Anxiety and Nutrition: Why the Body Should Not Be Left Out of the Conversation

Anxiety is often treated as though it exists purely in the mind.

For many people, the standard route is familiar. They speak to their GP, describe panic, worry, racing thoughts, poor sleep, tension or a constant sense of unease, and are offered medication or talking therapy. Those approaches may help some people, and in certain situations they can be important.

What is often missed is the body.

Anxiety is not always simply a psychological problem. It can also be a physiological signal that the nervous system is under strain.

Nutrient deficiencies, blood sugar instability, inflammation, poor sleep, gut dysfunction, thyroid imbalance, alcohol, caffeine, medications, environmental exposures and chronic stress can all influence how safe or unsafe the body feels.

This does not mean anxiety is “all in your diet”. It means the brain is part of the body, and the body’s chemistry matters.

Anxiety Is a Nervous System State

Anxiety is usually described as excessive fear, worry or avoidance of perceived threat.

That word “perceived” matters. The nervous system is constantly scanning for safety or danger. When the body is well nourished, rested and regulated, it may tolerate stress more easily. When the body is depleted, inflamed, overstimulated or exhausted, the same situation may feel overwhelming.

This is why anxiety can worsen during periods of poor sleep, hormonal change, illness, dieting, alcohol use, gut flares or prolonged stress.

The mind may provide the story, but the body often provides the intensity.

The Role of Nutrients in Anxiety

The brain depends on nutrients to produce neurotransmitters, regulate inflammation, generate energy and maintain healthy nerve signalling.

Several nutrients have been associated with anxiety symptoms when levels are low or imbalanced.

Zinc

Zinc is involved in neurotransmitter balance, immune regulation, gut barrier function and inflammation control.

Low zinc status has been linked with higher levels of anxiety in several studies. Zinc is also important for hormone metabolism, thyroid function, skin health and immune resilience.

Low zinc may be more likely where there is poor intake, digestive dysfunction, high stress, heavy menstruation, restrictive diets, alcohol use or chronic inflammation.

Iron

Iron is essential for oxygen transport and energy production. It also plays a role in dopamine and neurotransmitter metabolism.

Low iron or low ferritin may contribute to symptoms that overlap with anxiety, including:

• Shortness of breath

• Palpitations

• Fatigue

• Dizziness

• Poor concentration

• Restlessness

• Low mood

• Hair shedding

• Poor sleep

  
  

This is especially relevant for menstruating women, women with heavy periods, vegetarians, vegans, people with gut issues, and anyone with inflammatory bowel conditions or poor absorption.

Some people are told they are anxious when their body is struggling to transport oxygen efficiently.

Selenium

Selenium supports thyroid hormone conversion, antioxidant defence and immune regulation.

Low selenium may affect mood indirectly through thyroid function, inflammation and oxidative stress. It is also important in autoimmune thyroid conditions such as Hashimoto’s, where anxiety-like symptoms can sometimes overlap with thyroid instability.

Magnesium

Magnesium is one of the key minerals involved in nervous system regulation.

It supports muscle relaxation, neurotransmitter balance, sleep quality, blood sugar regulation and the stress response. Low magnesium may contribute to:

• Muscle tension

• Restlessness

• Poor sleep

• Palpitations

• Headaches

• PMS symptoms

• Heightened stress sensitivity

  
  

Magnesium is depleted by chronic stress, alcohol, poor diet, high caffeine intake, blood sugar swings and some medications.

B Vitamins

B vitamins are central to brain chemistry, methylation, energy production and nervous system function.

Low B12, folate, B6, B1 or other B vitamins may contribute to symptoms such as:

• Anxiety

• Low mood

• Brain fog

• Fatigue

• Irritability

• Poor stress tolerance

• Nerve symptoms

• Sleep disruption

B12 deficiency can sometimes present with neurological and psychological symptoms before obvious anaemia appears. This is especially relevant for vegetarians, vegans, people with low stomach acid, long-term antacid use, gut disorders, coeliac disease or a history of repeated antibiotic use.

Blood Sugar and Anxiety

Blood sugar instability is one of the most common physiological drivers of anxiety-like symptoms.

When blood glucose drops too low or fluctuates sharply, the body may release stress hormones such as adrenaline and cortisol to bring it back up. This can feel like anxiety.

Symptoms may include:

• Shaking

• Sweating

• Sudden panic

• Irritability

• Feeling wired

• Heart racing

• Hunger

• Weakness

• Waking in the night

• Afternoon crashes

  
  

Many people unknowingly fuel this pattern with coffee, skipped meals, cereal, toast, pastries, sugary snacks or low-protein meals.

A protein-rich breakfast, balanced meals and fewer refined carbohydrates can make a noticeable difference for some people.

Caffeine, Energy Drinks and Stimulants

Caffeine does not create energy. It stimulates the nervous system.

For someone who is well rested, well nourished and metabolically stable, moderate caffeine may be tolerated. For someone already running on stress hormones, caffeine can push the system further into overdrive.

Coffee, energy drinks and stimulant medications can increase adrenaline-like signalling. This may worsen palpitations, shakiness, poor sleep, racing thoughts and panic sensations in susceptible people.

If anxiety is present, caffeine intake is always worth reviewing.

Alcohol and Anxiety

Alcohol is often used to relax, but it can worsen anxiety over time.

It disrupts sleep, affects blood sugar, increases oxidative stress, alters neurotransmitters and can deplete nutrients including B vitamins and magnesium.

Many people notice anxiety is worse the morning after drinking. This is sometimes called “hangxiety”, and it is not imaginary. It reflects changes in blood sugar, stress hormones, sleep architecture, hydration and neurotransmitter balance.

Gut Health and the Brain

The gut and brain are closely connected.

The gut microbiome influences immune signalling, neurotransmitter production, inflammation, vagus nerve communication and stress tolerance.

Gut issues such as bloating, constipation, diarrhoea, reflux, food reactions, SIBO, coeliac disease, inflammatory bowel disease or dysbiosis can all add to the body’s stress load.

Repeated antibiotic use may also affect the gut microbiome, which may influence mood and anxiety in some people.

This is why anxiety should not be separated from digestion. Many people with anxiety also have gut symptoms, and the two often need to be assessed together.

Gluten and Anxiety

For some people, gluten may be relevant.

In coeliac disease and non-coeliac gluten sensitivity, gluten can affect more than the gut. Some people experience neurological or psychological symptoms, including brain fog, low mood, irritability or anxiety.

This does not mean gluten is the cause of all anxiety. It means gluten should be considered in the right clinical context, especially where anxiety appears alongside:

• Digestive symptoms

• Autoimmune disease

• Thyroid problems

• Iron deficiency

• B12 or folate issues

• Migraines

• Brain fog

• Skin problems

• Fatigue

  
  

Testing for coeliac disease should be done before removing gluten if coeliac disease is suspected.

Thyroid Function and Anxiety

Thyroid imbalance can strongly affect mood and nervous system activity.

An overactive thyroid, excessive thyroid medication, thyroid autoimmunity or fluctuating thyroid hormones may contribute to anxiety, palpitations, insomnia, heat intolerance, irritability and internal tremor.

Low thyroid function can also contribute indirectly through fatigue, low mood, poor motivation, constipation, weight gain and reduced stress tolerance.

For some people, a full thyroid picture is needed rather than TSH alone.

Hormones, PMS and Perimenopause

Women often notice anxiety worsening before a period, after childbirth, during perimenopause or in menopause.

This is not a personal failing. Hormonal shifts affect neurotransmitters, sleep, blood sugar, histamine, temperature regulation and stress resilience.

PMS-related anxiety may be influenced by magnesium, B6, zinc, iron status, blood sugar balance, stress load and hormone fluctuations.

In perimenopause, anxiety can appear suddenly even in women who have never previously struggled with it. This often overlaps with poor sleep, night waking, hot flushes, palpitations and reduced stress tolerance.

Environmental Stressors

The nervous system also responds to environmental exposures.

Potential contributors may include:

• Mould exposure

• Poor indoor air quality

• Pesticides

• Heavy metals

• Food additives

• Artificial colours

• Fluoride or chlorine exposure in water

• Chemical sensitivity

These are not always the main driver, but they may add to the total load in sensitive individuals.

The Lifestyle Foundations That Matter

Supporting anxiety physiologically does not need to be complicated, but it does need to be consistent.

Helpful foundations include:

• Eating enough protein

• Avoiding skipped meals

• Reducing alcohol

• Reviewing caffeine intake

• Getting morning daylight

• Prioritising sleep

• Moving the body regularly

• Supporting magnesium and B vitamin status

• Addressing gut symptoms

• Checking iron, B12, folate, vitamin D and thyroid markers

• Reducing ultra-processed foods and additives

• Building real social connection

• Using breathwork to calm the nervous system

Deep breathing, slow walking, morning light and regular meals may sound simple, but they can be powerful when the nervous system has been running in survival mode.

What to Test

Where anxiety is persistent, worsening or appearing alongside physical symptoms, it may be helpful to investigate:

• Full blood count

• Ferritin and iron studies

• B12 and folate

• Vitamin D

• Thyroid markers, including antibodies where appropriate

• Magnesium, zinc, copper and selenium status where available

• HbA1c and fasting glucose

• Insulin where metabolic issues are suspected

• Coeliac screening

• Inflammatory markers

• Gut testing where digestive symptoms are significant

• Hormone testing where symptoms are cyclical or linked with perimenopause

Testing should always be guided by the individual’s history and symptoms.

The Bigger Picture

Anxiety can be psychological, emotional, physiological or all three.

For some people, trauma, stress or life circumstances are central. For others, the body is also sending clear signals of depletion, inflammation, hormonal change, poor sleep, gut dysfunction or nutrient imbalance.

Medication and therapy may have a place. So can nutrition, blood sugar support, gut health, mineral status, hormone assessment, sleep work and nervous system regulation.