Relationship between: The Science of Nutritional Psychiatry: How Food Shapes Your Mental Health
The Science of Nutritional Psychiatry: How Food Shapes Your Mental Health. In an exclusive installment of the “Speaking of Lifestyle Psychiatry” series, Dr. Felice Jacka, OAM, director of the Food & Mood Centre at Deakin University, sits down with Dr. Alli Young to discuss the revolutionary shift in mental health care. For decades, psychiatry focused almost exclusively on the “neck up,” but Dr. Jacka’s pioneering research has proven that what we put in our mouths is as fundamental to our brains as it is to our hearts.
From the landmark SMILES trial to the impact of ultra-processed foods on the gut microbiome, this conversation outlines why diet is no longer just a “wellness fad”—it is a first-line clinical intervention for depression and anxiety. MediaXTrand report on relationship between food and mood nutritional psychiatry.
Relationship between: The Biological Link: Brain, Gut, and Inflammation
MediaXTrand report on relationship between food and mood nutritional psychiatry. The relationship between food and mood isn’t just about “feeling good” after a meal; it is rooted in complex biological pathways. Dr. Jacka identifies several key mechanisms:
- The Hippocampus: This brain region, vital for learning and memory, is often smaller in individuals with clinical depression. Research shows that high-quality diets support the expression of proteins that grow new neurons (neurogenesis).
- The Brain-Gut-Microbiome Axis: The gut microbiome breaks down fiber into metabolites that influence brain function. Ultra-processed foods (UPFs) decrease microbial diversity, whereas whole foods increase it.
- Systemic Inflammation: Poor diet triggers the immune system, leading to chronic low-grade inflammation, a known physiological correlate of Major Depressive Disorder (MDD).
Relationship between: the “SMILES” Trial: Evidence-Based Remission
MediaXTrand report on relationship between food and mood nutritional psychiatry. Dr. Jacka’s SMILES trial was the first randomized controlled trial to prove that dietary improvement can treat clinical depression.
| Study Feature | Result / Finding |
| Participants | Individuals with moderate to severe MDD. |
| Intervention | 3 months of personalised dietary support (Mediterranean-style). |
| Success Rate | 33% (one-third) achieved full remission of depression. |
| Cost-Effectiveness | The healthy diet was actually cheaper than the junk-heavy diet participants previously ate. |
| Dose-Response | The more people improved their diet, the more their depressive symptoms decreased. |
The Mediterranean Standard vs. Ultra-Processed Foods
When asked for the most powerful recommendation, Dr. Jacka points directly to the Mediterranean-style diet.
- What to Eat: A diverse range of plant foods (vegetables, legumes, fruits), whole grains, nuts, seeds, olive oil, and fish.
- What to Limit: “Discretionary” or ultra-processed foods.
- The “Bang for Your Buck” Rule: Research suggests that while adding good food is vital, dropping junk food (UPFs) may drive the fastest reduction in depressive symptoms. For every 10% reduction in UPFs, researchers saw a significant drop in clinical depression scores.
Practical Tips for Clinicians and Patients
Dr. Jacka emphasizes that nutritional psychiatry should be accessible and integrated into standard care:
- Affordability: You don’t need “organic” or “superfoods.” Frozen vegetables, tinned beans, and dried lentils are evidence-based, low-cost options.
- Multidisciplinary Care: New research (the CALM Trial) shows that lifestyle support from dietitians and exercise physiologists is non-inferior to CBT from psychologists for reducing psychological distress.
- The 15-Minute Visit: Clinicians can start by simply asking: “What does your typical breakfast or lunch look like?” or “How do you feel after eating certain foods?”
“This idea that somehow mental health exists in the head and physical health exists in the body is clearly outdated. We are a complex, tightly integrated system.” — Dr. Felice Jacka