL-cholesterol) is called "good cholesterol" because it provides protection against the onset of cardiovascular diseases. The high-density lipoproteins remove free cholesterol from the cells, then esterifying it and transporting it to the liver where it is eliminated with bile.
Olive oil and cholesterol
Olive oil lowers the levels of total blood cholesterol, LDL-cholesterol and triglycerides. At the same time it does not alter the levels of HDL-cholesterol (and may even raise them), which plays a protective role and prevents the formation of fatty patches, thus stimulating the elimination of the low-density lipoproteins.
The beneficial effect of olive oil consumption with regard to cardiovascular disease has been demonstrated in primary prevention, where it reduces the risk of developing the disease, and in secondary prevention, where it prevents recurrence after a first coronary event.
At present, research is revealing the effectiveness of the Mediterranean diet in the prevention of secondary coronary events and the positive influence of olive oil on the depression associated with such events and on mood. These findings are very important in view of the high incidence of depression in the modern-day world and the great risk it poses in recurrent heart disease.