Nutrition and Mental Health

Growing evidence shows that nutrition plays a key role in mental health and wellbeing. To mark Mental Health Awareness Week, Sandra Moore - CIEH Food Safety Panel member and Director of Safety & Compliance Services at Hygenisys - explores the connection and what it means in practice.

Nutrition is one of the most important drivers of mental wellbeing and performance; the food and drink that we consume not only affects our physical health, but directly influences our mood, cognitive function, how we make decisions and our productivity, in and out of the workplace.

Effects of Nutrition On Our Brain

Our brain uses approximately 20% of our daily energy intake; it is one of the most energy-demanding organs in the body. A consistent supply of good quality nutrients is required to support functionality and neurotransmitter production, neural communication, and energy metabolism.

Research has shown that:

• The quality of our diet is linked to cognitive performance, reaction time, mental processing, anxiety, and depression
• Complex carbohydrates play a key role in mood regulation and cognitive function

It is important to remember that the quality of the food we ingest determines the quality of our output.

Blood Sugar, Mood, and Decision Making

Blood glucose regulation is key on how nutrition affects mental health.

There is now recognition that ultra processed, high-sugar diets can lead to rapid spikes and crashes in blood sugar. These fluctuations are associated with:

• Reduced concentration
• Irritability and mood swings
• Impaired decision-making and impulse control
• Physiological changes in the body, e.g. inflammation, fatty liver disease

Chronic low-grade inflammation has been linked with:

• Depression
• Cognitive decline
• Fatigue
• Reduced motivation and productivity

Studies have shown that unstable glucose levels can negatively affect self-control and judgement, increasing the likelihood of poor decisions.

In the workplace, this often shows up as:

• The ‘mid-morning/afternoon slump’
• Experiencing brain fog during key meetings and workplace operations
• Reactive rather than strategic thinking
• Poor assessments of risk especially around high-risk processes
• Reduced physicality
• Emotional/irrational outbursts
• Being overwhelmed
• Poor relationships with colleagues

Impact Workplace Productivity & Performance

At an individual level:

Poor nutrition as a holistic impact, in that it affects all aspects of our lives, in how we perform at work, how we show up for our families/friends and most importantly how we show up for ourselves.

At an organisational level:

• Poor nutrition is linked to increased absenteeism and reduced output

Inadequate nutrition is estimated to cost global economies 2–3% of GDP in lost productivity

https://pmc.ncbi.nlm.nih.gov/articles/PMC6909496/

The Gut-Brain Axis

The gut microbiome plays a significant role in mental health. It influences our neurotransmitters such as serotonin; it is estimated that around 90% of serotonin is produced in our gut. While serotonin produced in the gut does not directly enter the brain, the gut strongly influences the signalling pathways involved in emotional wellbeing.

Gut bacteria also influence dopamine, GABA, and other neurochemicals involved in mood and emotional regulation.

Imbalances in gut health are associated with brain fog, low mood, and reduced cognitive performance. It is important to remember that mental wellbeing is strongly linked with digestive health and nutrition.

It is fair to say that digestive disturbances and mental health symptoms often occur together.
Supporting the Gut–Brain Axis

Research suggests that a diverse, nutrient-rich diet supports both gut and mental health.

Increase foods such as:

• Fibre-rich vegetables and fruits
• Fermented foods (e.g. kefir, sauerkraut, live yoghurt)
• Omega-3-rich foods
• Polyphenol-rich foods such as berries, herbs, green tea, and olive oil
• Protein, healthy fats, and complex carbohydrates

Reduce foods such as:

• Ultra-processed foods this is linked to brain fog and fatigue
• Refined Sugar/Sugary drinks – leads to energy crashes and mood swings
• Excess caffeine – disrupts sleep and stress management
• Alcohol

Lifestyle Changes

• Ensuring good sleep hygiene – 7-9 hours’ sleep per night
• Reducing Chronic stress
• Movement/Exercise
• Increase hydration – fruits/vegetables with a high-water content, herbal teas, water, at least two litres a day- see link below to calculate how much water required depending on body weight

https://www.gigacalculator.com/calculators/water-intake-calculator.php 

All the above may also help support microbiome balance, mental health, productivity, and improved cognitive function.

Related Research:

https://pmc.ncbi.nlm.nih.gov/articles/PMC6378305 

Nutrition & Mental Health Outcomes

Whole-food, nutrient-dense diets (e.g. Mediterranean-style, Blue Zone Diets) have been shown to improve depressive symptoms.

A randomised controlled trial Supporting the Modification of Lifestyle in Lowered Emotional States (SMILES study) demonstrated that dietary improvement significantly reduced depression severity, compared to social support and conventional methods.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3636120/ 

Practical Organisational Approaches

Employers can support mental wellbeing and workplace productivity by:

• Reducing workplace cultures that normalise burnout
• Encouraging regular breaks and meal patterns
• Improving access to nutritious food options especially in-house food offerings
• Promoting hydration awareness
• Supporting work-life balance and sleep health
• Including nutrition within wellbeing and occupational health initiatives

Small changes can produce meaningful improvements in:

• energy
• morale
• concentration and resilience

Many discussions on mental health focuses on psychology, environmental and social stressors, however it is also influenced by:

• biology
• nutrition
• inflammation
• hydration
• sleep
• the health of the gut–brain axis

If the individual/organisations want to improve:

• productivity
• decision-making
• wellbeing
• workplace safety

then nutrition must become part of the conversation.

You cannot expect high-level performance from an undernourished team.