A Randomized-controlled Pilot Study to Evaluate the Efficacy of a Fasting Mimicking Diet Added to Functional Therapy for Depression

Depression is considered as a systemic illness affecting the whole body and increasing the risk of several diseases. Several studies showed an important link between depression and inflammation. Indeed, depression is associated with the activation of peripheral and central immune-inflammatory pathways indicated by increased levels of proinflammatory cytokines, such as Interleukin-1 β (IL-1β), Interleukin-6 (IL-6), Tumor necrosis factor-α (TNFα) and Interferon-γ (IFNγ). Furthermore, depressed patients present high levels of C-reactive Protein (CRP).

Furthermore, several studies underlined the existence of a link between depression and alterations of the microbiome, as the gut microbiota is implicated as an important health determinant relevant to mental health Several psychotherapy programs have demonstrated to be effective in treating depression, such as Cognitive-Behavioral Therapy (CBT), psychodynamic approaches and mind-body approaches, such as yoga and meditation.

There is some empirical evidence suggesting that the Functional Therapy (FT) approach, that represents an integrated body-mind therapy, highlights the possibility of inducing real changes of the cognitive, emotional and psychological systems through direct body intervention. The purpose of FT for depression is to increase mood and self-esteem through several bodily, cognitive, and emotional techniques by helping depressed patients to improve the Basic Experiences of the Self (BES) altered in this disorder. Furthermore, the integrated treatment provides an overall framework to facilitate lifestyle changes reinforcing assertiveness and self-efficacy.

A considerable body of literature highlighted the role of a healthy diet for reducing the risk of depression. On the other side, a diet based on Western dietary pattern is associated with depressed mood and anxiety. The typology of diet also modulates several key biological processes that underscore mood disorders, such as brain plasticity, stress response system, inflammation, and oxidative processes. Furthermore, practicing a Western dietary pattern implicates a negative effect on our immune system, associating with higher inflammation, and food-related inflammation is associated to increased risk of depression. Indeed, high stress levels and poor diet may lead to a disruption of the Hypothalamic-Pituitary-Adrenal (HPA) axis, with consequent increasing of cortisol's level, low-grade systemic inflammation and oxidative stress.

In this regard, a specific typology of diet oriented on fasting has proved to be effective on several parameters related to health. Cheng and colleagues (2014) found that periodic prolonged fasting promote stress resistance, self-renewal, and lineage-balanced regeneration; moreover, their results showed that cycles of fasting reduced the immunosuppression and mortality caused by chemotherapy in mice. A gradual calorie restriction, mimicking fasting effects but providing all macro- and micro-nutrients on mice rejuvenated the immune system, extended longevity, bring to lowered visceral fat, reduced cancer incidence and retarded bone mineral density loss. Furthermore, the authors found that in old mice FMD cycles promoted hippocampal neurogenesis and improved cognitive performance and motor coordination. Moreover, a Fasting Mimicking Diet protocol was associated with a significant reduction of TNFα, IL-1β and IL-6, and this decrease could positively influence the mood.