Two studies point to olive pomace oil as a reducer of cholesterol, insulin levels and waist circumference

Raquel Mateos Briz, senior scientist at the Institute of Food Science and Technology and Nutrition (ICTAN-CSIC) and co-author of the research, in the center's laboratories.

While virgin olive oil has been exhaustively studied, its brother, resulting from the integral use of the olive and known as olive pomace oil, did not until now have relevant and reviewed research in humans that would allow determining its effects on the health of the consumers.

The Institute of Food and Nutrition Science and Technology (ICTAN) of the Higher Council for Scientific Research (CSIC) has begun to fill this gap with two studies in people.

These point out the benefits of its intake in reducing cholesterol levels, visceral fat, waist circumference and insulin levels, aspects directly related to cardiovascular health and associated pathologies, such as diabetes and obesity.

Studies have compared the effect of consuming olive pomace oil with high oleic sunflower oil, widely used in restaurants, and with the second most consumed oil in Spain, sunflower oil.

The results showed that the product from the olive grove presents advantages that those made with the seeds do not offer.

Although it depends on many factors, on average, 20% of the olive is used to obtain olive oil in its three categories (extra virgin olive, virgin olive and olive).

The remaining 80% is alpeorujo or moist fatty pomace, made up of water, skin, stone and the oil remaining after the first crushing of the olive.

Olive pomace oil is the result of extracting that remaining oil, refining it, and mixing it with virgin.

“In short, olive pomace oil comes from olives and, therefore, it is normal for the composition to be similar.

The quality of the fat is identical, monounsaturated.

Some of the minority components are different because the olive pomace oil has been in contact with the skin, the bone and the remaining pulp”, explains Raquel Mateos Briz, senior scientist at ICTAN, co-author of the studies and member of the research group. Metabolism and Bioactivity of Phytochemicals.

Despite the grounds for this positive suspicion, the studies on this product, of which Spain is the world's leading producer with 120,000 tons of which 85% are exported, had not been transferred to people and had focused more on its nutritional potential after experiments with animals, their chemical and physical properties, as well as their behavior in frying.

The investigation presented this Thursday takes that fundamental step.

“The characteristic of these studies is that they are chronic, that is, for a time [four weeks] olive pomace oil was the only source of fat consumed by the volunteers.

Some trials had been done measuring what happens in the blood within hours of an acute intake.

But it was a specific moment.

This is the first time that a chronic study has been carried out to see the changes in the markers to be studied and which, in our particular case, were related to cardiovascular health, obesity and diabetes”, adds Mateos Briz.

More information

Science vindicates olive pomace oil

The first of the studies, published in the

concludes that olive pomace oil can improve the profile of blood lipids.

This work evaluates the effect of dietary consumption of olive pomace oil on blood lipids and other secondary risk factors for cardiovascular disease, such as blood pressure, inflammation, and the function of the endothelium (the layer that separates the tissues of the blood).

The results show a significant reduction in cholesterol known as “bad” (low intensity lipoproteins, LDL) and apoliprotein B (proteins that bind to and transport lipids in the blood).

This decrease was observed both in healthy volunteers and in those at risk of abnormalities related to high cholesterol levels.

However, the same effect was not registered after the consumption of high oleic sunflower oil.

The rest of the secondary biomarkers evaluated were not affected in any of the cases.

In the second of the studies that compared olive pomace oil with sunflower oil, collected by

and carried out on 31 volunteers with normal cholesterol levels and 37 with hypercholesterolemia, the consumption of none of the products "had statistically significant effects on the markers related to the lipid profile."

However, a decrease in visceral fat was observed and, in the participants with high cholesterol, an increase in leptin, a hormone that promotes reduced energy intake through signals of satiety in the brain.

Although the authors acknowledge the need for more studies, they do conclude that "the reduction of visceral fat after prolonged intake of olive pomace oil could contribute to improving cardiometabolic status, with a potentially positive effect on vascular tone."

“The discrepancy between one study and another [in relation to the lipid profile] is due to the fact that they are studies in humans.

Experimental animals have a very similar genetic profile and it is easier to control and systematize them.

In the case of humans, this is not the case and we do not have the same lifestyle, physical activity or dietary habits.

All these factors influence how each person responds to the intake of the studied oils”, clarifies Laura Bravo Clemente, CSIC research professor at ICTAN and co-author of the papers.

waist circumference

The third of the studies, derived from the integration of the results obtained in the two clinical trials described in the previous articles, was published in

confirmed the significant results in the reduction of total cholesterol, LDL (the "bad") and of a significant secondary factor: waist circumference.

Volunteers with normal (65) and moderately high (67) cholesterol levels consumed normal and high oleic olive-pomace or sunflower oil.

Only those who consumed the product from the olive grove obtained the main benefits.

“The decrease in waist circumference did not surprise us either because it is associated with the olive oil itself and the quality of its monounsaturated fat, with a high oleic acid content, which contributes to less abdominal fat.

It is also necessary to take into account the series of minority components of olive pomace oil that reinforce different mechanisms.

It is a very interesting marker for all subjects with a predisposition to obesity and one of the most monitored because it is associated with a high cardiovascular risk.

The results have been significant and very conclusive in both population groups, with normal cholesterol and with hypercholesterolemia”, says Mateos Briz.

These groups of participants were chosen, according to Bravo Clemente, because they are people whose cholesterol levels are normal, representing healthy consumers, or moderately high, a circumstance, the latter, which can be corrected with diet.

In this way, people with high cholesterol levels and who need a pharmacological treatment for its regulation were excluded.

The consumption of olive pomace oil has also shown beneficial behavior against type 2 diabetes mellitus, when high levels of glucose or sugar in the blood can be controlled through diet and exercise.

The results of the study show that the use of olive fat reduces insulin levels, has beneficial effects on the insulin resistance index and increases tissue sensitivity, the response of cells to the hormone and to glucose.

quantity and variety

To obtain the benefits, the average amount that must be ingested per day is 45 grams, about four tablespoons that should account for 20% of the energy provided by food, which is desirable in terms of the intake of this type of monounsaturated fat.

It is not a question, according to both researchers, of putting the consumption of one oil before another type, but of complementing them, of using each one for what supposes a better experience.

"It's like wine, you don't always drink red", exemplifies Mateos Briz.

In this way, extra virgin olive oil would be more suitable for consumption raw and in foods that require a more intense flavour, while olive pomace oil would be suitable for culinary processes where a milder taste is required.

Also for pastries, as a substitute for butter, in stews or in fried foods.

"There, olive pomace oil has unbeatable properties," defends Bravo Clemente.

The researcher adds, regarding the industrial production of sweets, where palm oil is widely used, despite providing highly saturated fats that are negative from a nutritional point of view, that studies are being carried out to use olive pomace oil.

The results of the ICTAN work coincide with others outside this center and carried out previously with mice.

This is the case of the research carried out by Carmen Claro Cala, from the Department of Pharmacology, Pediatrics and Radiology at the University of Seville, and Rosalía Rodríguez, from the International University of Catalonia.

Their study, published in the MDPI journal

, also links olive pomace oil consumption to reduced obesity, body fat, liver inflammation, and insulin resistance.

Another study, whose main researcher is Javier Sánchez Perona, a Food and Health scientist at the Institute of Fat (CSIC), pointed out that oleanolic acid, α-tocopherol and β-sitosterol, bioactive compounds in olive pomace oil, prevent the overactivation of microglia, a group of cells of the central nervous system whose main function is defensive, and reduce neuronal inflammation, related to Alzheimer's.

The works presented this Thursday have been promoted by Oriva, an interprofessional and non-profit entity in the olive pomace oil sector created in 2015 to promote knowledge and scientific studies on this product.

"We are committed to independent, rigorous and continuous research, collaborating with the main institution in our country in this field, the Higher Council for Scientific Research," said José Luis Maestro Sánchez-Cano, president of Oriva in a note from the entity.

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