Are Chronic Illnesses Nature or Nurture and What Can I do to Help Myself?
Jan Rothney 
The blog explores the impact of nurture on nature and how to improve your own wellbeing, health and recovery.
Nature vs. Nurture: Making Sense of Chronic Illness in Long COVID and CFS/ME
For decades, people have asked: are our health outcomes determined by nature (our biology and genetics), or by nurture (our environment and experiences)?
Have you ever wondered why some people develop cancer or heart disease whilst others develop autoimmune and gut conditions or skin conditions? I have been fascinated for years, why under chronic stressful conditions and overload my body reacted by breaking out in skin disorders, gut problems and susceptibility to getting colds then completely shut down with M.E/CFS. Others around me would get high blood pressure, have strokes or develop anxiety/ depression. Well the likelihood,according to current research, is that we start with a predisposition (a weak spot) and this is only expressed when environmental conditions and lifestyle are stressful and unfavourable.
For conditions like Long COVID and Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME), the debate affects how society understands these illnesses, how doctors treat them, and how patients find validation. The truth, as the science now shows, is that it’s not one or the other—chronic conditions are affected by nature and nurture.
In a large English cohort (over 1.5 million cases), Long COVID risk factors included being female, of non-white ethnicity, obesity, and pre-existing conditions like anxiety, depression, or type II diabetes PubMed.
Vaccination clearly lowers the risk: in the ISGlobal study, only 15% of vaccinated individuals developed Long COVID, versus 46% of unvaccinated—highlighting how medical interventions interplay with environment and exposure News-MedicalHealio.
Knowing there may be a predisposition can be really useful because it means we are determined to do whatever we can to mitigate the circumstances under which the weak spot appears. If we know that people in our family have had heart disease, we will do whatever we need to do to help ourselves reduce the risk.
LIfestyle Matters
The Royal College of General Practitioners recognise that 70% of all their patients have chronic conditions that cannot be helped with medication alone; these include people with diabetes, autoimmune conditions affecting the skin, gut, heart disease, certain cancers, joints, autonomic nervous system and other conditions. They have developed training for all GPs and doctors called “Lifestyle Medicine” which targets the chronic condition from a nurture perspective. They focus on the 6 environmental pillars of “recovery”:
1.whole-food, plant-predominant nutrition
2. physical activity;
3.restorative sleep;
4.stress management;
5.avoidance of risky substances (like tobacco and excessive alcohol);
6. and positive social connections.
Whilst we may be more prone to developing certain illnesses, we now know that helping ourselves to live in the healthiest conditions can massively mitigate against developing the condition and alleviate symptoms- indeed people with diabetes 2 can reverse the condition through lifestyle, and experts are becoming aware of the incredible impact of lifestyle and environmental factors on wellbeing. There is now a plethora of research papers showing that fermented foods, diverse plant based diet, exercise, restorative sleep, healthy air, and reducing stress is instrumental in maintaining well being, as well as enabling people to recover and improve from chronic conditions. We can have an “exhausted immune system" which shows up in biological markers BUT 80% of our immune system is the good bacteria in our gut lining, protecting the body. When the good bacteria are depleted under stress, antibiotics, poor diet and lack of sleep then of course our immune system is weakened and this makes us susceptible to colds, viruses, and gut problems.
Thankfully, we can build our own immune system by eating the foods that produce good bacteria, taking probiotics and Vitamin D3 with K2. This is such a cause for celebration for those who are keen to find nurturing ways to make their bodies more robust and recover from conditions affecting the gut and immune system.
For further reading have a look at Tim Spector’s “ Food for Life” and Megan Rossi”s book “ Eat Yourself Healthy ".Tim is a British epidemiologist, medical doctor, and science writer, working on the relationship between nutrition, the gut microbiome, and health. Megan is a dietitian, nutritionist and author specialising in the microbiome. Julie Bradbury”s book “ Walk Yourself healthy” was written after she was diagnosed with cancer and discusses how she believes her lifestyle contributed to her body falling apart and developing cancer. It not only advocates walking as exercise but all the other pillars included in “Lifestyle Medicine”.
So the focus for people shouldn’t be on proving it is genetic or proving it is environmental stressors and poor lifestyle balance; we have to work with what we have been given biologically and mitigate against the genes being expressed.
If I know I have an easily activated autonomic nervous system (which I have) then I can do the work on the Reset to Thrive programme and in my book ‘Breaking Free’ to reset the system and develop the human social defence skills needed to build resilience and recalibrate the system. If I know my weak spot under chronic stress is the immune system, I will (and now do) ensure I eat the bacteria friendly foods, take probiotics and supplements needed to maintain a healthy gut and immune system. Furthermore, learning to regulate the ANS means we improve the immune system and our ability to heal. Science shows that the autonomic system, the gut/ immune system and the brain are forever communicating with one another, and so how we think/ see life and how our gut health is, impacts on the whole body. Nurture matters.
Our genes are Not Fixed.
It is fascinating how much people need to find a biological reason for the illness; it means there is no feeling of blame, guilt, responsibility and effort but it also makes us powerless. If you believe your condition is “genetic" then you also probably believe you can do nothing about it because your understanding is that DNA is fixed.
However, whilst about 4% of health conditions are congenital, the majority can be modified. As Bruce Lipton, a cellular biologist explains in "Biology of Belief”, our genes provide the blueprint but they are controlled by signals from the environment — and importantly, by the environment created inside our bodies through our perceptions, thoughts, emotions, and beliefs.
Our genes switch on and off when they are instructed to produce certain proteins and chemicals, appropriate to the environmental conditions we are surrounded by or perceive ourselves to be in. This means stress chemicals, which create inflammation, are produced under conditions of stress whilst the growing and repair chemicals are produced under favourable conditions.
So much of the biological evidence shows a difference in biology when we are ill but this doesn’t mean the biology caused the illness; it is just as likely that the change in the biology is a result of the body malfunctioning. Only a longitudinal study, following a population from birth, can determine cause and effect and these studies are not feasible for the vast majority of research. Interestingly, identical twin studies, where people are born with identical DNA/genes and biology have been shown to vary in later life according to their environmental circumstances. Recently, Chris and Xand van Tulleken, identical twin doctors, produced a podcast on how to help yourself become more healthy. Xand was 30lb heavier than Chris and the difference couldn’t be genes; it turns out that he ate a highly processed food diet and did little exercise. Chris went onto write the fascinating book called “ Ultra Processed People” whilst Xand wrote “ How to Lose Weight Well” because even though they have predisposed genes, nurture determined how they ended up being in terms of health and well being.
Welcome Research and Use it to Help Yourself.
So when you look at research into genes and nature- please do not be disheartened, scared or feel powerless; we can influence whether our predisposition is expressed or not according to the six pillars of nurture: reducing our stress and perception of stressors, exercise, eat well, get restorative sleep, fresh air, nurturing social engagement and reduce physical stressors on the body such as smoking, drinking and ultra processed foods.
So what is the evidence for a predisposition, based on research that looks at people who already have the illness, not how they were before becoming ill? Here are a few interesting studies:
Nature: How Our Biology Shapes Chronic Illness
1. Genes Matter
The recent DecodeME study—the largest of its kind—recently identified eight genetic regions linked to CFS/ME. These genes are involved in immune and nervous system function, pointing to a strong biological basis. This means there may be a predisposition to developing chronic conditions associated with the immune system and the autonomic system which regulates digestion, heart and energy levels amongst other physiological. Were you the child whose autonomic nervous system was easily activated? Did loud noises, an unfriendly tone of voice or expression affect you physically? Even if we have an easily activated system, which increases inflammation and affects illness, we can learn to regulate it- ‘Breaking Free’ and ‘Reset to Thrive are designed to teach us how to regulate our overactivated ANS and calm the inflammatory response.
Research into Long COVID found a variant near the FOXP4 gene increases risk by about 60% which suggests there may be a predisposition. This has been confirmed across multiple international cohortshttps://doi.org/10.1038/s41588-025-02100-w
Numerous studies are also finding a dysregulation of inflammatory cytokines and “there is convincing evidence that in at least a subset of patients ME/CFS has an autoimmune etiology. Further efforts are required to delineate the role of autoantibodies in the onset and pathomechanisms of ME/CFS in order to better understand and properly treat this disease.” Currently, studies do not know if dysregulation is a cause or effect. Sotzny (2018).
Helping Ourselves to Improve Our Wellbeing and Recover Better from Chronic Conditions like CFS and Long Covid or Pain.
Learn to Reduce Stressors or Overload and Respond Differently to Stressors, including symptoms. In the Reset to Thrive programme and book ‘Breaking Free' we focus on the evidence that the dysregulation comes from an imbalance of the neurological biosocial system. This model is the one that is currently showing ways to enable people to recover and improve from chronic pain, chronic fatigue and other chronic illnesses. When we regulate our autonomic system, change the messages the brain is receiving and the alarm signals it is sending to the body by way of symptoms then we can reduce inflammation, become more robust dealing with life and we can develop lifestyle habits that enable us to be well and healthy again.
Our Reset to Thrive programme offers Nidra Yoga, free courses on breathing, somatic body work and cognitive reframing to help you live in the healthy vagal system and let the body heal itself.
Learn to feed the body and the soul with healthy bacteria friendly foods.
Exercise is so important. We show people how to be confident exerting the body again when it has been so affected by CFS or Long Covid because too often people are taught that exertion is causing their malaise which is not true.
Restorative sleep is essential; in the book and the Reset to Thrive programme we offer tips on getting restorative sleep which enables the body to heal and repair.
Decide that we all have a weak spot which does flair up under pressure and chronic overload or stress so commit to making your environment as healthy and favourable as possible. Nurture yourself and work with nature.
