Spend enough time in wellness corners online and you’ll come across a familiar refrain: your cortisol levels rise with age and that’s bad news for your health in body and mind.
It’s a tidy narrative. It’s also medically and scientifically wrong, or at least radically oversimplified. The truth, as usual, is more interesting and useful than the myth.
Cortisol is a steroid hormone produced by the adrenal glands, the small caps above the kidneys that help the body decide what matters during acute “stress” or threat. It is known as the body’s “primary stress hormone”.
Cortisol’s role is a lot less dramatic than the phrase suggests.
Adrenaline and noradrenaline raise the body’s fight-or-flight alarm with a surge. They are fast-acting messenger hormones that also function as neurotransmitters. Their dual identity makes them particularly potent in the body’s stress response system.
Adrenaline, also known as epinephrine, is released mainly from the adrenal glands. It triggers the classic fight-or-flight response of faster heart rate, sharper focus and quick energy release. Noradrenaline (norepinephrine) is produced in the adrenal glands and nerve endings throughout the body. It helps regulate blood pressure, attention and alertness.
Health professionals should not routinely test cortisol levels to diagnose ‘chronic stress’. Instead, they should focus on treating the risk factors for stress.
— Constance Adams, Johannesburg specialist physician
Cortisol’s work is subtle but consequential. It increases the availability of glucose and supports blood pressure by amplifying adrenaline’s effects. It modulates neurotransmission and brain circuits powerfully and temporarily quietens processes that don’t serve immediate survival. among them digestion, reproduction and long-term repair.
In this way cortisol does not trigger the fight-or-flight response but rather extends the body’s readiness to make optimum use of it. Cortisol shapes how long the body remains alert, mobilised and orientated towards danger or what it learnt to interpret as danger.
As a chemical messenger, cortisol is designed to help you:
- wake from sleep;
- mobilise energy;
- keep brain and cognitive processes sharp; and
- respond to threats, perceived or otherwise.
It follows a predictable daily rhythm: a sharp peak in the morning on waking, gentle decline through the day and a low point at night. The sleep-wake cycle also influences it.
Survival mechanism
In older people, the morning peak may not be as pronounced, and the late-night dip not as low. However, the total amount of cortisol produced over 24-hours may be unchanged. That rhythm is not a design flaw; it’s a survival mechanism.
It’s why it’s not scientifically correct to speak of cortisol levels rising simply due to age, said Johannesburg specialist physician Constance Adams.
Adams is also an academic clinical endocrinologist and lecturer affiliated with Wits University, Charlotte Maxeke Johannesburg Academic Hospital and the Wits Donald Gordon Medical Centre. She manages complex endocrine and hormone-related conditions with research focused on cortisol, diabetes and obesity.
Cortisol’s health risk lies not in rising levels but rather from the “blunting” of physiological processes, said Adams. It’s not only a function of age.
It is largely due to “declining organ and cellular function” from a myriad of contributing causes, she said. These include loss of muscle mass, increasing fat mass, chronic illness (involving heart, lung, joints and nerve issues), chronic pain, medications, alcohol and neuropsychiatric conditions such as depression and insomnia.
In adolescents eating disorders, such as anorexia and bulimia nervosa, affect cortisol levels.
If you expect a neat checklist of signs of cortisol rhythm out of synch, prepare for disappointment. Cortisol is a slippery hormone to discuss in public because it touches everything internally and explains nothing on its own
Adams and other endocrine experts internationally see the idea that cortisol simply “rises with age” as seductive because it fits a broader “cultural script”. It sees ageing as inevitable decline, stress as a modern plague and hormones as saboteurs. It builds on concern in robust research linking raised cortisol levels with inflammation, declining cognitive function and dementia diseases such as Alzheimer’s. It gives people something concrete to blame and to test.
Cortisol testing is a minefield with levels that fluctuate from one minute to the next. A single reading tells almost nothing about the underlying rhythm and can mislead patients and doctors into chasing numbers instead of causes.
Adams is unequivocal on this point. “Health professionals should not routinely test cortisol levels to diagnose ‘chronic stress’,” she said. “Instead, they should focus on treating the risk factors for stress.”
Chronic stress can elevate cortisol and adrenaline at any age, Adams said. Older adults are more vulnerable to the consequences because their physiological reserves are thinner. Frailty, the medical term for the body’s reduced ability to bounce back, compounds everything.
When the morning cortisol peak is blunted and its rhythm “flattened” the body struggles to mount a rapid response to acute illness. When the night-time dip is shallow, inflammation and metabolic disturbances creep in. The system becomes slower, less flexible and less able to adapt.
The issue is not about excess cortisol. It’s about impaired resilience at any age, Adams said. It’s why persistent cortisol elevation in adolescents tells a different story from ageing in adults.
Child development experts will tell you teens live in bodies and brains still under construction. Chronic stress distorts that development in ways that are easy to miss. Elevated cortisol can disrupt teens’ sleep, impair concentration and blunt memory. This causes a hormonal “fog” that looks, from the outside, like laziness or moodiness in adolescents.
It can drive abdominal weight gain, worsen acne and eczema, and weaken immunity, leaving teens sick more often and slower to recover. Emotionally it amplifies anxiety, irritability and emotional reactivity. It can push some teens towards withdrawal and others towards impulsive risk-taking.
None of these signs is specific to cortisol, which is precisely the problem Adams identifies.
The physiology of chronic stress hides in plain sight. It may masquerade as “typical teenage behaviour” while quietly reshaping the stress-response system itself. It can also reflect the broader pressures of a system under strain.
If you expect a neat checklist of signs of cortisol rhythm out of synch, prepare for disappointment. Cortisol is a slippery hormone to discuss in public because it touches everything internally and explains nothing on its own.
What can you do?
Here’s where the wellness industry gets it wrong. It is not possible to “bio hack” cortisol directly with “natural supplements”. No adaptogenic herbs or magic bullet pills can safely lower cortisol in ways people may imagine.
Adams is blunt on that score: “There are pathological conditions, such as Cushing’s syndrome, where a tumour is autonomously secreting unregulated amounts of cortisol. This doctors would treat and cure by reducing cortisol levels.
“There is no evidence-based role for directly modifying the level of cortisol with pharmacology (the scientific study of drugs’ effects on living systems) where cortisol is raised due to an appropriate physiological stimulus to perceived or real ‘stress’.”
The only effective approach, Adams said, is to “address the forces that disrupt the rhythm and keep the body in a state of low-grade alarm”.
In her medical book, therefore, the aim is not to “eliminate” rising cortisol levels from “stress” but to restore and support healthy rhythms.
Here are tips from Adams and other endocrine experts to support cortisol rhythms:
- Defend your sleep: deep, regular sleep is one of the most powerful levers for healthy cortisol rhythms. Aim for good “sleep hygiene”: a consistent sleep-wake schedule, a dark, cool bedroom and at least an hour, preferably more, without screen time before bed.
- Tame the sugar “rollercoaster”: high-sugar, high-carbohydrate, ultra-processed foods create blood glucose spikes and are inflammatory, forcing cortisol to step in as a biochemical firefighter. A diet rich in nutrient-dense, first-class protein, healthy fats, omega-3 fatty acids, vegetables, whole grains and fibre help mitigate cortisol’s spikes and inflammatory effects.
- Moving, but not too much: regular, daily physical activity improves how you handle stress and can lower baseline cortisol over time. Experts suggest 150-minutes of moderate activity per week. Favour brisk walking, strength training, moderate cardio exercise over endless, high-intensity sessions. Remember, chronic over-training with poor recovery keeps cortisol high.
- Pop the “nature pill”: 20 to 30 minutes in close touch with nature, such as walking barefoot on sand or sitting on the grass, can lower cortisol levels for lengthy periods.
- Daily “off switches”: practices such as slow or “box” breathing (inhaling, holding, exhaling for four seconds each), meditation, prayer and real-world social connection are not “soft” extras. They are physiological interventions that sustain healthy cortisol rhythms.
- Work with doctors on medications: steroid medications can be life-saving but long-term high doses mimic cortisol excess and carry serious side-effects. Do not stop these drugs abruptl. Discuss the lowest effective dose, tapering plans, bone and metabolic protection and safer alternatives for long-term control.
Adams stressed cortisol is not the enemy; it is your body’s messenger. When the message is clear, brief and followed by physical and mental safety, the stress hormone becomes what it was always meant to be: a finely tuned survival tool, not a slow-motion, health catastrophe in waiting.
