Clinical PNI – What is it and what can it do for you?


What’s in a name?
And why such a long word?

PNI_human_sThe clues are there. Psychoneuroimmunology (PNI) is the science that studies how psychological (thoughts and emotions) and neuro-endocrine influences (hormones and other chemical substances) affect the immune system (inflammation and protection against infection).  So PNI considers how your emotions and thoughts impact your brain, your hormones and ultimately your ability to protect yourself against disease. But why focus on the immune system?

In fact PNI encompasses more as it considers all the systems of the body  as interconnected in a logical and integrated unity.  The reason why the immune system is mentioned in the name is simple: the immune system is the only one capable of taking over the whole system. And the logic of that is simple: the immune system as our defence system should be able to take over when necessary (i.e. when threats are perceived). In extreme cases of unresolved threat or danger, as in severe burning or sepsis (but sometimes also through unresolved past trauma), the immune system will sap all the resources available in the body and eventually exhaust all the reserves. This is seen for example when people in intense care units lose weight and muscle mass in an uncontrolled manner, despite the hospital’s best efforts to keep them alive.  What ultimately kills the person is the triggered immune system in a state of acute activation. This is one of the extreme ends of a situation. The opposite side to that is when the immune system fails in its surveillance to protect us from either microbes (invaders) or malfunctioning cancerous cells (tumours), which can multiply uncontrollably and  grow powerful enough to kill us.   Nothing is more important than survival and that’s why the immune system has the final decision over resources.

So the immune system could be said to be the ultimate system.  In terms of energy demands, the brain is normally at the top of the hierarchy of organs. The brain consumes huge amounts of energy when compared proportionally to other parts of the body.  Once again, there is a logic to that: one of the reasons why humans have survived through evolution for so long and been able to thrive in so many different parts of the planet is due to the size and function of a hugely energy-expensive brain.  In evolutionary terms, it makes sense to prioritise the brain.  But even the brain will be taken over by the ‘defence system’ in a fight for survival.   That means when the immune system is active, the brain will suffer a decrease in available energy.  We all know that because when our immune systems are busy fighting a flu, we can hardly afford energy to think or move.  The brain and the rest of the body is deprived of energy and our behaviour changes in order to save energy.  We lose interest in activities, lose motivation for social interaction, we lose power from our muscles. We lie down and sleep in order to get well soon. This is a perfect illustration of the immune system taking over the body’s energy resources in its need to fight back infection.  But what about other situations in which the immune system is active but not able to resolve an infection or a state of chronic (ongoing) low-grade inflammation? How does that affect your energy levels, brain fogg and motivation? What about the connection between stress levels and chronic activation of the immune system (what we call ‘cold inflammation’)? There is substantial evidence that a state of chronic subclinical inflammation is involved in the aetiology of many common diseases from clinical depression to auto-immune conditions. Therefore, an understanding of how symptoms, pathology and physiology relate in a systemic approach with a focus on the immune system makes a lot of sense according to the scientific knowledge that has been accumulating over the past few decades. So from the name you can begin to see that PNI is a complex but also very logical approach to the understanding of how the body functions as an integrated system in health and disease.

How should we look at chronic diseases to truly understand how to deal with themt?

PNI is a relatively new science and its emergency comes from the crucial need to combine expert knowledge from different fields in one science that focuses on systemic influences and outcomes. A science that finally acknowledges that all the parts belong to the whole; a science that is based on the premise that all biological aspects of a person are interconnected and functioning together. PNI was born out of an effort to   ‘zoom out’ and look at the bigger picture in order to identify the correlations between different parts of the body (organs, mind and emotions) and the logic behind symptoms.  How many times do we get the impression that each of the experts is focusing deep on their own fields but completely ignoring the links that one part of the system has with another? Or more specifically, in healthcare terms, have you ever had the impression expert consultants try to resolve your symptoms in isolation, without really linking them together or considering your different problems might be related to the same systemic imbalance?  The niggling issue behind this tendency to focus on isolated symptoms lies in the perception that there must be a logic to your symptoms that goes beyond the singled out pathology of an organ.  Have you ever experienced a health problem being treated in an isolated and reductionist way which gives you the impression you are reduced to a set of symptoms,  which sometimes fit and other times don’t fit with your individual case?  If you were ever under the care of several healthcare professionals, consultants and doctors who seemed not to communicate with each other, you understand why PNI has emerged as a much needed new science.

Another powerful dimension to PNI is its foundation on evolutionary biology.  No matter how scientific biomedical sciences evolve to be, the normal functioning of the human biologic machinery will always need to be seen as an old product of slow evolutionary shaping. By ‘slow’ it should be understood that the process has been happening through millions of years and the human species that walks the Earth today has exactly the same genetic makeup of hundreds of thousands of years ago. With this idea in mind, it becomes much easier to perceive that sudden changes in the environment, such as the huge differences in food availability and composition observed in recent years, will affect human health from the outside. In other words, whilst our physiology has not changed for over 200.000 years, our environment and lifestyles have been completely transformed in as little as 200 years. What once was normal human food, normal human exercise and behaviour is now becoming a distant memory in the past. Whilst artificial environments, processed foods, chronic stress, lack of physical movement and effort have become part of our daily routines, our bodies remain the same ancient biological systems that were adapted to thrive in a natural setting characterised by food scarcity, huge physical demands, community bonds and intimate contact with nature.  The question posed by PNI is: what impact do all these outside changes bear on our health and behaviour? How well can we adapt to Modern living and what is the price to pay? At what point do abundant food, comfort, hygiene and protection become too much of a good thing?

Interestingly, what evolution has to show is that the body will sensibly sacrifice health in exchange for survival and that’s why chronic diseases exist.  With the help of evolutionary biology, it is possible to understand the logic of chronic degenerative conditions. A disease that doesn’t confer an advantage from a survival point of view is eliminated by natural selection. The escalating wave of chronic diseases taking over especially Modern Western societies these days seems to be no more than the best physiologic response our species has been able to find in order to cope with abrupt changes in the environment to remain alive (albeit ill). This firm background offered by evolutionary biology helps to give us perspective.  It serves as a ‘safety net’ and solid foundation to which we can always refer back in order to avoid getting caught up by our own anticipation to create new solutions out of context.

A new science based on old clues

Despite the complicated pronunciation, the long name ‘psychoneuroimmunology’ is more than justified. It really is as small a name as it could be because in fact even a long name like that doesn’t do justice to the complexity of the science.  Although it is so obvious that a human being is more than the collection of biological systems and physiological functions, it has taken us a long time to acknowledge the influences of the psyche, emotions and thoughts on health. Today, psychological and emotional aspects are recognised as important dimensions of mental health but how this realm relates to other parts of the body and disease states is not yet so clearly established.  To this day we still see body and mind as separate entities in healthcare models. Physical symptoms are no doubt different to psychological or mental-health related symptoms but the mistake lies in their separation as two unconnected domains.  There is no doubt, for example, that pain has an impact on your emotional state. That’s easy to grasp considering chronic or acute physical pain is not associated with happy feelings, motivation or positive emotions. Why then wouldn’t the reverse effect be acknowledged as significant as well? In the example of pain perception and associated emotions, isn’t it clear that emotional states can impact pain perception? If we recall the  times in our lives when the very fact of feeling positive, motivated, happy or excited has literally dampened our perception of pain it will be easy to see how the influences between the physical and emotional realms work both ways. What about hunger that disappears when you first fall in love? One can exist on almost thin air when first taken by the powerful feelings of falling in love.  Has anyone ever wondered why an emotional state would interfere with something as basic as the need to eat? After all feeding and energy production is the most primitive physiological need that affects pretty much every cell and system in the body. Would it be right to say that your physiology is altered by your emotional state?  What about specific functions in the body, for example, the ability to reproduce or fight infection, how are they affected by the chemistry of emotions and stress? Do different types of emotion and psychological states have different effects on  diseases? What is the biochemistry of these very clear effects we all know to exist but haven’t yet had a chance to understand? The need to answer these and many other questions is what’s at the core of PNI.

I think the importance to connect body and mind is undeniable nowadays and many missing clues for the real solutions to many physical symptoms may be where we have neglected to look.  However, PNI is not a theoretical hypothesis, a philosophy or a ‘ feel good mind-soul therapy’.  PNI is neither simplistic nor reductionist.  It is scientific, complex and evidence-based.  In PNI you won’t be told ‘it is a matter of your state of mind’ nor is the solution a simple ‘think positive and everything will be OK’.  Although this might be helpful, PNI is not about subjective interpretation and opinions about the ‘unknown’.  PNI is based on hard-science that is out there right now, flourishing in many different specialist fields such as biochemistry, physiology, neuro-endocrinology, epigenetics and evolutionary biology.  The unique feature of PNI is it is the first science to bring these several areas together in a combined approach to therapeutic uses with many applications in states of chronic disease. In clinical PNI, therapists are trained to understand the physiology of disease and relate it to the  evolutionary rationale that has shaped the biochemical mechanisms that justify the development of pathology.  From intra-uterine and early epigenetic programming to cognitive development and life experiences, the biological reasoning of an individual as a whole person is analysed with a view to understand the manifestation of physical symptoms and chronic diseases.  Therapeutic measures and recommendations are based on nutritional science, exercise and lifestyle modifications as well as neuro-linguistic programming and reframing techniques to help individuals see the links and connect the pieces of the puzzle to address imbalances of physiological and emotional nature.

What else plays a part?

Another fact that has taken long to gain respect within the medical understanding of health and disease is the influence of stress on the many systems of the body. Today it is not so difficult to make a point that your stress levels impact not only on how you behave and feel but also on your long term health status. The chemistry of the stress hormones in a nutshell can be summarised in one main point: redistribution of resources according to priorities. There is only so much energy available for immediate use in the body and all organs and systems have to make do with that.  I guess you might think we can always eat more if we need more energy but in pathological states where the immune system is active, it won’t quite work that way.  In fact, eating behaviour and digestion are examples of functions that can get dampened down by a busy immune system.  For example, how was your appetite last time you had a fever? Was eating a priority then? You can see that if things were that simple, we wouldn’t be on this growing wave of ever increasing chronic diseases right when food has become easily available with the advent of fridges and supermarkets.  Obesity would be an advantage if we could access our energetic reserves in that way. In fact, the very nations plagued with chronic diseases such as diabetes, cancer, obesity and auto-immunity are the ones where access to food is easy and abundant.  Is there a logic in that? You bet there is and those are the kinds of connections PNI focuses on. The links between lifestyle and health status, physical exercise, diet and disease are evident and the biochemistry behind them is revealing crucial information to the correction of physiological states of imbalances.

So how can PNI help in practical terms?

PNI is an exciting science and a much needed one. Specialist knowledge has never been so prolific and accessible. It makes complete sense to combine different expertise for greater results. And that is precisely the reason why I jumped on the opportunity to study clinical PNI. This is something so new that it is hard to find it but it is flourishing in Germany, Netherlands, Spain and other parts of Europe. Clinical PNI at post-graduate level is taught to healthcare professionals who have an understanding of physiology and biochemistry plus clinical experience in supporting sufferers of chronic diseases.  But PNI is for those who are willing to think outside the box.  Links and connections are made outside the box. There is no other way to see the connections if you don’t look out for them.  So it is a very complex study that will take experts out of their comfort zones.  But as one of my teachers said once: ‘you can only learn something new out of your comfort zone!’ My expertise is in nutrition and I enjoy the biochemistry of food but I want to be more than an expert looking at food to help clients.  I want to look at my clients and see how my expertise can help them achieve what they want. There is a big difference there. I hope you can see it.


  1. I am a nurse at a big magnet hospital. I see illness at its worst every shift I work.
    I am a strong believer in the body and cellular function. I see the need for a transformation in the education, resource and management of body, mind, spirit and cellular connection in the world we live in now.

    1. Hi Bree,
      Thank you for your comment. It is wonderful to see healthcare professionals aware of the importance of a systems approach and willing to work together in order to achieve better results for their patients. That’s the future of effective healthcare for long term wellbeing.
      Best wishes,

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