Guest article by our nutrition expert Dr. Dorothea Portius
Cortisol, the most significant 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 central roles in energy, immune, and brain metabolism.
The release of this important hormone follows a pronounced circadian rhythm: maximum concentrations in the early morning (about 30–45 minutes after waking up) 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 wide range of effects
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Glucose metabolism |
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Immune system |
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Central nervous system |
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Cardiovascular System |
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What happens with chronically elevated cortisol release?
A permanent 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.B. in the form of a "flattened diurnal slope", d.h. there is no physiological drop in cortisol. Cortisol remains elevated in the second half of the day and especially in 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 disorders
- Increased inflammatory status and immunosuppression
- High blood pressure, sleep disorders and exhaustion
Gender-specific differences: Cortisol does not affect everyone equally
Women exhibit a higher hormonal reactivity to psychosocial stress than men – especially in social contexts or in interpersonal conflict resolution. The HPA axis of women is more strongly influenced by sex hormones (estrogen and progesterone), which in turn modulate the glucocorticoid receptors.
Cycle-related fluctuations in stress response:
- Follicular phase (1st–14thCycle day): weaker cortisol response, higher stress resilience
- Luteal phase (Day 15–28): Increased cortisol reactivity, emotional irritability, sleep disturbances, decreased stress resilience
- Menstruation: Increased sensitivity to pain, mood swings, magnesium losses
- Perimenopause/Menopause: Decrease in estrogen and progesterone destabilizes HPA axis → risk of chronically elevated cortisol, "hormonal stress," inner restlessness
Men, on the other hand, often show a sympathetic-adrenaline dominated stress response through an increase in heart rate and activated by norepinephrine, while the 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:
- Cravings for Energy-Dense Foods: Cortisol Stimulates Appetite, Especially for Sugar and Fat (“Comfort Food”)
- Increased Caloric Intake Under Stress: Proven Especially in Restrictively Eating Women
- Decoupling of Hunger and Satiety Signals Due to Disruption of Ghrelin and Leptin Signals
This Creates a Vicious Cycle of Stress, Elevated Cortisol, and Uncontrolled Eating, Which Can Lead to Long-Term 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 central anti-stress mineral that regulates the HPA axis through several mechanisms:
- Inhibits the release of ACTH in the pituitary gland → Reduction of cortisol release
- Reduces neuronal hyperexcitability through specific receptors (NMDA antagonism)
- Promotes parasympathetic activity → calming effect on heart rate and sleep quality
- Works synergistically with Vitamin B6: Improvement of mood and also reduction of 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 above-average amounts of magnesium during menstruation.
Recommended intake: 300–400 mg/day (women), higher doses may be necessary under increased stress, ideally in the form of organically bound magnesium (e.g., magnesium glycinate or threonate).
Magnesium-rich foods
- Pumpkin seeds, almonds, cashews
- Oatmeal, black beans
- Dark chocolate (min.75 %)
- Spinach, Swiss chard, Broccoli
Dorothea Portius is a nutritionist, researcher, and author
Other stress-relieving micronutrients
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Nutrient |
Effect |
Food |
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Vitamin C |
Suppression of cortisol spikes Antioxidant effect |
Bell pepper, Broccoli, Sea buckthorn, Black currants |
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B vitamins (z.B.B6, B1) |
Cofactors of neurotransmitter synthesis such as serotonin &and dopamine Reduction of mental exhaustion |
Whole grains, legumes, eggs |
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Omega-3 fatty acids (DHA &and EPA) |
Anti-inflammatory effects Reduction of excessive cortisol reactions |
Salmon, herring, algae and fish oil; precursors: flaxseed, rapeseed oil |
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Tryptophan |
Starting substance of serotonin, mood regulation |
Turkey, chicken, eggs, sesame, soy |
Polyphenols (z.B.Catechins, flavonoids) |
anxiolytic and reduction of tension states, antioxidative effects in the nervous system |
berries, dark chocolate, green tea |
Timing when eating is crucial: rhythmic eating supports the stress hormone balance
A disturbed and irregular eating rhythm can disrupt the circadian cortisol cycle.
- early meals, especiallyCarbohydrate-rich (fiber) &and protein-rich breakfast mitigates the cortisol response during the day
- Late and heavy evening meals can shift cortisol and melatonin production and disturb sleep
- Time-restricted eating in accordance with the natural cortisol rhythm improves metabolic parameters and lowers inflammation levels
Conclusion on cortisol
Cortisol is not a "bad hormone," but a finely tuned regulator that helps us respond to special demands. However, in our hectic and overwhelming daily lives, chronic stress is constantly present – and with it the risk that cortisol becomes a risk factor instead of a helper.
Nutrition is a powerful modulator of this axis.Macro and micronutrients can help cushion cortisol spikes, stabilize neuroendocrine systems, and promote stress resilience. Magnesium stands out as a key mineral – especially for women, whose hormonal stress sensitivity is shaped by cycle phases and hormonal transitions.
A conscious approach and more mindfulness in food selection, dietary rhythms, and micronutrients is therefore not a "lifestyle topic," but an evidence-based strategy for stress management – both preventive and therapeutic.
