A recent study suggested ‘having no friends could be as deadly as smoking’ after discovering a link between loneliness and the level of a blood-clotting protein which can cause heart attacks and stroke.
Social isolation is known to activate the “fight or flight” stress signal which increases levels of the protein fibrinogen in anticipation of injury and blood loss. But too much fibrinogen is bad for health, raising blood pressure and causing the build-up of fatty deposits in the arteries.
Individuals with just five people in their social network had 20% higher levels fibrinogen than those with 25. Having 10-12 fewer friends had the same impact on levels of taking up smoking.
“Measurement of the whole social network can provide information about an individual’s cardiac risk that is not necessarily apparent to the individual herself,” said David Kim from Harvard.
“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.”
But although loneliness is often viewed as a problem for older people, a recent study by the Mental Health Foundation found that 18- to 34-year-olds were likely to feel lonely more often than over-55s.
“We can’t conclude from this research that social isolation directly causes heart problems. But the possibility that social factors can affect a protein in our blood, like fibrinogen, is an interesting prospect for further research in this area.”
Dr. Nicole Valtorta who led the University of York research said that “These findings are consistent with a growing body of research indicating that social relationships are important for health.”
Dr. Mike Knapton, the associate medical director at the British Heart Foundation, said that “BHF-funded research has already identified that social isolation can have a negative impact on your heart health.”