Cortisol and nutrition: How micronutrients, gender and lifestyle shape the stress response

Guest article by our nutrition expert Dr. Dorothea Portius

Cortisol, the most important glucocorticoid in the human body, is regulated via the hypothalamic-pituitary-adrenal axis (HPA axis). It is not only the so-called "stress hormone", but also performs central tasks in energy, immune and brain metabolism.

The release of this important hormone follows a distinct circadian rhythm: maximum concentrations in the early morning (approx. 30-45 minutes after waking up) and a continuous drop throughout the day. This natural dynamic is essential for energy, motivation and cognitive performance.

Cortisol as a component of the neuroendocrine stress response with a broad spectrum of action

What happens with chronically elevated cortisol secretion

Permanent activation of the HPA axis - for example due to long-term stress, lack of sleep, inflammatory processes or poor diet - leads to dysregulated cortisol release, e.g.b. in the form of a "flattened diurnal slope", d.h. there is no physiological drop in cortisol. Cortisol also remains elevated in the second half of the day and especially towards the evening.

This disturbed rhythm has consequences:

• Visceral obesity (increased accumulation of fat in the abdomen) and insulin resistance
• Neurocognitive disorders (e.g. reduced memory performance, concentration problems)
• Depression, irritability, anxiety
• Increased inflammatory status and immunosuppression
• Hypertension, sleep disturbances and fatigue

Gender-specific differences: cortisol does not affect everyone in the same way

Women have a higher hormonal reactivity to psychosocial stress than men - especially in social contexts or in interpersonal conflict processing. The HPA axis in women is more strongly influenced by the sex hormones (oestrogen and progesterone), which in turn modulate the glucocorticoid receptors.

Cycle-related fluctuations in the stress response:

• Follikelphase (1.–14. Cycle day): weaker cortisol response, higher stress resilience
• Luteal phase (day 15-28): Increased cortisol reactivity, emotional irritability, sleep disturbances, reduced stress resilience
• Menstruation: Increased sensitivity to pain, mood swings, magnesium loss
• Perimenopause/menopause: drop in oestrogen and progesterone destabilizes HPA axis → risk of chronically elevated cortisol, "hormone stress", inner restlessness

Men, on the other hand, often show a sympathoadrenergic-dominated stress response through an increase in heart rate and activation by noradrenaline), while cortisol-driven HPA activation tends to be flatter.

Nutrition as a key factor: cortisol influences our eating behavior - and vice versa

Stress and nutrition in imbalance

Chronically elevated cortisol levels (stress) promote unfavorable eating behavior:

• Hunger for energy-dense foods: Cortisol stimulates appetite, especially for sugar and fat ("comfort food")
• Increased calorie intake under stress: proven especially in restrictive eating women
• Decoupling of hunger and satiety due to disruption of ghrelin and leptin signals

This creates a vicious circle of stress, increased cortisol and uncontrolled eating, which can lead to weight gain, insulin resistance and metabolic syndrome in the long term.

Nutrition for cortisol regulation: which nutrients help

Diet has the potential to specifically modulate cortisol balance - both through a targeted macronutrient distribution and through the specific intake of micronutrients:

Magnesium - the natural stress blocker

Magnesium is a key anti-stress mineral that regulates the HPA axis via several mechanisms:

• Inhibits the release of ACTH in the pituitary gland (hypophysis) → Reduction of cortisol release
• Reduction of neuronal overexcitation via certain receptors (NMDA antagonism)
• Promotes parasympathetic activity → calming effect on heart rate and sleep quality
• Works synergistically with vitamin B6: improves mood and also reduces PMS-related stress symptoms in women

Good to know: Stress increases the magnesium requirement (due to higher excretion in the kidneys and increased oxidative stress). Women also lose an above-average amount of magnesium during menstruation.

Recommended intake: 300-400 mg/day (women), higher doses may be necessary in the case of increased stress, ideally in the form of organically bound magnesium (e.g. magnesium glycinate or threonate).

Magnesiumreiche Lebensmittel

• Pumpkin seeds, almonds, cashews
• Oat flakes, black beans
• Bitter chocolate (min. 75 %)
• Spinach, Swiss chard, broccoli

Dorothea Portius is a nutritionist, researcher and author

Other antistress micronutrients

Timing when eating is crucial: eating at the right rhythm supports the stress hormone balance

A disrupted and irregular eating rhythm can derail the circadian cortisol cycle.

• Early meals in particular. carbohydrate (fiber) & protein-rich breakfast mitigates the cortisol response during the day
• Late and heavy evening meals can shift cortisol and melatonin production and disrupt sleep
• Time-restricted eating in line with the natural cortisol cycle improves metabolic parameters and lowers inflammation

Conclusion on cortisol

Cortisol is not a "bad hormone", but a finely tuned regulator that helps us to respond to particular demands. However, in today's hectic and overwhelming everyday life and living environments, chronic stress is constantly present - and with it the danger of cortisol turning from a helper into a risk factor.

Nutrition is a powerful modulator of this axis. Macro- and micronutrients can help to cushion cortisol spikes, stabilize neuroendocrine systems and promote stress resilience. Magnesium stands out as a key mineral here - especially for women whose hormonal stress sensitivity is characterized by cycle phases and hormonal transitions.

Conscious handling and more mindfulness in food selection, nutritional rhythms and micronutrients is therefore not a "lifestyle issue", but an evidence-based strategy for coping with stress - preventively and therapeutically.