Many people have a tendency to view diet as something that's purely physical, associating the foods they eat with how they look and how much energy they have. While accurate, it doesn't paint the full picture of just how big and positive an impact healthy diets can have on overall health.

In regard to healthy diets, it's hard to dispute the effectiveness of the Mediterranean diet. The Mediterranean diet focuses on plant-based foods and, as a result, includes lots of fruits, vegetables, legumes, nuts, and olive oil. The diet is so healthy that the World Health Organization even recognizes it as a healthy, sustainable dietary pattern. Long touted for its ability to promote heart health and reduce the risk for heart disease, which the WHO notes are the No. 1 cause of death across the globe, the Mediterranean diet has also been found to protect against cancer and type 2 diabetes.

Each of those benefits makes the Mediterranean diet worthy of consideration at the very least, but the benefits of this approach to eating don't stop there. In fact, people unfamiliar with the Mediterranean diet, or even those who subscribe to it, may not realize that the diet can have a positive effect on mental wellness.

A 2015 study published in the scientific journal Ageing Research Reviews found that strong adherence to the Mediterranean diet was associated with a 40 percent reduced risk for cognitive impairment. Another study from researchers in Spain found that older adults who supplemented their Mediterranean diets with extra olive oil or nuts had a superior cognitive function, including better memory and thinking skills than those who ate low-fat diets. Reasoning, attention and language were better among the former group as well.

In addition to improving cognitive function, the Mediterranean diet also may improve mental wellness by reducing adherents' risk of developing depression. A 2013 study published in the Journal of Nutrition, Health and Aging found that people who followed the Mediterranean diet most closely were nearly 99 percent less likely to develop depression than those who followed the diet the least closely.

By MS