What is the relationship between diet and improvement of anxiety disorders (AD) and obsessive-compulsive disorder (OCD)?

From the Guidelines

Dietary changes focusing on anti-inflammatory foods, regular eating patterns, and a gentle FODMAP diet approach can help improve anxiety and OCD symptoms, particularly in individuals with mild to moderate gastrointestinal symptoms, as supported by the most recent evidence from 2023 1. The relationship between diet and improvement of anxiety disorders (AD) and obsessive-compulsive disorder (OCD) is complex, but research suggests that certain dietary approaches can be beneficial.

• Incorporating omega-3 rich foods like fatty fish, flaxseeds, and walnuts can help reduce inflammation and support brain health.
• Including complex carbohydrates such as whole grains, legumes, and vegetables can stabilize blood sugar levels, reducing the likelihood of anxiety triggers.
• Limiting caffeine, alcohol, and refined sugars is also recommended, as these can worsen anxiety symptoms.
• Fermented foods like yogurt, kefir, and sauerkraut support gut health, which is directly linked to mental health through the gut-brain axis.
• A gentle FODMAP diet approach, which involves restricting selected FODMAPs, may be appropriate for individuals with mild to moderate gastrointestinal symptoms, as it can help reduce symptoms of anxiety and depression, although the evidence for its efficacy on psychological symptoms is limited 1. It is essential to note that while dietary changes can complement traditional treatments like medication and cognitive behavioral therapy, they should not replace these treatments.
• Medications such as SSRIs (e.g., fluoxetine 20-80mg daily or sertraline 50-200mg daily) and cognitive behavioral therapy are still the primary treatments for OCD, as supported by previous studies 1.
• Additionally, computer-assisted self-help interventions without human contact have shown promise in improving OCD symptoms, but more research is needed to fully understand their effectiveness and adherence 1.

From the Research

Relationship Between Diet and Anxiety Disorders

• The relationship between diet and improvement of anxiety disorders (AD) and obsessive-compulsive disorder (OCD) has been studied in various research papers 2, 3, 4, 5, 6.
• Studies suggest that nutrition interventions, such as the Mediterranean diet and supplementation of omega-3 fatty acids, can significantly improve symptoms of anxiety disorders 2, 3, 5.
• A systematic review of the possible mechanisms at play between omega-3 fatty acids and anxiety reduction identified four mechanisms: inflammatory response, brain-derived neurotrophic factor (BDNF), cortisol, and cardiovascular activity 3.
• A scoping review of the existing literature on anxiety disorders and nutrition identified associations between dietary factors and anxiety symptoms or disorder prevalence, including:
  • Less anxiety associated with: fruits and vegetables, omega-3 fatty acids, "healthy" dietary patterns, caloric restriction, breakfast consumption, ketogenic diet, broad-spectrum micronutrient supplementation, zinc, magnesium, selenium, probiotics, and phytochemicals 6.
  • Higher levels of anxiety associated with: high-fat diet, inadequate tryptophan and dietary protein, high intake of sugar and refined carbohydrates, and "unhealthy" dietary patterns 6.

Dietary Interventions for Anxiety Disorders

• A randomized, wait-list controlled pilot trial is being conducted to assess the feasibility and acceptability of a dietary counselling and omega-3 fatty acid supplementation intervention for adult women with generalized anxiety disorder (GAD) 2.
• The intervention is designed based on the Social Cognitive Theory and previous research on dietary constituents with evidence to support their use in the treatment of anxiety disorders 2.
• Nutritional interventions, such as avoiding artificial sweeteners and gluten, including omega-3 fatty acids and turmeric in the diet, supplementation with vitamin D, and ketogenic diets, may be considered as complementary approaches to medicating symptoms of anxiety disorders 4.

Future Research Directions

• High-quality intervention studies involving participants with anxiety disorders are warranted to demonstrate the therapeutic role of omega-3 fatty acids and other dietary interventions in anxiety disorders 3, 5, 6.
• Standardization of dosage and duration of omega-3 supplementation, more rigorous measurement of variables, effective blinding of participants, and designing experiments that test mediation are recommended for future research examining omega-3 fatty acids and anxiety 3.