Mental and physical health are inextricably linked

In the UK, gyms and leisure facilities have been closed for a long period during the past year, leaving many people without their usual exercise space. Although autumn has turned the greens of our surrounding nature into bright yellows, oranges, and browns, the term “green exercise” still refers to any physical activities taking place outside in the nature.

In their study “What is the Best Dose of Nature and Green Exercise for Improving Mental Health? A Multi-Study Analysis”,¹  Dr Jo Barton and Dr Jules Pretty found that green exercise has positive impact on our mood and self-esteem. Although these are generally thought of as aspects of our mental health, evidence shows that our mood, emotions, and mental state have a direct link to our physical health. Psychoneuroimmunology (PNI) is the study of the interaction between our Central Nervous System (CNS), endocrine system, and the immune system.²

Over the past few decades, studies in PNI have found that our immune system and mental health are inextricably linked. It has been found that people with autoimmune diseases are more susceptible to depression and anxiety, and vice versa – people suffering from mental illnesses can have a suppressed immune system.^3,4

Negative stressors affect our immune system by the dysregulation of the hypothalamic-pituitary-adrenal axis and/or the sympathetic-adrenal-medullary axis.^2,5,6   These two pathways provoke the release of pituitary and adrenal hormones, for example adrenaline, noradrenaline, and cortisol, which can induce changes in immune function. This can make us more susceptible to infectious diseases, influence their severity, diminish the response of immune responses to vaccines, and slow wound healing.^2,6,7,8,9   Long term psychological stress can lead to alterations in immunoregulatory networks, causing increased risk for allergic and autoimmune diseases.⁵

Although studies looking into the effect of positive emotions on our immune system are scarce, a relationship has been found between positive affect and better immune functioning.^9,10,11   Pleasant emotions have been found to induce an increase in secretory immunoglobulin A and a decrease in salivary cortisol.^9,11,12   Positive emotional style has also been linked with greater resistance against a common cold.¹³  

Although we now know that our feelings, emotions, and outlook on life have a direct impact on our immune system and thereby physical health, it is not always easy to just be more positive. Life as we know it has drastically changed over the past year, bringing along worries about health, employment, and education to many homes across the world. Sometimes we cannot seem to shift from worrying to thinking positively. Luckily, there are plenty of resources and suggestions to aid us in this endeavour. Here are three that I have found extremely helpful and simple:

• Be physically active^14,15,16 -Whether it’s taking part in an online fitness class, like Essex Sport’s Facebook Live classes, or something less structured, such as going out for a walk or playing with your kids, regular physical activity has been proven to release stress-relieving and mood-boosting hormones and improve our sleep time and quality.

• Write down some positive thoughts every day^17,18  - This will help us make positive thinking a daily habit and provide us with a journal full of our personal positive experiences to look back to on days we might be feeling a bit down. The positive journal could include some or all these points:

  Today I am grateful for…

  My happiest memory from this week/month/year

  What has made me laugh recently?

  What went well today?
  
  

• Connect with people^19,20,21 - Humans are social beings. Although this year has made connecting with our close ones somewhat challenging, we are lucky to live in a world of technology, which provides us with so many options to stay in touch with friends, family, and acquaintances over long distances.  Being connected to others will increase our happiness, improve our physical health, and help us live a longer life.

It is now more important than ever to look after our mental and physical health. This will increase our mental resilience and decrease our visits to doctors in these challenging times. Luckily, our mental and physical health are inextricably linked and one will affect the other. By keeping physically active we are greatly benefitting our overall health and mood.