Loneliness and social isolation have been subjects of much debate in past studies, with some claiming these factors increase the risks of diseases and mortality. Recently, researchers at Harbin Medical University (HMU) in China conducted a comprehensive systematic review of 90 such studies, published between 1986 and 2022 and involving over 2.2 million subjects.

The systematic review uncovered a connection between social isolation and loneliness and a higher risk of death from various causes, including cancer and cardiovascular diseases. This finding is particularly significant for developed countries like Sweden, Japan, and the US, where the number of people living alone is on the rise.

While highlighting the ill effects of increasing loneliness among Americans, Vivek Murthy, the Surgeon General of the US recently told USA Today:

“Our epidemic of loneliness and isolation has been an underappreciated public health crisis that has harmed individual and societal health.” 

How do loneliness and isolation affect your health?

To comprehend how loneliness and isolation impact health, it is crucial to understand the distinction between the two. Social isolation refers to limited social contact and a small social circle, whereas loneliness is a subjective feeling stemming from unmet relationship desires.

While social isolation can lead to loneliness, one can feel lonely even when surrounded by people. In other words, you don’t have to be socially isolated to feel lonely but you are socially isolated when you spend most of your time alone. Both these conditions negatively affect mental health, promoting depression, anxiety, and unhealthy behaviors.

Individuals experiencing loneliness and isolation tend to avoid outdoor activities, physical exercise, social gatherings, and sharing emotions with others. As a result, they may suffer from sleep deprivation, malnutrition, and weakened immunity, making them susceptible to various illnesses.

Numerous studies support the HMU team’s findings. For instance, the American Heart Association reports that socially isolated or lonely individuals have a 29 percent higher chance of dying from a heart attack compared to socially active people. Additionally, loneliness increases the likelihood of dementia and stroke by 50 and 32 percent, respectively, according to a report from the National Academies of Sciences, Engineering, and Medicine. Furthermore, long-term social isolation or loneliness appears to be a risk factor for type 2 diabetes, with affected individuals twice as likely to develop the condition.

The implications are evident in cancer survival rates, where middle-aged male patients who have been single, widowed, or divorced for an extended period experience worse outcomes. Their likelihood of receiving an early cancer diagnosis is also diminished.

There are many other such studies that are in alignment with what the HMU team found during their analysis. Based on their findings, the researchers concluded:

“SI (social isolation) and loneliness are critical factors associated with an increased risk of all-cause, cardiovascular, and cancer mortality. Strategies are urgently needed to address this public health concern, such as raising awareness about the adverse health effects of SI and loneliness among health care professionals and the general public.” 

Reducing social isolation and loneliness should be a healthcare goal

While our healthcare system and society currently do not prioritize addressing social isolation and loneliness, the study emphasizes the need to identify and assist individuals with these conditions early on.

The researchers suggest that by reducing the levels of social isolation and loneliness in society we can drastically improve human health. Therefore, it’s important to develop solutions within our healthcare system for identifying these conditions at an early stage and providing appropriate assistance. 

Plus, there is also a need to rethink the way our society is structured in order to address loneliness and social isolation in a better way. 

“Our relationships are a source of healing and well-being hiding in plain sight – one that can help us live healthier, more fulfilled, and more productive lives. Given the significant health consequences of loneliness and isolation, we must prioritize building social connection the same way we have prioritized other critical public health issues such as tobacco, obesity, and substance use disorders,” said Murthy. 

The systematic review is published in the journal Nature.