Nutrition and Mental Health

While the link between nutrition and physical health is well established, its impact on mental health has only recently gained broader recognition. Mental health disorders are complex and influenced by a range of factors, including genetics, gender, stress, social support, substance use, and socioeconomic status. However, emerging research now identifies diet as a key factor affecting mood, behaviour, and mental wellbeing. 

Poor nutrition can contribute to both the development and persistence of mental health conditions such as depression and anxiety. Addressing dietary factors – whether by correcting nutrient deficiencies, improving overall diet quality, or optimising gut health is now considered an important component of psychological and psychiatric care. 

Key Nutrients for Mental Health 

Several nutrients play critical roles in brain function and emotional wellbeing. Deficiencies in these can disrupt neurotransmitter production and brain chemistry, contributing to low mood, anxiety, and cognitive difficulties. 

Vitamins & Minerals 

Iron: Supports energy production and oxygen transport. Low levels are linked to fatigue and low mood. Sources: red meat, poultry, lentils, tofu, spinach. 

Vitamin D: Regulates mood and immune function; deficiency is associated with depression. Sources: fatty fish, eggs, fortified dairy, sunlight. 

B Vitamins: Crucial for neurotransmitter synthesis and energy metabolism; deficiencies are linked to depression and cognitive decline. Sources: whole grains, leafy greens, meat, eggs, legumes. 

Amino Acids 

Tryptophan: Precursor to serotonin (“the feel-good chemical”). Sources: turkey, chicken, eggs, cheese, soy, seeds. 

Tyrosine and Phenylalanine: Precursors to dopamine and norepinephrine, which influence motivation, attention, and stress response. Sources: meat, dairy, soy, eggs, legumes, nuts. 

Healthy Fats 

Omega-3 Fatty Acids: Support neurotransmitter function, reduce inflammation, and are linked to lower rates of depression and anxiety. Sources: oily fish, flaxseeds, chia seeds, walnuts. 

Prebiotics and Probiotics 
The gut and brain are closely connected. A healthy, diverse gut microbiome supports neurotransmitter production and reduces inflammation; both of which are crucial for mental health. Diets high in fibre, prebiotics, and fermented foods (e.g., yoghurt, sauerkraut, kimchi) can support gut health. 

Evidence-Based Dietary Patterns for Mental Health 

Focusing on whole dietary patterns, rather than isolated nutrients, can have a profound impact on mental wellbeing. 

Mediterranean Diet 
 
Emphasises vegetables, fruits, whole grains, legumes, lean proteins, nuts, seeds, and olive oil, with minimal processed foods. The SMILES trial (The SMILEs Trial | Food and Mood Centre) demonstrated its effectiveness in reducing depression symptoms when combined with dietary support. 

Plant-Based Diets 
 
Prioritise plant foods, legumes, whole grains, nuts, and seeds. While linked to a lower risk of depression, they require careful planning to prevent deficiencies in vitamin B12, iron, and omega-3s. 

DASH Diet 
 
Focuses on vegetables, fruits, whole grains, lean proteins, and low-fat dairy. Associated with lower rates of depression and improved brain health. 

Note: Plant-based diets need special attention to ensure adequate intake of B12, iron, and omega-3 fatty acids: nutrients essential for mood and cognition. 

Dietary Patterns That May Harm Mental Health 

Certain dietary habits may negatively impact mood and mental wellbeing: 

• Ultra-processed foods (UPFs): Associated with increased risk of depression and anxiety. 
• High glycaemic index (GI) diets: Can cause mood swings and depressive symptoms. 
• Low protein/low tryptophan intake: Can reduce serotonin levels. 
• Excessive sugar and refined carbohydrates: Linked to poor mood and perturbed gut microbiome. 

How a Dietitian Can Help 

A dietitian can: 

• Identify nutrient deficiencies affecting mental health. 
• Develop personalised, balanced nutritional guidance. 
• Guide you in following evidence-based diets like the Mediterranean or DASH. 
• Help manage changes in appetite or nutrient absorption due to medications. 
• Support plant-based eaters in meeting essential nutrient needs. 
• Collaborate with your healthcare team for a holistic approach to mental wellbeing. 

While nutrition is not standalone in the care of mental health conditions, it can play a powerful supportive role. By addressing nutrient gaps, improving diet quality, and developing sustainable eating patterns, individuals can meaningfully enhance mood, cognition, and overall well being, especially with the guidance of a qualified dietitian. 

Key Takeaways 

• Nutrition directly affects brain chemistry, mood, and cognition. 
• Deficiencies in iron, vitamin D, B vitamins, amino acids, and omega-3s can impair mental health. 
• Whole, nutrient-rich diets like the Mediterranean and DASH patterns support emotional wellbeing. 
• Plant-based diets can be effective but require careful nutrient planning. 
• Diets high in ultra-processed foods and refined carbohydrates may worsen mood disorders. 
• A dietitian can offer personalised support to optimise nutrition and mental wellbeing. 

Need Support with Nutrition and Mental Health?
If you’re navigating anxiety, depression, or simply want to improve your emotional wellbeing through nutrition, our experienced dietitians at With Grace Therapy can help. We offer personalised, evidence-based support to help you feel better from the inside out. We’re here to support your journey to better mental and physical health.