There’s a lot of controversy surrounding which oil to use at the moment. But, at this stage, my favourite recommendation remains Extra Virgin Olive Oil, commonly known as EVOO.
The evidence around the positive effect of EVOO on our cholesterol levels (it reduces oxidised LDL (bad cholesterol) and triglycerides and increases HDL (good cholesterol)) and therefore its beneficial effects on heart health are well known.
But there is much more to learn about the broader range of benefits that EVOO can have on a variety of other medical conditions. A lot of studies looked at EVOO and compared it to other oils, however some looked at it from the view of a Mediterranean diet; which is rich in EVOO, fresh fruit and vegetables, seafood and low in processed foods. Either way, the inclusion of EVOO is looking promising as the staple oil in our diet.
Below is a summary of the key findings:
Observational studies have showed that the use of EVOO affects where fat is stored. Looking at those who follow the traditional Mediterranean diet, they tend to have reduced waist circumferences, which can impact weight-related conditions such as insulin resistance, diabetes, metabolic syndrome and high cholesterol.
Additionally, when comparing the Mediterranean diet, a low carbohydrate diet and a generic low fat diet, researchers found that after 2 years, participants who followed the Mediterranean diet and the low carbohydrate diet had better longer term weight loss results than a traditional low fat diet. These are important findings as previous weight loss advice centred on reducing fat, however this study shows that the inclusion of EVOO within a healthy diet can assist in longer term weight loss.
The weight management benefits are thought to be two-fold; firstly, EVOO induces an increase in thermogenesis which ultimately increases overall energy expenditure, when compared to the same kilojoule content found in different types of oils. Secondly, a molecule (OEA) within EVOO acts on gut signalling in the small intestine to increase satiety and influence appetite and therefore can moderate overall energy intake.
The effect on diabetes management comes from the phenolic compounds improving insulin sensitivity, blood lipids, glucose levels and leading to a favourable relationship with insulin secretion.
One large study found that 8g (1tbsp) olive oil/day could equate to a 10% risk reduction of developing type II diabetes.
The Mediterranean diet has been linked with a decreased incidence of breast, colon and skin cancer. EVOO has a high quantity and quality of antioxidants and chemo-protective phenolic compounds that can reduce the impact of free radicals and decrease DNA oxidation.
It has been reported that 25g (3 tbsp)/day can decrease breast cancer progression by decreasing cell proliferation and differentiation.
The antioxidant ‘squalene’ is stored in all tissue but is found in highest concentration in the skin. Squalene appears to protect the skin from UV radiation and thus has a strong correlation with decreasing the incidence and severity of skin cancer. These results also are seen with observational studies highlighting the lower rates of skin cancer in Mediterranean countries that have EVOO as a staple within their diet.
EVOO has been known for its anti-inflammatory effect but its application in chronic inflammatory conditions is showing promise. The phenolic compounds within EVOO can decrease markers of inflammation such as TXB2, LTB2, COX-1 and COX-2. These particular inflammatory compounds have been linked with chronic conditions such as osteoarthritis, inflammatory bowel disease and Alzheimer’s disease. Therefore, the addition of EVOO within the diet may have beneficial effects in the prevention and management of these conditions.
There have only been a few studies looking into the effect of EVOO and blood clotting, but results indicate that phenolic compounds decrease expression of adhesion molecules that play a role in clotting and atherosclerosis. Reducing the activity of platelets and endothelial cell adhesion molecules may have a positive effect in cardiovascular disease, blood clotting and certain cancers.
Although there aren’t many significant human studies, animal studies indicate that EVOO can increase bone formation by boosting the amount of calcium that is deposited within the bone matrix. Results further indicate that the antioxidants present in EVOO could scavenge free radicals which could otherwise inhibit the activity of mature bone forming cells. Observational studies are also apparently showing that people living in Mediterranean countries, who have EVOO within a part of their normal diet, have lower rates of osteoporosis.
This exciting research into the far-reaching benefits of EVOO is changing the way we look at healthy eating. So, will you be reaching for a bottle of EVOO when cooking dinner tonight?