Loneliness is bad for your health. Now we are closer to knowing why

    24 August 2016

    Harvard researchers have discovered a new link between loneliness and poor health.

    They found that people with fewer social connections had higher levels of fibrinogen — a protein that helps blood clots to form. Larger amounts raise the risk of heart attacks and strokes.

    Loneliness is known to activate stress hormones, producing fibrinogen in anticipation of injury. The clotting protein is necessary in order for the body to stop bleeding. However, too much fibrinogen can cause a build-up in the arteries and increase blood pressure.

    The researchers found that people with just five social connections had fibrinogen levels 20 per cent higher than people with 25 connections. They also suggested that having 12 fewer friends had the same effect on fibrinogen levels as taking up smoking.

    The study’s lead author, Dr David Kim, told the Telegraph: ‘Measurement of the whole social network can provide information about an individual’s cardiac risk that is not necessarily apparent to the individual herself.

    ‘Social connectedness displays a significant association with fibrinogen. If there is indeed an independent causal relationship between social isolation and fibrinogen and, subsequently, heart disease and stroke, then policies and interventions that improve social connectedness may have health effects even beyond the well-known benefits of improved economic conditions.’

    The research was published in the journal Proceedings of the Royal Society of London B: Biological Sciences.

    Instant analysis
    It has been known for many years that social isolation can have a significant negative impact on health and longevity, but the exact mechanism underlying this has always been unclear. This Harvard-based study takes us a step closer to now understanding why.

    Social isolation and loneliness now appears to be associated with a rise in the level of the body protein fibrinogen, which can raise blood pressure and increase the build-up of fatty deposits in our arteries, so increasing the risk of heart attacks and strokes.

    It is too early to be able to say that social isolation directly causes heart problems, but one thing does appear to be the case: being lonely is bad for your health.
    Research score: 4/5