June 20, 2023 – People who are lonely or socially isolated have a dramatically increased risk of early death, according to a large new study.
Social isolation increased the risk of early death by 32%, and loneliness increased the risk of death by 14%, according to the study published Monday in an online edition of Nature Human Behaviour. Researchers combined data for more than 2 million adults from 90 previous studies published from 1986 to 2022.
The study also found numerous links between social isolation, loneliness, cancer, heart problems, and death.
Social isolation increased the risk of someone dying of cancer by 24%, or of heart problems by 34%. Loneliness increased the risk of someone dying of cancer by 9%.
People with heart problems had a 28% increased risk of dying from any cause (not just of a heart condition) if they were socially isolated, and they had a 51% increased risk of dying from breast cancer. People with breast cancer had a 33% increased risk of dying due to a cancer-related cause if they were socially isolated.
“It is therefore essential to improve the social relationship status of individuals with cancer, especially those with breast cancer, to prolong survival time,” the authors wrote.
The researchers defined social isolation as a lack of (or limited) social contact with other people, such as having a small social network, infrequent social contacts, or living alone. Loneliness was defined as having a feeling of stress due to having fewer social relationships than desired. Social isolation is considered to have traits that are objective, such as a specific number of relationships, while loneliness has subjective traits measured by how people feel about their relationships.
Previous research has linked social isolation and loneliness to poor health outcomes.
The researchers noted four major potential things linking social isolation, loneliness, and risk of death:
- Altered levels of the stress hormone cortisol, which affects a person’s glucose levels, metabolism, inflammatory response, reproductive system, and cardiovascular system
- Mental health impacts, particularly later in life, such as depression and cognitive decline
- Harmful behaviors like smoking, alcohol use, poor diet, and reduced exercise
- Less of a chance to get routine or emergency medical care due to a small social network
The authors wrote that lonely or socially isolated people are also more likely to receive poor medical care.
“Poor care provided by health care professionals who perceive this group as difficult to treat or time consuming further exacerbates adverse health outcomes,” they wrote.
The researchers, from Harbin Medical University in China, concluded that a “greater focus on social isolation and loneliness may help improve people’s well-being” and risk of death.