There is a lot of evidence to show that the food you eat has a relationship to your mood. Diets that are thought to be unhealthy containing a lot of processed food seem to be mood lowering, as well as causing other long term problems. Although different countries have differing dietary patterns, the Norwegian diet, containing lots of fish and less processed food seems to cause less depression than the average diet of the UK or the USA which yields more risk of depression and anxiety.
The question remains however, what is the potential mechanism by which diet can affect mood! One physiological mechanism that links depression to diet is through the body’s own inflammatory process. Poor diet seems to cause an up-regulated inflammatory process. Depression is also linked to an up-regulated inflammatory process, whereas healthy diets down regulate the inflammatory processes. A diet rich in fruit, vegetables, meat, fish, whole grains and olive oil, such as the Mediterranean diet, is associated with lower levels of inflammatory markers and also with lower incidence of depression. Whereas a diet rich in processed foods, fried foods, refined grain, sugary products and beer was associated with higher depression levels.