A Chinese-British study reveals that interactions with friends and family can strengthen our immune systems and keep us healthy. They would thus reduce the risks of heart disease, strokes, type 2 diabetes, etc.
There is growing evidence that social isolation and loneliness open the door to poor health and early death. These two situations notably increase mental fragility, promoting depression or cognitive decline.
Despite accumulating evidence, the underlying mechanisms by which social relationships impact health remain elusive. This is the task undertaken by a team led by scientists from the University of Cambridge, in the United Kingdom, and Fudan University, in China.
“One way to explore biological mechanisms is to look at proteins circulating in the blood“, they explain in their work published in the journal Nature Human Behaviour.
A question of protein
Based on this principle, they examined the “proteomes”, that is to say all the proteins, in blood samples from 42,000 adults aged 40 to 69 participating in the UK Biobank (a large database British data).
This allowed them to observe which proteins were present in greater quantities in socially isolated or lonely people, and how these proteins were linked to poor health. They thus identified 175 proteins associated with social isolation and 26 proteins with loneliness. Proteins produced in response to inflammation, viral infection or linked to cardiovascular disease, type 2 diabetes, stroke and premature death.
Thus, among the proteins identified, one particularly stands out: ADM. Produced in greater quantities in people suffering from loneliness, it is involved in the regulation of stress hormones and social hormones such as oxytocin, often nicknamed “the love hormone”. According to the authors, “the higher the ADM levels, the lower the volume of the insula, a brain region that allows us to sense what is happening inside our body,.”
Other proteins at higher levels were observed such as ASGR1. Which is associated with higher cholesterol levels and an increased risk of cardiovascular disease.
“These results highlight the importance of social contacts for our health“, underlines Professor Barbara Sahakian, from the department of psychiatry at the University of Cambridge. “More and more people of all ages report feeling alone. This is why the World Health Organization has described social isolation and loneliness as a global public health problem. We need to find ways to combat this growing problem and maintain connections between people to help them stay healthy.“
