Numerous human and animal studies have shown that polyphenols, particularly hydroxytyrosol and HIDROX®, can safely and effectively improve blood cholesterol profiles and prevent the formation of plaques within the arteries (atherosclerosis). These effects could help reduce the risk of myocardial infarction (heart attack) and stroke.
In a 6-month clinical trial of HIDROX® in patients with hyperlipidemia, twice daily administration of HIDROX® was associated with a significant reduction in V-LDL cholesterol levels in trial participants (Bitler et al., 20xx). V-LDL cholesterol contains the highest amount of triglyceride fat of all cholesterol subtypes; high levels of V-LDL cholesterol can significantly raise the risk of coronary artery disease and myocardial infarction. By reducing V-LDL levels in patients, HIDROX® could significantly reduce the risk of cardiovascular mortality.
In the EUROLIVE clinical study (a major, multicentre trial conducted in five European countries), 200 healthy male volunteers received 25 ml of olive oil containing either low, medium, or high concentrations of polyphenols once a day for three weeks. High polyphenol olive oil resulted in significantly raised levels of HDL cholesterol (Covas et al., 2006). HDL levels in study participants increased by 0.045 mmol/L; previously in a separate study, a 0.026 mmol/L increase in HDL was associated with a 2-3 % decrease in heart disease risk (Gordon et al., 1989). Polyphenol-rich olive oil therefore has the potential to significantly reduce the incidence of cardiovascular mortality.
High polyphenol olive oil also invoked a significant reduction in the levels of oxidated LDL cholesterol; numerous studies have now linked oxidized LDL to the development of obstructive plaques within arteries. Oxidized LDL can enter arteries and form plaques which may constrict the flow of blood to the heart, invoke substantial tissue damage, and increase the risk of myocardial infarction and sudden cardiac death. Oxidation of LDL allows it to enter the wall of the artery where it can form plaques to obstruct blood flow. By significantly reducing levels of oxidized LDL in the body, high polyphenol content olive oil may be able to exert substantial cardioprotective effects.
Isolated hydroxytyrosol has been shown to have a direct, beneficial effect on the formation of atherosclerotic plaques in an animal model. Administration of hydroxytyrosol to rabbits for one month resulted in a prominent reduction of the size of plaques formed in the aorta; this effect of hydroxytyrosol is of significant clinical importance and could help reduce the risk of myocardial infarction and sudden death. Additionally, hydroxytyrosol resulted in a 50 % reduction in total cholesterol levels; these multiple beneficial effects of hydroxytyrosol were directly linked to the agent’s powerful antioxidant effects (Gonzalez-Santiago et al., 2006).