LONELINESS can significantly harm overall health by disrupting both immune and metabolic systems.

Loneliness is silently affecting millions worldwide. It affects individuals at all stages of life, not just older adults. Recent studies reveal that one in four adults experiences loneliness.

Although easy access to the internet and social media has changed how people live and talk to each other, more people still feel alone.

Chronic loneliness can have far-reaching implications for health, increasing the risk of conditions ranging from cardiovascular disease to dementia. Loneliness also affects stress responses, blood sugar levels, body composition (percentage of fat, bone and muscle in the body), metabolic disorder (conditions that affect the body’s ability to process food into energy and get rid of waste), cognitive abilities and mental health.

Stress is related to the release of cortisol, a hormone released in response to it. While cortisol has strong anti-inflammatory and immunosuppressive effects, prolonged elevated levels due to chronic stress can disrupt the immune system.

This disruption results in the increased production of pro-inflammatory cytokines or signalling proteins that help control inflammation in the body, leading to chronic inflammation in joints, the digestive tract, skin, lungs and blood vessels.

In the intricate web of human health, the profound impact of loneliness on the immune system often goes unnoticed.

Humans are social beings, and our well-being hinges on interaction, support, and engagement with others. However, merely having these social elements does not guarantee a sense of belonging.

Our perception of social relationships and interactions is shaped by the feeling of belonging or social integration. In the absence of the sense of belonging, loneliness sets in.

While there is no universally agreed definition of loneliness, many researchers define it as the difference between the social relationships someone has and those they desire.

However, loneliness and social isolation are different. Loneliness is a subjective feeling, whereas social isolation is an objective measure of social connectedness. It is, therefore, possible to feel lonely even when surrounded by friends and loved ones.

The experience of loneliness, regardless of one's social connections, can significantly impact health and well-being. Loneliness, now understood as a distinct and measurable psychological experience, is closely linked to poor health habits, increased stress and reduced ability of the body to repair itself.

Social detachment and feelings of isolation are major sources of enduring stress among adults. Changes like waiting longer to get married, more families where both parents work and more people living in single-family homes have made loneliness more common.

Our immune system  watches out for dangers. Even though it seems strong, there are weaknesses that can go unnoticed. The complex relationship between loneliness and immune function helps uncover both vulnerability and resilience ingrained in human biological composition.

Immune cells function through an intricate balance of release of a class of molecules called cytokines (signalling proteins that help control inflammation in the body). Their over-production can result in inflammatory responses (the immune system's response to harmful stimuli, such as pathogens, damaged cells, toxins, or irradiation) and affect other immune defence pathways.

A recent scientific study suggests that loneliness elevates inflammatory cytokines in the immune system resulting in heightened inflammation. It also suggests that loneliness can significantly harm overall health by disrupting both immune and metabolic systems.

It alters growth factors, acute-phase reactants (inflammation markers that exhibit significant changes in serum concentration during inflammation),  immunoglobulins (antibodies essential in protecting against bacteria, viruses, and fungi) and the body's antibody response to viruses and vaccines.

While the precise molecular mechanisms through which chronic loneliness impacts metabolic pathways linked to conditions such as cardiovascular disorders, early-onset of dementia and a weakened immune system remain unclear, a report published in 2023 by the United States Surgeon General suggests that the health risks associated with loneliness are as significant as those of obesity, sedentary lifestyle, and smoking.

Scientific studies also show that lonely people are very sensitive to negative words about social situations, like "disliked" or "rejected," and to faces that look unhappy. They also do not react as strongly to pictures of strangers having fun, which suggests  they may not enjoy positive interactions as much.

In the brain, being lonely for a long time can change areas that help understand others, know ourselves, and deal with emotions.

Even social media can have a multifaceted impact on loneliness.

Research indicates that higher levels of social media use are linked to increased feelings of loneliness and mental distress. This paradox highlights that while social media is designed to connect people, it can lead to virtual and superficial interactions and negative social comparisons.

It can reduce in-person contacts with others even within the same community, hindering rather than promoting social well-being.

Ultimately, the intent of usage and screen time are critical factors in determining whether social media contributes to loneliness or helps alleviate it.

Recognising the toll of loneliness on immune health is paramount. Currently, there are no pharmacological interventions to address health issues arising from loneliness. More research to understand the mechanisms linking loneliness and deteriorating health may lead to therapeutic interventions.

Community-based approaches and efforts can also be seriously considered to address the increasing problem of loneliness.

Humans need to relearn to share their time with others and take care of each other in their social setups to combat the fast-spreading epidemic of loneliness.




Virander Singh Chauhan is Chancellor of GITAM University, Arturo Falaschi Emeritus Scientist, International Centre for Genetic Engineering and Biotchnology, New Delhi and Distinguished Visiting Professor, Institution of Excellence Delhi University.


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