Researchers from the universities of Navarra and Las Palmas de Gran Canaria in Spain have demonstrated that the ingestion of trans fats and saturated fats increase the risk of depression and that olive oil, on the other hand, protects against this condition.
The study followed 12 059 SUN Project volunteers over the course of 6 years; the volunteers had their diet, lifestyle, and ailments analyzed at the beginning of the project, over its course, and at the end of the project. The researchers confirmed that despite the fact that at the beginning of the study none of the volunteers suffered from depression, at the end of the study, 657 new cases had been detected.
Of all these cases, the participants with an elevated consumption of trans fats (fats present in artificial form in industrially produced pastries and fast food and naturally present in certain whole milk products) “presented up to a 48% increase in the risk of depression when they were compared to participants who did not consume these fats,” according to Almudena Sánchez-Villegas, associate professor of preventive medicine at the University of Las Palmas de Gran Canaria.
The study also demonstrated a dose-response relationship: the more trans fats participants consumed, the greater the harmful effect they produced. Furthermore, the researchers analyzed the influence of polyunsaturated fats (abundant in fish and vegetable oils) and of olive oil on the occurrence of depression. They found that the consumption of healthier fats and olive oil was associated with a decreased risk of depression.
The results of the study corroborate the hypothesis of a greater incidence of depression in countries of northern Europe compared to the countries of the south, where a Mediterranean dietary pattern prevails. Nevertheless, experts have noted that the incidence of the disease has increased in recent years, affecting 150 million people worldwide.
The research, which was published in the online peer-reviewed journal PLoS ONE, was conducted in a population with a low average intake of trans fats, which made up only 0.4% of the total energy ingested by the volunteers. Even so, the researchers observed an increase in the risk for depression of almost 50%. This could be an important finding for countries like the United States, where the percentage of energy derived from these foods is approximately 2.5%.