Much research has provided evidence of the benefits of olive oil in combating the incidence of various diseases. Here is a summary of the findings.

Cardiovascular diseases

As discussed earlier olive oil has a positive effect on cholesterol metabolism and reduces blood clotting and the aggregation of blood platelets which results in atherosclerosis and blood clotting.

Blood pressure

Regular consumption of olive oil decreases both the maximum (systolic) and minimum (diastolic) blood pressure.

Diabetes

Olive oil lowers LDL lipoproteins, improves blood sugar control and enhances insulin activity.

Immune system

The immune system comprises the ‘external’ defense such as the skin and mucous membranes and the ‘internal’ defense involving the lymph system and cells. Research shows that fatty acids in olive oil play an important role in various immune functions.

The lipid profile of olive oil is very similar to that of the human skin and like the skin can act as an inhibitor reducing the effect of the sun’s rays in speeding up ageing by generating free radicals.

The anti-oxidants and vitamins in olive oil make it a useful therapy in the treatment of acne, psoriasis and eczema.
Digestive system
Olive oil reduces the risk of reflux from the stomach as it does not reduce the tone (elasticity) of the muscular ring in the oesophagus where it opens into the stomach. 
It also slows down the release of stomach contents into the duodenum, increasing the feeling of fullness and the efficiency of digestion and absorption.
Olive oil improves the emptying of the bile duct and increases the amount of cholesterol excreted by the liver. It also prevents absorption of cholesterol by the small intestine and improves the absorption of minerals such as calcium, magnesium and iron.

It also has a mild laxative effect.

Ageing

The anti-oxidant effect of olive oil in eliminating free radicals which are the molecules involved in chronic disease and ageing.

Osteoporosis

Olive oil has been shown to have a positive effect on bone calcification and mineralisation by helping calcium absorption.

Cancer

The genetic code of each cell normally contains oncogenes which can stimulate cell proliferation. These genes are usually repressed and not active. They are sometimes activated to repair damage but in tumours they are permanently active causing uncontrolled cell proliferation. The ‘switching on’ of these genes can be done by tumour inducers causing a mutation, inducers can be chemical, physical or biological. When activated, tumour promoters help perpetuate the proliferation. Promoters can be hormones, chemicals or dietary substances.

Monounsaturated fatty acids, as found in olive oil, appear to exert a protective effect against this process. This is evidenced by the relatively low incidence of tumours in Mediterranean countries where large amounts of olive oil are consumed. However, other components of the diet and lifestyle are sure to contribute to this low incidence.

Anti-oxidants in olive oil also appear to play an important role as anti-promoters of carcinogenesis.