lonely girl beach
© StoryblocksA lonely woman on a beach.

Loneliness may not be entirely down to a floundering social life. A new study has found that a person's gene coding may contribute to a crippling feeling of isolation.

Scientists at Cambridge University explored the biological causes of loneliness as well as whether the onset of life-threatening depressive feelings are a cause or symptom of social withdrawal.

During the study, which has been published in the journal Nature, researchers gleaned data from hundreds of thousands of people thanks to the UK Biobank. Using survey responses from 452,000 volunteers in the databank, the research team were able pinpoint 15 genomic loci that are likely to contribute to loneliness in certain people.

Our findings highlight the specific genetic basis for social isolation and social interaction," the researchers write. "We find evidence for shared genetic effects across social traits, in addition to more specific pathways that drive engagement in particular activities."

The study, entitled "Elucidating the genetic basis of social interaction and isolation," also found a causal link connecting cardio-metabolic health and social isolation. According the UK National Statistics Office, 5 percent of adults in England experience a regular feeling of loneliness.

Age UK state that around 3.6 million older people live alone and that loneliness can have a health impact as damaging as 15 cigarettes a day. Led by professor Felix Day, the Cambridge University study suggests a relationship between loneliness and obesity.

"We often think that loneliness is driven purely by our surrounding environment and life experiences, but this study demonstrates that genes can also play a role," John Perry, a University of Cambridge researcher, told The Telegraph.

"There is always a complex mix of genes and environment, but it does suggest that at a population level, if we could tackle obesity we would be able to bring down loneliness as well."