Stress and Neurodegeneration: A Link You Cannot Ignore
We live in an incredibly stressful world, where stress has become a universal experience. Sometimes, it can feel like there’s no escape from the constant pressure of modern life. Imagine a typical day: you’re jolted awake by your alarm clock, rush through breakfast, and then get stuck in traffic on your way to work, already running late for that important meeting. Or perhaps you are attempting to get the kids ready for school while watching the news. The cycle of stress seems never-ending, and it can weigh heavily on your mind and body.
What if I told you that this relentless stress isn’t just making you anxious — it could be toxic to your brain?
Today, we are exploring an important and timely topic: the connection between chronic stress and neurodegeneration, with conditions like dementia and Alzheimer’s disease.
You have likely heard about well-known strategies for Alzheimer’s prevention, such as eating a balanced diet, regular exercise, avoiding toxins, getting a good night's sleep, and managing conditions like type 2 diabetes. But did you know that managing stress is another powerful tool in protecting your brain?
Chronic stress could be one of the hidden factors increasing the risk of Alzheimer’s, and we must explore this connection further. Let’s break down how stress affects your brain and body, why it’s problematic, and most importantly, how to reduce it for better brain health.
What is Chronic Stress and Why Is It Harmful?
Stress, in itself, is not the enemy. It is an evolutionary response designed to help us survive immediate threats. Thousands of years ago, our ancestors experienced stress as a reaction to life-threatening situations, such as running from predators. This short-term stress would flood the body with adrenaline and cortisol to provide the energy needed for survival — the fight-or-flight response.
However, the stress we face today is rarely life-threatening. It is often chronic — driven by work pressures, financial concerns, family obligations, and as a result of a constantly connected world. Chronic stress keeps the body’s fight-or-flight response activated for long periods, which is unnatural and harmful.
The problem with chronic stress is that it can lead to numerous health issues, many of which are related to brain function. While our ancestors’ stress was temporary, the stress we face today is constant, creating what is known as "micro-stresses" from everyday activities like multitasking or managing an overwhelming workload. Over time, these stresses accumulate, deeply impacting the body and the brain, lowering our resilience and damaging our DNA.
Four Ways Stress Harms Brain Health
Let’s explore the four primary mechanisms by which chronic stress increases the risk of Alzheimer’s disease:
Stress Alters the Gut Microbiome
The gut microbiome is key to overall health, including brain health. When under stress, the balance of gut bacteria shifts, altering their behaviour and gene expression. These changes impact how we metabolise food, feel after eating, and even regulate our mood.Studies show that stress hormones like norepinephrine can directly affect the gut microbiota, which can, in turn, produce substances that negatively influence both gut and brain function. Furthermore, bacterial metabolites can irritate and inflame the gut wall and increase intestinal permeability, a key factor in brain inflammation.
Maintaining a healthy, balanced microbiome is essential in protecting your brain from the risks associated with chronic stress.
Stress Disrupts Hormone Balance
Chronic stress leads to persistently elevated cortisol levels, a stress hormone. In small doses, cortisol helps you respond to acute stress, but when levels remain elevated for too long, it becomes toxic — especially to the brain.Excessive cortisol levels in the bloodstream lead to blood sugar dysfunction, insulin resistance and blood lipid imbalances. Considering that Alzheimer’s disease is considered type 3 diabetes, it makes sense to address the causes of stress and manage blood sugar levels.
Research shows that high levels of cortisol damage the hippocampus, a critical brain region responsible for memory. Over time, this damage can become irreversible, impairing cognitive function. At the same time, the amygdala, the fear centre of the brain based on past experiences, grows bigger and more dominant, leading to disproportionate stress levels, anxiety disorders, depression and social disconnection.
Stress Increases Inflammation
Chronic stress is a major driver of inflammation, which is a known contributor to a variety of health problems, including Alzheimer’s. Stress-induced inflammation causes oxidative damage to brain cells, similar to when we consume unhealthy foods or live a sedentary lifestyle.Prolonged inflammation can disrupt neurotransmitter balance and impair the brain’s ability to function optimally. In the long run, it can cause chronic inflammation, a leading factor of neurodegeneration.
Stress Raises Blood Sugar Levels
Elevated cortisol doesn’t just affect hormones and inflammation — it also raises blood sugar levels. When there is no danger to run from, like overwhelming work demands or money problems, the excess blood sugar has nowhere to go, leading to insulin resistance and increasing the risk of type 2 diabetes — a condition closely linked to Alzheimer’s disease.
“Stress-induced inflammation causes oxidative damage to brain cells, similar to when we consume unhealthy foods or live a sedentary lifestyle.”
As we continue to explore the factors that contribute to Alzheimer's disease, we must give special attention to chronic stress.
While other important prevention strategies like diet, exercise, avoiding toxins, and optimising sleep should be considered, we cannot ignore the long-term impact of stress on neurodegeneration.
The Evolutionary Shift: From Acute to Chronic Stress
Stress was originally a survival mechanism. Our ancestors faced acute stressors like wild animals or environmental dangers, and the body’s stress response helped them act quickly to stay alive. But in today’s world, stress is rarely about life-threatening danger. Instead, it’s chronic.
The Hidden Stressors: Multitasking and “Micro-Stresses”
A key culprit of modern stress is multitasking. Many of us pride ourselves on being able to juggle multiple tasks at once, but the truth is, our brains aren’t designed for it. Instead of being efficient, multitasking leads to “micro-stresses”— small, continuous stressors accumulating over time, creating a significant emotional and chemical toll on the brain.
Multitasking also creates a constant sense of urgency, keeping the stress response system active. Over five or ten years, this can manifest in serious health conditions like immune disorders, cancer, and neurological decline. If we want to protect our brains, one of the first steps is to stop multitasking, create clear boundaries in our daily lives and prioritise what is most important. This includes our health and mental well-being.
“Multitasking also creates a constant sense of urgency, keeping the stress response system active. Over five or ten years, this can manifest in serious health conditions like immune disorders, cancer, and neurological decline.”
Oxytocin: The Anti-Stress Hormone
While cortisol wreaks havoc on the brain, oxytocin — the “love hormone” — plays a protective role. Oxytocin is released when we touch (like a mother and her child), and experience connection, love, and relaxation. It directly counteracts the harmful effects of cortisol by promoting feelings of calm and reducing stress.
Engaging in activities that promote higher oxytocin levels, such as spending time with loved ones, practising gratitude, or even engaging in physical touch (hugging and being intimate with a partner), can be a powerful way to lower cortisol levels and protect brain health. As oxytocin levels rise, cortisol levels decrease, creating a hormonal balance that promotes overall well-being.
Melatonin: A Powerful Antioxidant Hormone
Melatonin is widely known as the “sleep hormone,” but its role goes far beyond regulating sleep-wake cycles. It is also a powerful antioxidant, protecting the body from oxidative stress during sleep.
Melatonin helps combat free radicals, supports immune function, and promotes overall cellular health. Its relationship with stress and cortisol is one of the key aspects that makes melatonin particularly useful in combating chronic stress and elevated cortisol levels.
Cortisol follows a natural daily rhythm. Under normal circumstances, cortisol levels are highest in the morning to help you wake up and gradually decrease throughout the day, reaching their lowest levels at night. This natural decline in cortisol allows the body to prepare for sleep, and melatonin secretion increases as darkness sets in.
However, chronic stress keeps cortisol levels elevated throughout the day, disrupting this natural rhythm and sleep. This is known as being “wired and tired” —you feel mentally and physically exhausted but unable to fall asleep because your body is still producing too much cortisol at the wrong time. This intrinsically prevents melatonin production, so you don’t feel sleepy and miss out on its antioxidant properties.
Indeed, when cortisol levels remain high as the sun sets, it inhibits melatonin production. This is problematic because melatonin is essential for sleep and acts as a powerful antioxidant, protecting the brain and body from the damaging effects of chronic stress.
With elevated cortisol levels, the body enters a state of hypervigilance, making it difficult to wind down. You may feel restless, unable to relax, struggle to sleep or stay asleep. Lower melatonin levels disrupt sleep and impair your body’s ability to repair and detoxify during the night, leading to a vicious cycle of poor sleep, heightened stress, and even more cortisol production the next day.
Melatonin’s ability to counteract the effects of elevated cortisol makes it a valuable tool in managing chronic stress. Here’s how:
Restoring Sleep Patterns:
While supplementing with melatonin is not recommended in the UK, the option is to promote natural production through good sleep hygiene (such as reducing exposure to blue light before bed). This helps lower nighttime cortisol levels, making it easier to fall asleep and promoting deeper, more restorative sleep.
Avoiding caffeine in the afternoon and eating earlier in the evening can also help reduce cortisol levels and increase melatonin production. Beware of artificial light exposure, like LED lighting, which inhibits the release of melatonin by unnaturally making your brain believe it is still daylight.
Reducing Oxidative Stress:
Chronic stress and elevated cortisol levels contribute to oxidative stress in the body. Melatonin acts as a potent antioxidant, helping to neutralise harmful free radicals and protect the brain and body from damage.
Promoting Relaxation:
Melatonin has calming effects, reducing the body’s heightened stress response and promoting relaxation. This improves sleep quality and can help reduce anxiety and the overall burden of stress.
Managing Stress for Better Brain Health
Reducing and managing stress is essential to protect your brain from neuroinflammation and neurodegeneration.
Here are some key strategies:
Practice Mindfulness and Meditation
Studies show that mindfulness-based stress reduction can help restore brain and gut microbiome balance.Meditation and cognitive behavioural therapy (CBT) have also been shown to improve brain connectivity, reduce stress, and promote a healthier gut environment by finding healthier ways to respond to stressors and increase resilience.
Focus on Single Tasks
Stop multitasking, as it only increases stress. Focus on completing one task at a time, and create clear boundaries between work, rest, and recreation to reduce cognitive overload.Do not take work to bed. Your brain may register the bedroom as a source of stress, deeply disturbing your sleep.
Nurture Relationships and Increase Oxytocin
Engage in activities encouraging meaningful connection and joy — like spending time with loved ones, hugging, or even playing with a pet. This can promote oxytocin and lower stress levels.Exercise and Eat Well
Physical activity and a balanced diet reduce stress, help balance hormones and reduce inflammation, all while supporting brain health.
Chronic stress is not just an emotional burden — it is a physiological threat to the brain that can significantly increase the risk of neurodegeneration and Alzheimer's disease. Addressing the root causes of stress and incorporating strategies to manage it effectively can help protect your brain and improve your overall health.
Reducing stress is not just about feeling better in the moment; it is about safeguarding your cognitive future.
Remember that you lead by example. You pass on your resilience (healthy coping mechanisms) to your children. The opposite is also valid. This may explain why anxiety disorders and depression can be transgenerational.