The world is more and more competitive, and many people live on constant alert. This state activates a system the body designed to protect us, the stress axis. When it stays on for too long, anxiety, sleep changes, tiredness, trouble concentrating and a higher risk of depression can appear. This guide explains the mechanism and how to care for it day to day.
In short
- Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, which releases adrenaline and cortisol. That is useful in the short term and wearing if it becomes chronic.
- The same event affects people differently: genetics, support network and coping strategies make a difference.
- “Adrenal fatigue” is not a recognized diagnosis: persistent tiredness needs investigation.
- Food, sleep, movement and psychotherapy are part of care, and do not replace treatment when there is anxiety or depression.
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How the body responds to stress
Faced with a physical or psychological stressor, the brain triggers two responses:
Fast response: fight or flight
The sympathetic nervous system releases adrenaline and noradrenaline, which speed up the heart, raise blood pressure and oxygen intake and mobilize glucose and fats to fuel the muscles. It is what helps you react to immediate danger.
Slower response: the HPA axis
The hypothalamus releases CRH, which stimulates the pituitary to release ACTH. ACTH acts on the cortex of the adrenal gland, which produces cortisol, the main human glucocorticoid. Cortisol keeps glucose available, regulates inflammation and later helps switch the stress response off.
The hypothalamus also helps control energy, appetite, weight, fluid balance, sleep, blood pressure and temperature. That is why stress can show up in so many ways.
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When stress is constant
The system was made to switch on and off. When stress is prolonged and the person cannot recover, the axis can work in a dysregulated way. Among the effects described:
- Worse sleep and difficulty relaxing.
- A higher risk of anxiety disorders and depression.
- Impaired concentration, memory and performance in study and work. In studies, chronic stress and depression have been linked to changes in brain areas such as the hippocampus.
- More craving for sweets and high-calorie food, and a tendency to gain abdominal fat.
- Higher blood pressure and blood glucose.
- Digestive changes, such as pain, bloating, diarrhea or constipation, through the gut-brain connection.
Not everyone reacts in the same way. Genetics, history of trauma, support network, health conditions and coping ability determine how much stress affects us. Feeling overwhelmed is not weakness.
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And “adrenal fatigue”?
The term is widely used to explain tiredness, low mood and lack of energy, but the adrenal glands do not “burn out” from stress. Adrenal fatigue is not recognized as a diagnosis by endocrinology societies, and studies do not support the idea.
What does exist
Real adrenal diseases, such as adrenal insufficiency (low cortisol) and Cushing's syndrome (high cortisol), which have specific diagnosis and treatment. There is also dysregulation of the stress axis, in which the response to cortisol and hormones can be altered, and this relates to tiredness, anhedonia and low mood.
Persistent tiredness
It deserves investigation: anemia, thyroid changes, vitamin deficiencies, sleep apnea, depression and other conditions need to be assessed. Avoid supplements “for the adrenals” without guidance.
If an adrenal disease is suspected, such as intense weakness, weight loss, dizziness, low blood pressure, weight gain with stretch marks or hard-to-control high blood pressure, an endocrinologist should be consulted.
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Anxiety and depression: when to seek help
It is normal to feel anxiety and sadness in hard times. It is worth seeking evaluation when symptoms are intense, last for weeks, or get in the way of work, sleep and relationships:
- Excessive worry that is hard to control, tension, irritability and palpitations.
- Depressed mood, loss of interest and pleasure (anhedonia), guilt and hopelessness.
- Changes in sleep and appetite, tiredness and difficulty concentrating.
- Panic attacks, intense fear of social situations or avoidance of activities.
Treatment may include psychotherapy, medicines and lifestyle changes, according to the psychologist's and doctor's evaluation. Nutrition supports care but does not replace it.
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Food that supports the brain
A good-quality eating pattern is linked to fewer depression symptoms. In a clinical trial (SMILES), adults with depression who received nutrition support to adopt a Mediterranean-style diet had a greater improvement in symptoms than the comparison group.
Mediterranean pattern
Vegetables, fruit, legumes, whole grains, olive oil, nuts and fish, with fewer ultra-processed foods, sugar and processed meats.
Stable blood sugar
Regular meals, with protein and fiber, help avoid glucose spikes and drops that worsen irritability, anxiety and sugar cravings.
Omega-3, magnesium and B vitamins
Fish, seeds, nuts, leafy greens, eggs and legumes are sources. Omega-3 with EPA predominance has modest results as an add-on in treating depression. Deficiencies of B12, folate, iron, zinc, magnesium and vitamin D should be investigated with tests.
Caffeine, alcohol and sugar
Too much caffeine can increase anxiety and disrupt sleep. Alcohol worsens sleep and mood in the medium term. Cut back, especially in the afternoon and evening.
Gut and microbiome
Brain and gut communicate all the time. Fiber, varied vegetables and well-tolerated fermented foods favor a healthy microbiome. Probiotics have variable results and are not for everyone.
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Habits that lower the alert
Physical exercise
It is one of the tools with the best evidence for reducing anxiety and depression symptoms. Start with what is possible, such as walking, and build up gradually.
Sleep
Regular schedules, low light and screens at night, and caffeine only in the morning help regulate cortisol. Poor sleep and stress feed each other.
Breathing, meditation and relaxation
Slow breathing, mindfulness, yoga and muscle relaxation lower sympathetic activation. A few minutes a day already help.
Connection and limits
Keeping bonds, asking for help, setting aside time for leisure and setting limits at work protect emotional balance.
Psychotherapy
Cognitive behavioral therapy and other approaches have good evidence in anxiety and depression and can be combined with nutritional care.
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Supplements and herbal remedies
Some supplements are studied for mood and anxiety, such as omega-3, magnesium, vitamin D and some herbs. Benefit varies, and the choice should be based on tests and the professional's evaluation.
Herbal remedies such as St John's wort interact with antidepressants, birth control and other medicines, and can be dangerous. Tryptophan, 5-HTP and SAMe can also interact with antidepressants. Do not use them on your own, and do not stop medicines without guidance.
Caring for the mind is also caring for the body
In the consultation, I assess your diet, tests, sleep, routine and gut health to build an individualized plan that supports your balance, in partnership with your psychologist, psychiatrist or doctor.
Dra. Daniely Catharino TooleyClinical, functional and orthomolecular nutritionist · CRN3/6794
References (5)+
- McEwen. Physiology and neurobiology of stress and adaptation: central role of the brain. Physiol Rev, 2007.
- Jacka et al. A randomised controlled trial of dietary improvement for adults with major depression (the SMILES trial). BMC Med, 2017.
- Lassale et al. Healthy dietary indices and risk of depressive outcomes: a systematic review and meta-analysis of observational studies. Mol Psychiatry, 2019.
- Cooney et al. Exercise for depression. Cochrane Database Syst Rev, 2013.
- Cadegiani & Kater. Adrenal fatigue does not exist: a systematic review. BMC Endocr Disord, 2016.
Educational content for adults. This guidance does not replace an individual consultation, diagnosis or treatment.