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

Guest article by our nutrition expert Dr. Dorothea Portius

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

The release of this crucial hormone follows a distinct circadian rhythm: peak concentrations in the early morning (approximately 30–45 minutes after waking) and a continuous decline 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 effects

What happens when cortisol secretion is chronically elevated?

Persistent activation of the HPA axis—for example, due to chronic stress, lack of sleep, inflammatory processes, or poor nutrition—leads to dysregulated cortisol release, e.g., in the form of a "flattened diurnal slope," meaning there is no physiological decrease in cortisol. Cortisol remains elevated even in the second half of the day, especially towards the evening.

This disturbed rhythm has consequences:

• Visceral obesity (increased accumulation of fat in the abdominal cavity) and Insulin resistance
• Neurocognitive disorders (e.g. reduced memory performance, concentration problems)
• Depression, irritability, anxiety
• Increased inflammatory status and immunosuppression
• High blood pressure, disorders of the sleep and exhaustion

Gender differences: Cortisol does not affect everyone the same

Women exhibit higher hormonal reactivity to psychosocial stress than men—particularly in social contexts or in interpersonal conflict resolution. The HPA axis in women is more strongly influenced by the sex hormones (estrogen and progesterone), which in turn modulate the glucocorticoid receptors.

Cyclical fluctuations in stress response:

• Follicular phase (1st–14th day of cycle): weaker cortisol response, higher stress resilience
• Luteal phase (15–28Day): Increased cortisol reactivity, emotional irritability, sleep disturbances, reduced stress resilience
• menstruation: Increased sensitivity to pain, mood swings, magnesium loss
• Perimenopause/Menopause: Decline in estrogen and progesterone destabilizes HPA axis → risk of chronically elevated cortisol, “hormonal stress”, inner restlessness

Men, on the other hand, often show a sympathoadrenergic-dominated stress response (through an increase in heart rate and activated 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 unhealthy eating behavior:

• Cravings for energy-dense foods: Cortisol stimulates appetite, especially on Sugar and fat (“comfort food”)
• Increased calorie intake during exercise: demonstrated especially in women who eat restrictively
• Decoupling of hunger and satiety by disrupting ghrelin and leptin signals

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

Nutrition for cortisol regulation: Which nutrients help?

Nutrition has the potential to specifically modulate cortisol levels – both through 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 through 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 need for magnesium (due to increased excretion in the kidneys and increased oxidative stress). Women also lose an above-average amount of magnesium during menstruation.

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

Magnesium-rich foods

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

Dorothea Portius is a nutritionist, researcher and author

Other anti-stress micronutrients

Timing when eating is crucial: Eating in a rhythmic manner supports the stress hormone balance

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

• Early meals, especially carbohydrate-rich (fiber) and protein-rich breakfasts, reduce the cortisol response during the day
• Late and heavy evening meals can delay cortisol and melatonin production and disrupt sleep
• Time-restricted eating in accordance with the natural cortisol profile improves metabolic parameters and reduces inflammation

Conclusion on cortisol

Cortisol is not a "bad hormone," but a finely tuned regulator that helps us respond to specific demands. However, in today's hectic and overwhelming everyday lives, chronic stress is constantly present – ​​and with it the danger that cortisol turns from a helper into a risk factor.

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

Conscious handling and greater mindfulness in food selection, eating rhythms and micronutrients is therefore not a “lifestyle issue”, but an evidence-based strategy for stress management – ​​preventative and therapeutic.