17 June 2021
This article was guest written for Ending Loneliness Together by Associate Professor Elisabeth Lambert, Faculty of Health, Arts & Design at Swinburne University of Technology.
I am a researcher at the Iverson Health Innovation Research Institute at Swinburne University of Technology. I specialise in understanding the mechanisms responsible for the development of cardiovascular and cardiometabolic diseases. Specifically, my work focuses on explaining the physiological pathways to diseases in order to develop strategies to prevent, slow down and reverse the progression of disease development.
We now know that loneliness is negatively associated with multiple health outcomes
A large body of work has focussed on psycho-social determinants of disease. For many years we have known that being single or living alone can be associated with certain diseases – of course just because somebody is single or living alone does not necessarily mean that they are lonely. Nevertheless, lonely individuals tend to report poorer quality of life compared to those who do not feel lonely. It seems that the feeling of loneliness impacts on an individual’s general wellbeing, for example, lonelier individuals often report that they sleep poorly or have more trouble to concentrate. We now know that loneliness is negatively associated with multiple health outcomes, in particular depression and anxiety are often present in lonely individuals and physical health is poorer.
These observations are significant because it is estimated that loneliness increases earlier death by 26%. The reasons for earlier death are uncertain but some studies conducted in Denmark and England suggest that lonelier people are at higher risk of developing cardiovascular disease and type 2 diabetes in particular. There is however little evidence to indicate a relationship between loneliness and incidence of cancer.
There are already many factors that are known to influence our cardiovascular and metabolic health. For example, our genetics, our diet, whether we exercise, how well we sleep, our mental health and socio-economic status are all important. The fact that feeling lonely can also factor into our cardiovascular health is significant and suggests that loneliness may influence factors that contribute and accelerate the disease process. Early signs of disease may include elevated blood pressure, elevated blood glucose concentration, lipid abnormalities or excess weight. All of these factors can be influenced by the sympathetic nervous system, our so called “fight or flight” system.
The mechanisms involved are unclear, yet most likely result from a combination of psychological, biological and behavioural mechanisms. It is important to appreciate that these three components are interrelated and when one factor is influenced or affected, it likely affects another. The complex interrelationship of these systems is what likely links loneliness to an increased risk of cardiovascular disease.
Some psychological mechanisms that could explain the link between loneliness and cardiovascular diseases may include stress, negative mood and depression. People who are suffering from depression or anxiety are twice as likely as the general population to develop cardiovascular diseases. We know that these conditions impact the endocrine, the immune systems and the autonomic nervous system, which, together, ultimately control our general health. Poor regulation of these mechanisms may in the longer-term lead to the development of cardiovascular and metabolic diseases and increased risk for premature mortality and disease.
For example, disturbances of the sympathetic nervous system (responsible for the “fight or flight” response) may play a role in leading to poor cardiovascular and cardiometabolic health. Activation of the sympathetic nervous system is linked to the development and maintenance of hypertension. It may also impact on vascular function as well as influence the heart and kidney functions and immune system, even in people with no (obvious) pre-existing cardiovascular disease.
Feeling lonely may impair the capacity of an individual to self-regulate and avoid negative behaviours leading to excessive alcohol intake, poor diet, sedentary behaviour and smoking
The central nervous system changes that occur as a result of loneliness may activate the hypothalamic-pituitary-adrenal axis which is known to increase circulating levels of cortisol and pro-inflammatory markers that can result in an array of adverse health outcomes, including accumulation of fat, changes in blood pressure and glucose regulation but also altered brain functioning, impaired cognition, and neurodegeneration.
Finally, feeling lonely may impair the capacity of an individual to self-regulate and avoid negative behaviours leading to excessive alcohol intake, poor diet, sedentary behaviour and smoking.
While the association between loneliness and adverse health outcomes has been well researched, there is limited data to indicate how loneliness increases the risk of developing cardiovascular and metabolic diseases – the physiological mechanisms linking loneliness with poor health outcomes are not known. In addition, most of the studies to date have been performed in older individuals and in those with pre-existing cardiovascular diseases.
However, we know that young people, in particular those between 18 and 29 years, report the highest prevalence of loneliness out of all age groups. Focusing on young adults before the onset of chronic disease is crucial to identify the mechanisms implicated in the acceleration towards chronic disease. Markers of disease can be detected early in life but the impact of loneliness on young people’s cardiometabolic health has never been examined. Identifying the commonly accepted mechanisms that underlie the relationship between loneliness and cardiometabolic health is fundamental to our knowledge of how to prevent the incidence of cardiometabolic diseases in later adulthood. We also need to identify modifiable risk factors to consider how we can slow the progression to cardiometabolic disease.
Many patients do not think of loneliness as a health issue to be discussed with their physicians
Currently, loneliness is not systematically assessed or treated by clinicians; however, due to its potential adverse effects on health outcomes, the assessment and treatment of loneliness could be integrated into routine clinical care. The drawbacks here though are that loneliness is a subjective and emotional experience, assessment tools in clinical practice remain problematic and appropriate and effective treatment paradigms are still to be developed and tested.
From a public health perspective, the adequate training of health care providers to perceive, detect, and respond to loneliness among patients should be encouraged. This may require a shift in public perceptions of loneliness. For example, many patients do not think of loneliness as a health issue to be discussed with their physicians. Likewise, physicians may have difficulties addressing loneliness due to its clinical assessment and a lack of evidence-based therapeutic options. In fact, we do not know how to best target loneliness, and we do not know if targeting loneliness would improve health outcome as appropriately designed trials have not been conducted.
Future research should better characterise the risk and protective factors of loneliness, as well as identifying effective therapeutic options.
With thanks to Elisabeth Lambert, Associate Professor at Swinburne University of Technology. You can learn more about A/Prof Lambert’s research interests and work here.
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