Public health professionals have raised serious concerns over the growing health dangers associated with prolonged loneliness and social isolation, warning that people who live alone or feel emotionally disconnected face significantly higher risks of cardiovascular disease, depression, weakened immunity, and even premature death.
According to these experts, loneliness triggers the excessive release of stress hormones such as cortisol, which elevates blood pressure, heart rate, and blood sugar levels—key contributors to chronic conditions like heart disease and diabetes.
Highlighting the urgency of the issue, the World Health Organisation (WHO) revealed on Monday that more than 871,000 people die each year due to complications linked to loneliness. The global health body further disclosed that one in six people worldwide currently lives in loneliness or isolation—a crisis with serious physical and mental health implications.
Loneliness Harms More Than Just Mental Health
The WHO reported that loneliness increases the likelihood of stroke, heart attack, diabetes, anxiety, depression, and even suicide. Additionally, teenagers who report feeling lonely are 22% more likely to score lower grades, while adults who feel isolated often struggle to find or keep jobs, worsening economic and social inequality.
In an exclusive interview, Professor Tanimola Akande, a public health expert from the University of Ilorin, explained that loneliness not only exacerbates existing conditions such as diabetes and cardiovascular diseases, but also fosters harmful habits like inactivity and poor diet.
He stated, “People who feel isolated tend to move less and interact less. This lack of physical activity raises blood pressure, encourages weight gain, and increases the risk of metabolic disorders.”
Professor Akande added that prolonged solitude leads to sedentary lifestyles and negative thought patterns, which can spiral into mental health disorders such as depression, dementia, drug addiction, and even suicidal behavior.
Cortisol, Inflammation, and Early Death: The Science Behind the Danger
Another public health physician, Dr. Timothy Olusegun, emphasized that lonely individuals release excess cortisol, the body’s primary stress hormone. High levels of cortisol, he noted, cause inflammation, which contributes to a wide range of diseases.
Dr. Olusegun explained, “People who are lonely often develop unhealthy habits. They eat poorly, avoid physical activity, sleep badly, and withdraw from society—all of which negatively affect their overall well-being.”
Citing recent research, he revealed that social isolation and loneliness can increase the risk of death by up to 30%. Furthermore, lonely adults are 40% more likely to develop dementia or cognitive decline.
He added, “Chronic inflammation, triggered by long-term stress, leads to serious illnesses like type 2 diabetes, heart disease, rheumatoid arthritis, and even cancer.”
Loneliness Weakens the Immune System
According to the experts, loneliness also impairs immune function. Because lonely individuals produce fewer antibodies, they become more vulnerable to infections, chronic diseases, and possibly even tumors.
Dr. Olusegun warned that inflammation is the body’s emergency response mechanism. While useful for healing injuries, chronic inflammation occurs when this response never shuts off—leading to a breakdown in immune balance and creating pathways for disease.
WHO: One in Three Elderly People Are Isolated
In its latest findings, the WHO emphasized that one in three older adults and one in four teenagers are socially disconnected. The agency called for intentional public and private efforts to create environments where people can interact in person, free from technological distractions.
Scientific Evidence Confirms Loneliness Alters the Body
A landmark study published in the Proceedings of the National Academy of Sciences confirmed that loneliness reshapes the human immune system. The research, led by Professor John T. Cacioppo of the University of Chicago, analyzed white blood cells (leukocytes) in 141 adults aged 50–68 as part of the Chicago Health, Ageing, and Social Relations Study.
The team discovered that lonely individuals exhibited greater expression of a gene profile known as CTRA (Conserved Transcriptional Response to Adversity), which weakens antiviral responses while amplifying inflammation. Moreover, the study found that CTRA expression predicted future loneliness, and vice versa, showing a dangerous feedback loop between biology and emotions.
To further support their findings, the researchers examined rhesus macaque monkeys, a highly social species, from the California National Primate Research Center. These monkeys, subjected to perceived social isolation, showed elevated CTRA gene expression and higher levels of norepinephrine, a hormone involved in the fight-or-flight stress response.
Nigeria Faces Its Own Zoonotic Threats and Social Crises
While loneliness is a global issue, Nigeria has experienced significant fallout from social isolation. During the COVID-19 lockdowns between 2019 and 2020, millions of Nigerians reported worsening mental health, job losses, and increased domestic stress.
Additionally, experts have drawn connections between social isolation and increased vulnerability to zoonotic diseases, such as Lassa fever, Mpox, Ebola, and others that continue to threaten public health in the region.
Final Thoughts: Combating Loneliness is a Public Health Priority
Both WHO and local experts insist that reversing the loneliness epidemic requires coordinated action from governments, communities, and individuals. Solutions include creating safe spaces for interaction, reducing screen dependency, encouraging physical activity, and promoting mental health education.
“Protecting social bonds is just as important as vaccines or medication,” Dr. Olusegun concluded. “By nurturing connection, we safeguard not only our happiness but also our health.”
