It's Not Just Stress. It's a Loss of Biological Flexibility.

Why do I feel exhausted even after sleeping eight hours?

Maybe the problem isn't a lack of sleep.

Maybe your body never truly switches out of survival mode.

We tend to think of stress as simply feeling nervous.

Science tells us it's far more complex than that.

Stress is a biological response that has enabled humans to survive for millions of years. Without it, we would never have escaped predators, searched for food or reacted to danger.

The problem isn't activating this response.

The problem is remaining in it day after day.

In this article, we'll answer questions you've probably never asked yourself about your nervous system and explain why it may be responsible for many symptoms that we have come to accept as "normal".

Is Stress Always Bad?

No.

In fact, if you never experienced stress, that would be a problem.

Stress helps us react, learn and adapt.

When it's short-lived, it can even improve both physical and mental performance. This beneficial type of stress is known as eustress.

When our ancestors had to escape from predators, the body activated an extraordinarily efficient survival programme:

  • Heart rate increased.
  • Glucose was rapidly released into the bloodstream.
  • Blood pressure rose.
  • Energy was redirected towards the muscles and the brain.

All of this made survival possible.

The problem was never the activation of this response.

The problem begins when the alarm remains switched on for weeks, months or even years.

Our bodies were never designed to live in a permanent state of alert. When stress becomes chronic and starts pushing the body towards disease, it is known as distress.

So... What Happens Inside My Body When I'm Stressed?

Imagine your brain detects a threat.

It doesn't matter whether it's a lion...

An email from work.

An argument.

Or simply constantly thinking, "I can't keep up."

Your brain interprets it as danger.

And immediately activates an emergency response.

Many discussions about stress focus almost exclusively on cortisol.

But the story is far more complex.

Today we know that chronic stress simultaneously affects multiple systems throughout the body:

  • The autonomic nervous system.
  • The immune system.
  • Energy metabolism.
  • The gut microbiota.
  • Vascular function.
  • Biological ageing processes.

When this happens, several important functions are no longer prioritised:

  • Digestion.
  • Cellular repair.
  • Parts of the immune system.
  • Memory.
  • Fertility.

It makes perfect sense.

If you were running away from a predator, your body wouldn't waste energy repairing tissues. It would invest every available resource in keeping you alive.

That's why one of the most common consequences of chronic stress is that many "non-essential" repair processes slow down, including those affecting your hair, skin, hormones and digestive system.

This may result in:

  • Weak hair and brittle nails.
  • Hormonal imbalances.
  • Dry skin.
  • Poor digestion.
  • Reduced fertility.

Does My Brain Know the Difference Between a Real Threat and an Imagined One?

Not always.

And this is one of the most fascinating discoveries in neuroscience.

Spending hours imagining a difficult conversation.

Expecting something to go wrong.

Constantly anticipating problems that haven't even happened yet.

All of these situations can trigger physiological responses remarkably similar to those caused by genuine danger.

That's why many people finish the day completely exhausted, even when "nothing actually happened".

Their bodies have spent the entire day preparing for threats that never arrived.

What Does It Mean to Have a Dysregulated Nervous System?

It doesn't necessarily mean feeling anxious all the time.

In many cases, it goes completely unnoticed.

You may recognise yourself if you...

  • Reply to WhatsApp messages immediately, even when they are not urgent.
  • Eat too quickly, even when nobody is waiting for you, barely chewing or paying attention to your food.
  • Feel uncomfortable with silence.
  • Always seem to be in a hurry.
  • Clench your jaw without even noticing.
  • Feel guilty whenever you rest.

These aren't personality flaws.

They are behaviours that may reflect a nervous system that has spent too long operating in survival mode, a condition known as hypervigilance.

Why Is Stress Linked to Metabolic Diseases?

Because the body expects movement whenever it detects danger.

Thousands of years ago, stress always required physical action: running away from predators, hunting or climbing trees.

Today, however, we experience stress sitting in front of a screen.

Cortisol and blood glucose rise, but our muscles never use that energy because we don't move.

Here's a simple tip: whenever you feel stressed, move your body. Even ten squats or ten jumping jacks can help complete the biological response your body was designed for.

Can a Dysregulated Nervous System Accelerate Ageing?

This is one of the most exciting questions currently being explored by science.

For many years, we believed ageing began exclusively inside our cells.

Today, some researchers are proposing a different perspective.

What if part of the ageing process actually begins much earlier?

What if the balance between the sympathetic nervous system (survival mode) and the parasympathetic nervous system (repair mode) is one of the key regulators of biological ageing?

This hypothesis brings together research on inflammation, metabolism, immunity and tissue repair, and may help explain why chronic stress is associated with many age-related diseases.

That said, scientific rigour is important. This is a highly promising model, but more research is still needed before firm conclusions can be drawn.

What Does It Mean to "Train" Your Nervous System? (Neuromodulation)

It doesn't mean eliminating stress.

That would be impossible.

Training your nervous system means improving its ability to change states.

To activate when necessary.

And to return to a calm, restorative state once the danger has passed.

To naturally alternate between the sympathetic and parasympathetic nervous systems.

We could describe this as physiological flexibility.

And it may be one of the best indicators of long-term health.

Keep reading to discover practical strategies you can start using today.

What Can I Do Starting Today? Creating Moments of Calm and Supporting Neuromodulation

Current scientific evidence particularly supports the following habits:

  • Keep regular sleeping hours: avoid making irregular sleep schedules another source of stress. Going to bed and waking up at the same time each day helps regulate your brain and your body's internal clock.
  • Expose yourself to natural light in the morning and again around sunset: respecting your circadian rhythm helps your body feel safe and balanced.
  • Walk between 10,000 and 12,000 steps every day and stay physically active: it's not enough to exercise for one hour and remain sedentary the rest of the day. Park further away, take the stairs, avoid lifts whenever possible and add movement throughout your daily routine.
  • Maintain meaningful social relationships.
  • Practise slow breathing for a few minutes every day: you don't need to meditate for an hour. Simply taking a few moments to perform three slow, deep breaths can already make a difference.
  • Look towards the horizon: interrupt your work for a few moments each day and focus your eyes on a distant point instead of nearby objects. This feeling of visual depth helps calm the brain and may also benefit eye health.
  • Follow a diet rich in fruit, vegetables, legumes, fibre, omega-3 fatty acids and polyphenol-rich foods. We'll explore this in the next section.

Other strategies, such as diaphragmatic breathing, heart rate variability training, spending time in nature and certain nutritional supplements, have shown promising results in specific contexts and continue to be investigated.

However, none of these healthy habits should become another source of pressure. If they turn into another obligation on your to-do list, they may actually increase your overall stress burden instead of reducing it.

What If Trying to Follow "Healthy Habits" Causes Me More Stress Than Well-Being?

You're not alone.

This is known as the wellness paradox.

Many people feel guilty when they skip a workout.

Or when they enjoy a slice of cake at a celebration.

Or when they don't reach 10,000 steps.

Or when they can't find time to meditate.

They start believing they're "doing it wrong".

But taking care of your health isn't about being perfect.

It's about building habits that you can maintain without becoming another burden.

A healthy lifestyle stops being healthy when it creates constant anxiety.

Our bodies were never designed to function perfectly every single day.

They are incredibly adaptable.

What they truly need is a balance between periods of activation and periods of recovery.

It doesn't really matter if one night you sleep badly.

Or if you exercise less for a week.

Or if you enjoy a special meal.

What truly matters is the overall pattern you maintain over months and years.

Health isn't built on perfect decisions.

It's built on good enough decisions repeated consistently over time.

Instead of asking yourself:

Am I doing absolutely everything I can to stay healthy?

It may be far more helpful to ask:

Does the way I'm taking care of myself bring me peace... or is it creating even more stress?

If the answer is the latter, you probably don't need more healthy habits.

You need to simplify.

Sometimes taking care of your nervous system doesn't mean doing more.

It means doing less.

  • Go to bed 30 minutes earlier.
  • Take a walk without looking at your phone.
  • Eat more slowly.
  • Accept that missing one workout isn't a failure.
  • Enjoy a meal with friends without feeling guilty.

Well-being should never become another obligation.

It should be the place you return to in order to recharge.

The goal isn't to create a perfect routine.

The goal is to build a life where taking care of yourself doesn't become another source of stress.

Is Sleeping Eight Hours Always Enough?

Not necessarily.

Sleep quality is just as important as sleep duration.

If you suffer from sleep apnoea or frequent sleep interruptions, temporary hypoxia (reduced oxygen levels) can occur, which also increases cortisol production.

That's why it's possible to sleep eight hours and still wake up feeling exhausted, with your body remaining physiologically stressed.

Is There a Diet That Can Help Regulate the Nervous System?

Yes.

But probably not in the way you imagine.

There are no foods that simply "eliminate stress".

What does exist are dietary patterns that promote a healthier metabolic and immune environment, helping reduce neuroinflammation, which itself can become another stressor for the brain.

Which Dietary Pattern Has the Strongest Scientific Evidence?

Until recently, the Mediterranean diet received most of the attention.

However, a large prospective study published in 2025 compared ten different dietary patterns in almost 170,000 people and found that the MIND Diet showed the strongest association with a lower risk of dementia, stroke, depression and anxiety, all conditions closely linked to neuroinflammation.

It's important to remember that this was an observational study. It shows associations rather than proving cause and effect.

Nevertheless, it provides strong evidence that overall dietary quality plays an important role in brain health.

What Makes the MIND Diet Different?

It's not a miracle diet.

It combines the strongest features of the Mediterranean Diet and the DASH Diet, while placing greater emphasis on foods specifically associated with brain health.

  • Green leafy vegetables (at least six servings per week).
  • Other vegetables.
  • Berries, especially blueberries and strawberries.
  • Nuts.
  • Legumes (at least three servings per week).
  • Whole grains.
  • Extra virgin olive oil.
  • Fish.
  • Poultry.

It also recommends limiting:

  • Ultra-processed foods.
  • Sweets.
  • Fried foods.
  • Processed meats high in sugar, salt and unhealthy fats.

The goal isn't perfection.

It's building a sustainable dietary pattern that supports long-term health.

What About Ultra-Processed Foods?

The same study found that higher consumption of ultra-processed foods was associated with an increased risk of dementia, Parkinson's disease, depression and anxiety.

The authors suggest that part of this relationship may be explained by changes in metabolism, inflammation and biological ageing.

Again, these findings describe associations rather than proving direct causality.

Even so, the message is entirely consistent with the growing body of scientific evidence accumulated over recent years.

So... Does Brain Health Depend Only on What We Eat?

No.

And this is perhaps the most important message in the entire article.

Food doesn't act directly on the brain like flipping a switch.

Instead, it first changes the body's biological environment.

  • It improves metabolism.
  • It reduces low-grade inflammation.
  • It supports healthier biological ageing.
  • It helps maintain a healthier body composition.

It is this healthier internal environment that allows the brain to function more efficiently, reducing neuroinflammation and lowering the physiological burden associated with living in a chronically inflamed body.

Some observational studies have estimated that adherence to the MIND Diet may be associated with a 35–53% lower risk of developing Alzheimer's disease. However, these findings show an association rather than proving a cause-and-effect relationship.

More recently, clinical trials such as the MIND Trial have shown that following the MIND Diet for several years improves overall diet quality and may produce modest cognitive benefits. However, it has not yet conclusively demonstrated that it prevents dementia. Research is ongoing.

The Role of Nutritional Supplements

Nutritional supplements cannot replace a lifestyle that regularly provides moments of calm and recovery.

However, they may offer valuable support during periods of prolonged stress or when maintaining healthy habits becomes so difficult that those habits themselves create additional stress.

Supplements do not eliminate stress, but certain ingredients may support sleep quality, brain function, inflammatory balance and the body's ability to adapt to stress.

Level of Scientific Evidence

  • ⭐⭐⭐⭐⭐ High evidence.
  • ⭐⭐⭐⭐ Moderate evidence.
  • ⭐⭐⭐ Promising evidence.
  • ⭐⭐ Limited evidence.

1. Magnesium

⭐⭐⭐⭐⭐ High Evidence

What Does the Evidence Say?

Magnesium is involved in more than 300 enzymatic reactions throughout the body, including many essential functions of the nervous and muscular systems.

Research suggests that supplementation is particularly beneficial when dietary intake is insufficient or deficiency exists, helping improve sleep quality, muscle tension and certain stress-related symptoms.

It should not be considered a universal relaxation supplement.

Who May Benefit?

  • People with a low intake of vegetables, nuts, seeds and legumes.
  • Athletes with high sweat losses.
  • People experiencing frequent muscle tension.
  • Individuals with non-restorative sleep linked to inadequate magnesium intake.

Recommended Forms

  • Magnesium bisglycinate.
  • Magnesium citrate.
  • Magnesium malate (particularly when fatigue is the main symptom).

Typical Daily Dose

200–400 mg of elemental magnesium per day.

2. Ashwagandha (Withania somnifera)

⭐⭐⭐⭐ Moderate Evidence

What Does the Evidence Say?

Ashwagandha is one of the most extensively studied adaptogenic plants.

Several clinical trials have shown that it may reduce the perception of stress while improving overall well-being and sleep quality.

Some studies have also reported moderate reductions in cortisol levels, although this is only one of its mechanisms of action.

Who May Benefit?

  • People experiencing chronic stress.
  • Individuals feeling physically and mentally overwhelmed.
  • People who struggle to unwind at the end of the day.

Typical Daily Dose

300–600 mg of a standardised extract per day.

Precautions

Not recommended during pregnancy.

People with hyperthyroidism or autoimmune diseases should only use it under the supervision of a healthcare professional.

3. Omega-3 (EPA + DHA)

⭐⭐⭐⭐ Moderate Evidence

What Does the Evidence Say?

Omega-3 fatty acids are not sedatives.

Their primary role is to support normal brain function while helping regulate inflammatory processes.

Several studies suggest that adequate omega-3 intake may support mood and improve resilience to stress, particularly in people who consume little oily fish.

Who May Benefit?

  • People who rarely eat oily fish.
  • Individuals with increased inflammatory burden.
  • People with high cognitive demands.
  • Athletes.

Typical Daily Dose

Between 1 and 2 g of EPA + DHA daily, preferably formulas with a higher EPA content when supporting mood is the primary goal.

Omega-3 + Schisandra (Pure Omega)

On one hand, omega-3 fatty acids contribute to normal brain function and help regulate the inflammatory response, a process that can become disrupted when stress persists over time.

On the other hand, Schisandra chinensis is an adaptogenic plant traditionally used in Eastern medicine. Current research suggests it may help the body adapt to both physical and mental stress, reducing fatigue while supporting cognitive performance. Although the evidence is promising, it is still less extensive than that available for other adaptogens such as ashwagandha.

The formula also provides vitamin D, an essential nutrient that supports normal immune system function and is commonly deficient in many populations.

Who May Benefit?

  • People experiencing prolonged physical or mental stress.
  • Individuals suffering from fatigue or exhaustion.
  • People with a low intake of oily fish.
  • Those looking to support brain function and inflammatory balance through a comprehensive approach.
  • Athletes and people with demanding intellectual workloads.

Why Could It Be Beneficial?

  • Supports normal brain function thanks to DHA.
  • Omega-3 fatty acids help regulate inflammatory processes.
  • Schisandra may enhance the body's ability to adapt to stress (adaptogenic effect).
  • May help reduce both physical and mental fatigue.
  • Provides vitamin D to support normal immune and muscle function.

NX Resolve® (Nutriygenix Lab)

When we think about inflammation, we usually think only about stopping it.

However, science has shown that resolving inflammation is not the same as suppressing it.

Our bodies naturally produce molecules called Specialised Pro-Resolving Mediators (SPMs), which are mainly derived from the omega-3 fatty acids EPA and DHA.

Their role is not to block inflammation but to help the body complete the inflammatory process properly by removing damaged cells, promoting tissue repair and restoring homeostasis.

When this resolution process is impaired, inflammation may become chronic and contribute to cardiovascular, metabolic, immune and even neurological disorders.

How Is This Related to Stress?

Chronic stress promotes low-grade inflammation and increases oxidative stress.

Although SPMs are not a treatment for stress itself, they may help improve the biological environment in which the nervous system functions by supporting the body's natural inflammatory resolution process.

This is an emerging area of research showing particularly promising results in inflammatory conditions and tissue recovery.

Who May Benefit?

  • People with chronic low-grade inflammation.
  • Individuals experiencing prolonged physical or mental stress.
  • Athletes undergoing intense training.
  • Anyone wishing to support the body's natural inflammation-resolution mechanisms as part of a comprehensive health strategy.

Why Could It Be Beneficial?

  • Supports the body's natural inflammation-resolution process.
  • Does not work like a conventional anti-inflammatory.
  • May support the body's natural tissue repair mechanisms.
  • Derived from bioactive compounds obtained from EPA and DHA.

4. Lavender (Silexan®)

⭐⭐⭐⭐ Moderate Evidence

What Does the Evidence Say?

Standardised oral lavender extract (Silexan®) is one of the plant-based supplements with the strongest evidence for mild anxiety and stress-related symptoms.

It may promote relaxation without causing dependence or significant sedation.

Who May Benefit?

  • People with mild anxiety.
  • Individuals experiencing persistent nervousness.
  • People with ongoing feelings of tension.

Typical Daily Dose

80 mg of standardised extract daily.

5. Melatonin

⭐⭐⭐⭐ Moderate Evidence

What Does the Evidence Say?

Melatonin is a hormone involved in regulating the circadian rhythm.

There is strong scientific evidence supporting its use for improving sleep onset in situations such as jet lag, delayed sleep phase syndrome and certain forms of insomnia.

It should not be considered a treatment for stress itself.

Who May Benefit?

  • People who struggle to fall asleep.
  • Shift workers.
  • Travellers experiencing jet lag.

6. L-Theanine

⭐⭐⭐ Promising Evidence

What Does the Evidence Say?

L-theanine is a naturally occurring amino acid found in green tea.

Research suggests it may promote a state of calm while maintaining attention and cognitive performance, without causing significant drowsiness.

Who May Benefit?

  • People experiencing work-related stress.
  • Students.
  • Individuals who struggle to concentrate under pressure.

7. Saffron

⭐⭐⭐ Promising Evidence

What Does the Evidence Say?

Standardised saffron extracts have shown promising results in improving mild symptoms of anxiety and low mood.

Although the scientific evidence continues to grow, saffron should not replace medical treatment when this is required.

Who May Benefit?

  • People experiencing low mood.
  • Individuals with mild emotional stress.

8. Glycine

⭐⭐⭐ Promising Evidence

What Does the Evidence Say?

Glycine is an amino acid involved in numerous physiological processes.

Supplementation may help improve sleep onset and enhance the feeling of waking up refreshed in some individuals.

Who May Benefit?

  • People whose main concern is poor sleep.
  • Individuals with non-restorative sleep.

9. Psychobiotics

⭐⭐⭐ Promising Evidence

What Does the Evidence Say?

Certain probiotic strains appear to influence the gut-brain axis through mechanisms involving the immune system, metabolism and specific neurotransmitters.

Not all probiotics produce these effects, and research in this area is still evolving.

The strains with the strongest evidence include:

  • Lacticaseibacillus paracasei LA903 and Lacticaseibacillus casei LA205.
  • Bifidobacterium longum and Bifidobacterium infantis.
  • Lactobacillus helveticus.
  • Lactobacillus plantarum and Lactobacillus brevis.

Benefits are generally observed after approximately six weeks of supplementation.

Who May Benefit?

  • People with digestive symptoms linked to stress.
  • Individuals with gut microbiota imbalances.
  • People diagnosed with irritable bowel syndrome (IBS).

Alongside supplementation, naturally fermented foods such as sauerkraut, kimchi, kefir and dark chocolate (minimum 80% cocoa) may also help increase microbiota diversity.

10. Rhodiola rosea

⭐⭐⭐⭐ Moderate Evidence

What Does the Evidence Say?

Rhodiola rosea is an adaptogenic plant traditionally used in Eastern Europe and Asia to improve the body's ability to adapt to both physical and mental stress.

Clinical trials suggest that it may help reduce stress-related fatigue, improve cognitive performance during periods of high mental demand and increase feelings of energy and well-being, particularly in people experiencing exhaustion.

Its effects appear to be more pronounced on fatigue and mental performance than on anxiety itself.

Who May Benefit?

  • People experiencing physical or mental fatigue.
  • Individuals with highly demanding workloads.
  • Students during periods of intensive study.
  • Professionals experiencing exhaustion without clinical depression.
  • Athletes undertaking intensive training programmes.

When Should Rhodiola Be Chosen Instead of Ashwagandha?

Rhodiola rosea is generally the better choice when the main symptoms are:

  • Physical fatigue.
  • Mental exhaustion.
  • Reduced cognitive performance.
  • Lack of energy.

Ashwagandha is usually more appropriate when the main symptoms are:

  • Anxiety.
  • Difficulty switching off.
  • Emotional stress.
  • Sleep disturbances.

Typical Daily Dose

200–400 mg of a standardised extract per day.

It is generally recommended to take it in the morning or around midday.

Precautions

Although generally well tolerated, Rhodiola should be used with caution in people with bipolar disorder or those taking certain psychiatric medications.

Practical Summary

If the main issue is... Most Suitable Supplement
Stress accompanied by anxiety Ashwagandha
Physical and mental fatigue Rhodiola rosea
Low-grade inflammation SPMs (NX Resolve®)
Nervous system imbalance with digestive symptoms Psychobiotics
Low oily fish intake together with inflammation Omega-3 + Schisandra Complex
Mild anxiety Lavender (Silexan®)
Difficulty falling asleep Melatonin
Muscle tension or inadequate dietary magnesium intake Magnesium

If You Remember Just One Thing...

For many years, stress was considered purely a psychological problem.

Today we know that it is also an immunological, metabolic and biological process.

The goal is not to eliminate stress — that would be impossible.

The real goal is to help the body recover its ability to return to repair mode.

In other words:

You don't need to live without stress.

You need your body to remember how to recover from it.

Good health is not about never activating your internal alarm system.

It's about being able to activate it when necessary...

...and switch it off once the danger has passed.

Perhaps that's one of the best definitions of a healthy body.

Not a body that never experiences stress.

But a body that always retains the ability to return to balance.