Lead researcher, Almudena Sanchez-Villegas, University of Las Palmas de Gran Canaria, says "We wanted to understand what role nutrition plays in mental health, as we believe certain dietary patterns could protect our minds. These diets are all associated with physical health benefits and now we find that they could have a positive effect on our mental health."
"The protective role is ascribed to their nutritional properties, where nuts, legumes, fruits and vegetables (sources of omega-3 fatty acids, vitamins and minerals) could reduce the risk of depression."
Almudena Sanchez-Villegas says, "A threshold effect may exist. The noticeable difference occurs when participants start to follow a healthier diet. Even a moderate adherence to these healthy dietary patterns was associated with an important reduction in the risk of developing depression. However, we saw no extra benefit when participants showed high or very high adherence to the diets.
So, once the threshold is achieved, the reduced risk plateaus even if participants were stricter with their diets and eating more healthily. This dose-response pattern is compatible with the hypothesis that suboptimal intake of some nutrients (mainly located in low adherence levels) may represent a risk factor for future depression."