Are proinflammatory cytokines involved in an increased risk for depression by unhealthy diets?

Abstract

Depression is a highly prevalent mental illness, which is associated with substantial functional impairment. Many factors, like especially genetic risk and stressful life events, are being discussed to be involved in the pathogenesis of the disease. There is also evidence that elevated levels of proinflammatory cytokines, which are frequently found in depressed individuals, could contribute to the development of the disease. Patients with metabolic syndrome also show a chronic low grade of inflammation. In addition, epidemiological studies suggest that an unhealthy dietary eating pattern, consisting of high amounts of refined grains and softdrinks, red and processed meat, fatty dairy products, and little amounts of vegetables, fruits and fish is associated with higher levels of major inflammatory cytokines, like Interleukin-6, and the acute phase C-reactive protein, even after controlling for body mass index. Furthermore, several recent studies suggest that an unhealthy diet quality is associated with an increased risk of depression. Therefore the connection between regular consumption of unhealthy foods, chronic inflammation, and increased risk for depression seems plausible.