Olive Oil and the Prevention of Metabolic Syndrome, Cancer, and Cardiovascular Disease
Research motivation to explore the benefits of olive oil spurred from observing low incidence rates of cancer and heart disease among people who consumed the mediterranean diet. Subsequently, further research evidence indicated its protective effects against Alzheimer’s disease. Many research studies explored the numerous health benefits of olive oil including the prevention of diabetes, hypertension, and neurodegenerative diseases, and its anti-inflammatory, anti-mutagenic, and anti-allergic properties.
Olive oil is the primary source of fat in the Mediterranean diet. EVOO has high nutritional quality and has several protective effects. Olive oil contains saturated fatty acids — stearate and palmitoleate, and polyunsaturated fatty acids — linoleate and linolenate. The health promoting components of olive oil include tocopherols, polyphenols, and carotenoids. Polyphenols are naturally bioactive and have varied chemical structure.
Health Promoting Benefits of Olive Oil
The health promoting benefits of olive oil are specifically tied to extra virgin olive oil (EVOO), which contains the highest levels of polyphenols. It has light color and delicate flavor. Unfiltered oil is preferable as it retains polyphenols of high polarity. EVOO contains several other components including flavonoids, esters, and lignans. EVOO is rich in oleic acid. Other beneficial components of EVOO are carotenoids (beta carotene, provitamin A, and lutein) and tocopherols.
Several olive oil components, oleic acid, polyphenols and many more, serve as a means to prevent chronic disease and promote antioxidant activity. Scientific evidence points at its ability to reduce the risk of type II diabetes, cardiovascular disease, hypertension, and cancer, as well as promote beneficial effects on the gut microbiota. Polyphenols also have anti-inflammatory properties and are protective against neurodegenerative diseases. Hydroxytyrosol is a polyphenol with the ability to scavenge reactive oxygen species and free radicals. Another phenolic compound, Oleuropein, is effective against several parasites and pathogens. Oleuropein inhibits platelet aggregation and protects insulin-producing beta cells against the harmful effects of cytokines. Hydroxytyrosol and Oleuropein also act as anti-cancer agents through several mechanisms including the induction of apoptosis and reduction of angiogenesis. Other protective effects of polyphenols include anti-atherogenic, anti-mutagenic, anti-allergic, and anti-thrombotic. Olive leaf extract is effective in the prevention of hypertension and acts as a diuretic and antiseptic.
Cardiovascular Disease Prevention
EVOO prevents cardiovascular disease as its antioxidant properties reduce oxidative stress which is a primary mechanism in the pathogenesis of atherosclerotic disease. Phenolic compounds in olive oil also have several cardiovascular benefits and serve as antioxidants. Olive oil reduces inflammation, triglycerides, oxidized LDL, visceral adiposity index, and malondialdehyde. It regulates endothelial dysfunction and platelet oxidative stress. It also modulates the expression of atherosclerosis-related genes. EVOO also decreases inflammatory markers, Leukotriene-B4 and Thrombohexane-B2 and reduces systolic and diastolic blood pressure.
Mechanisms of Preventing Metabolic Syndrome
EVOO positively influences lipid and plasma glucose levels. Research studies have indicated an improvement in postprandial glycemic profile in individuals with impaired glucose tolerance. The mechanism of regulating postprandial glycemia is by the up-regulation of insulin secretion. EVOO reduces insulin, glucose, triglycerides, and total cholesterol levels, while increasing HDL levels. Polyphenols inhibit the absorption and digestion of carbohydrates, which reduces the release of glucose from the liver, and stimulates its uptake in peripheral tissues. Antioxidative properties in olive oil reduce the production of advanced glycosylated products, leading to a reduction in glycemic load. A decrease in insulin secretion and increase in insulin sensitivity has beneficial effects on glycemic control. Olive oil also contributes towards weight control by modulating adipocyte gene expression profile through a reduction of oxidative stress, and deregulation of pathways involved in the development of obesity.
In context of Type II Diabetes Mellitus, EVOO has demonstrated its potential in decreasing metabolic risk factors by improving glucose metabolism and decreasing body weight. In patients with diabetes mellitus, EVOO successfully improved the glycaemic profile. Another effect of olive oil is the reduction of Nox2 activity, thereby reducing postprandial glycemia.
Olive Oil and Cancer Prevention
EVOO suppresses and prevents cancer in several ways. Oleic acid present in olive oil suppresses genes related to the expression of disease (for example, HER2 gene). This suppression affects cancer “etiology, invasion, prevention, and metastasis”. EVOO has shown to block the development of tumors even after exposure to UV. Studies have also demonstrated that a high intake of EVOO reduces the risk of breast cancer and malignant melanoma. It inhibits COX enzymes and has anti-inflammatory properties.
Therefore, olive oil has several potential beneficial effects on the overall health through multiple mechanisms of disease control and prevention. Incorporating extra virgin olive oil (EVOO) in the regular diet is a potential mechanism to reverse the detrimental effects of metabolic syndrome, cancer, cardiovascular disease, and many more conditions.
