14 DAY TRIAL // Ingesting trans-fats and saturated fats increases the risks of suffering from depression, while olive oil protects against this mental illness, concluded researchers from the universities of Navarra and Las Palmas de Gran Canaria.
Depression incidence rises every year, and today the condition affects 150 million people worldwide, being the main cause of a shorter life in countries that have a medium-to-high per capita income.
Almudena Sánchez Villegas, Associate Professor of Preventive Medicine at the University of Las Palmas de Gran Canaria and first author of the article, says that this is due “to radical changes in the sources of fats consumed in Western diets, where we have substituted certain types of beneficial fats—polyunsaturated and monounsaturated in nuts, vegetable oils and fish—for the saturated and trans-fats found in meats, butter and other products such as mass-produced pastries and fast food.”
The study involved 12,059 SUN Project volunteers, over a six-year period, and analyzed the participants' diet, lifestyle and ailments at the beginning, during, and at the end of the project.
This way the researchers confirmed that at the beginning, no one suffered from depression, but at the end, there were 657 new cases.
Among all the study participants, those with a high consumption of trans-fats, “presented up to a 48% increase in the risk of depression when they were compared to participants who did not consume these fats,” Almudena Sánchez-Villegas said.
Also, there seems to be a dose-response relationship because “the more trans-fats were consumed, the greater the harmful effect they produced in the volunteers,” according to the expert.
The interesting thing is that this research has been performed on a population with relatively low intake of trans-fats, since they represented only 0.4% of the total energy ingested by the volunteers.
“Despite this, we observed an increase in the risk of suffering depression of nearly 50%,” said Miguel Ángel Martínez-González, Professor of Preventive Medicine at the University of Navarra, and director of the team.
“On this basis, we derive the importance of taking this effect into account in countries like the US, where the percentage of energy derived from these foots is around 2.5%.”
The research team also analyzed the influence of polyunsaturated fats (abundant in fish and vegetable oils) and of olive oil on the occurrence of depression.
“In fact, we discovered that this type of healthier fats, together with olive oil, are associated with a lower risk of suffering depression,” added the researcher and director of the SUN Project.
The results of this study also confirms that in countries of the north or Europe, the incidence of this disease is greater than in the countries of the south, which are closer to a Mediterranean diet.
Trans-fats are fats present in artificial form in industrially-produced pastries and fast food, and naturally present in certain whole milk products.
The study was published in the online peer reviewed journal PLoS ONE.