• Is there a relationship between our mind and our body?
• Can our mental health influence our physical health – and vice versa?
• How can we increase the chances of having a healthy mind in a healthy body? 

“There is no real division between mind and body because of networks of communication that exist between the brain and neurological, endocrine and immune systems,” Oakley Ray, Professor Emeritus of Psychology, Psychiatry and Pharmacology at Vanderbilt University (Nashville, USA).  

The Power of the Mind? - We have probably all heard of the placebo effect. MedicineNet.com explains, ‘Expectation plays a potent role in the placebo effect. The more a person believes they are going to benefit from a treatment, the more likely it is that they will experience a benefit.'  

The Placebo Effect in action – The impact of the placebo effect on insomnia patients is a particularly interesting example. One study aimed to determine the size of the placebo effect for insomnia systems when comparing placebo treatment with no treatment. The analysis indicated that placebo treatment led to improved sleep patterns (including sleep time and quality) compared to patients that received no treatment. This demonstrates that the power the brain has in sending signals to the body when it had expected a powerful intervention to help it sleep. 

The Immune Brain Loop - Researchers now refer to the ‘Immune Brain Loop’ to describe the complex ways in which the brain sends signals to the body’s immune system and vice versa. The Psychoneuroimmunology Research Society is an international organization for researchers from a wide range of scientific and medical disciplines who are interested in interactions between the nervous system and the immune system, and the relationship between behaviour and health.

Can mental stress make us physically ill?  

Some evidence suggests that stress can result in an increased risk of illness, including:  

• The common cold (in Professor Sheldon Cohen’s research - apparently from a reduced ability to regulate inflammatory responses).
• Heart disease (in the view of the World Heart Federation)
• Diabetes (according to a 35 year study in Sweden)
• Autoimmune diseases, such as rheumatoid arthritis (as in this small study published in 2014).  

The impact of stress on our physical health is also evidenced through other studies, which also found that individuals that had experienced early-life adversity (stress at a young age) were more likely to experience physical and mental health problems in adulthood. 

Additionally, evidence suggests that mind-body therapies can help reduce stress. These include meditation and cognitive behavioural therapy.    

Might mental health affect our physical health?  

Mental illness appears to shorten physical life expectancy significantly for both men and women. For example a 10 year study of over 5,800 people in the US found that depression appeared to increase the risk of death from cardiovascular causes, like heart attack and stroke.  

One possible explanation is that depression may have had an evolutionary value. It seems to have provided short term help in fighting infection (a major source of death for thousands of years) through changes it triggered in the body. However, it has become counterproductive as people live longer and infection becomes less of a risk, and as the changes triggered in the body proved harmful over the longer term.     

The Mental Health Foundation notes that research demonstrates that people with a mental health problem are more likely to have a preventable physical health condition. This is due to factors such as genetics (some mental/physical health conditions are linked), low motivation which can impact energy or motivation, and lack of support to change unhealthy behaviour e.g. smoking, drinking.

A Healthy Mind in a Healthy Body? 

The relationship between mind and body is a two-way process. For example:  

• Overweight and obese individuals may be at greater risk of stress related diseases than those within a healthy weight range.
• Physical exercise appears to reduce the symptoms of depression - and may even reduce the risk of becoming depressed.
  
• People who are obese and have other physical symptoms of metabolic syndrome (like high blood pressure, an inability to control blood sugar levels and abnormal cholesterol levels) appear to experience a more rapid cognitive decline (i.e. a decline in the functioning of their mind) than people who are a normal weight.
  
• Eating a healthy Mediterranean diet (rich in vegetables, fruits, nuts, whole grain and fish) seems to slow the rate of cognitive decline as we age and reduces the risk of developing Alzheimer’s disease.
• Participation in outdoor nature-based activities (e.g. gardening, green exercise and nature-based therapy) can in some cases reduce anxiety and improve depressive mood.
  
• Education (exercising our mind) seems to have a number of physical health benefits
  
• So too does positive thinking and dispositional optimism.   

So, it seems that what we do to and with our body can affect what happens to our mind – and vice versa.  

Conclusions:  

• Our mind can influence our body (as with the placebo effect) – and vice versa.
• Stress, depression and mental illness all appear to increase the risk of physical illness – and if prolonged, may shorten life expectancy.
• Fortunately, there are sources of support to help (as in the right-hand column).
• What is good for our bodies appears to also be good for our brains. If we maintain a healthy weight, exercise and eat a healthy diet, we reduce the risk of depression, dementia and cognitive decline.
• Likewise, what is good for our brains also seems to be good for our bodies. Mind-related factors, such as positive thinking, dispositional optimism and nature-based interventions all having a beneficial impact on physical health.
• By following a healthy lifestyle (as explained in more detail on the Age Watch website) there are likely to be many benefits for both your body and your brain. 

Lindsey Stack, October 2022. Next review date, September 2026.